1
|
Hovhannisyan Y, Li Z, Callon D, Suspène R, Batoumeni V, Canette A, Blanc J, Hocini H, Lefebvre C, El-Jahrani N, Kitsara M, L'honoré A, Kordeli E, Fornes P, Concordet JP, Tachdjian G, Rodriguez AM, Vartanian JP, Béhin A, Wahbi K, Joanne P, Agbulut O. Critical contribution of mitochondria in the development of cardiomyopathy linked to desmin mutation. Stem Cell Res Ther 2024; 15:10. [PMID: 38167524 PMCID: PMC10763022 DOI: 10.1186/s13287-023-03619-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2023] [Accepted: 12/18/2023] [Indexed: 01/05/2024] Open
Abstract
BACKGROUND Beyond the observed alterations in cellular structure and mitochondria, the mechanisms linking rare genetic mutations to the development of heart failure in patients affected by desmin mutations remain unclear due in part, to the lack of relevant human cardiomyocyte models. METHODS To shed light on the role of mitochondria in these mechanisms, we investigated cardiomyocytes derived from human induced pluripotent stem cells carrying the heterozygous DESE439K mutation that were either isolated from a patient or generated by gene editing. To increase physiological relevance, cardiomyocytes were either cultured on an anisotropic micropatterned surface to obtain elongated and aligned cardiomyocytes, or as a cardiac spheroid to create a micro-tissue. Moreover, when applicable, results from cardiomyocytes were confirmed with heart biopsies of suddenly died patient of the same family harboring DESE439K mutation, and post-mortem heart samples from five control healthy donors. RESULTS The heterozygous DESE439K mutation leads to dramatic changes in the overall cytoarchitecture of cardiomyocytes, including cell size and morphology. Most importantly, mutant cardiomyocytes display altered mitochondrial architecture, mitochondrial respiratory capacity and metabolic activity reminiscent of defects observed in patient's heart tissue. Finally, to challenge the pathological mechanism, we transferred normal mitochondria inside the mutant cardiomyocytes and demonstrated that this treatment was able to restore mitochondrial and contractile functions of cardiomyocytes. CONCLUSIONS This work highlights the deleterious effects of DESE439K mutation, demonstrates the crucial role of mitochondrial abnormalities in the pathophysiology of desmin-related cardiomyopathy, and opens up new potential therapeutic perspectives for this disease.
Collapse
Affiliation(s)
- Yeranuhi Hovhannisyan
- UMR CNRS 8256, INSERM U1164, Biological Adaptation and Ageing, Institut de Biologie Paris-Seine (IBPS), Sorbonne Université, 7, Quai St Bernard (case 256), 75005, Paris, France
| | - Zhenlin Li
- UMR CNRS 8256, INSERM U1164, Biological Adaptation and Ageing, Institut de Biologie Paris-Seine (IBPS), Sorbonne Université, 7, Quai St Bernard (case 256), 75005, Paris, France
| | - Domitille Callon
- UMR CNRS 8256, INSERM U1164, Biological Adaptation and Ageing, Institut de Biologie Paris-Seine (IBPS), Sorbonne Université, 7, Quai St Bernard (case 256), 75005, Paris, France
- Department of Pathology, Academic Hospital of Reims, Reims, France
| | - Rodolphe Suspène
- Virus and Cellular Stress Unit, Department of Virology, Institut Pasteur, Université Paris Cité, Paris, France
| | - Vivien Batoumeni
- UMR CNRS 8256, INSERM U1164, Biological Adaptation and Ageing, Institut de Biologie Paris-Seine (IBPS), Sorbonne Université, 7, Quai St Bernard (case 256), 75005, Paris, France
- Ksilink, Strasbourg, France
| | - Alexis Canette
- Service de Microscopie Électronique (IBPS-SME), Institut de Biologie Paris-Seine (IBPS), CNRS, Sorbonne Université, Paris, France
| | - Jocelyne Blanc
- UMR CNRS 8256, INSERM U1164, Biological Adaptation and Ageing, Institut de Biologie Paris-Seine (IBPS), Sorbonne Université, 7, Quai St Bernard (case 256), 75005, Paris, France
| | - Hakim Hocini
- INSERM U955, Equipe 16, Université Paris-Est Créteil, Créteil, France
| | - Cécile Lefebvre
- INSERM U955, Equipe 16, Université Paris-Est Créteil, Créteil, France
| | - Nora El-Jahrani
- INSERM U955, Equipe 16, Université Paris-Est Créteil, Créteil, France
| | - Maria Kitsara
- UMR CNRS 8256, INSERM U1164, Biological Adaptation and Ageing, Institut de Biologie Paris-Seine (IBPS), Sorbonne Université, 7, Quai St Bernard (case 256), 75005, Paris, France
| | - Aurore L'honoré
- UMR CNRS 8256, INSERM U1164, Biological Adaptation and Ageing, Institut de Biologie Paris-Seine (IBPS), Sorbonne Université, 7, Quai St Bernard (case 256), 75005, Paris, France
| | - Ekaterini Kordeli
- UMR CNRS 8256, INSERM U1164, Biological Adaptation and Ageing, Institut de Biologie Paris-Seine (IBPS), Sorbonne Université, 7, Quai St Bernard (case 256), 75005, Paris, France
| | - Paul Fornes
- Department of Pathology, Academic Hospital of Reims, Reims, France
| | - Jean-Paul Concordet
- INSERM U1154, CNRS UMR7196, Museum National d'Histoire Naturelle, Paris, France
| | - Gérard Tachdjian
- Laboratoire de Cytogénétique, Service d'Histologie-Embryologie-Cytogénétique, AP-HP, Hôpital Antoine Béclère, Université Paris Saclay, Clamart, France
| | - Anne-Marie Rodriguez
- UMR CNRS 8256, INSERM U1164, Biological Adaptation and Ageing, Institut de Biologie Paris-Seine (IBPS), Sorbonne Université, 7, Quai St Bernard (case 256), 75005, Paris, France
| | - Jean-Pierre Vartanian
- Virus and Cellular Stress Unit, Department of Virology, Institut Pasteur, Université Paris Cité, Paris, France
| | - Anthony Béhin
- Reference Center for Muscle Diseases Paris-Est, Myology Institute, AP-HP, Pitié-Salpêtrière Hospital, Sorbonne Université, Paris, France
| | - Karim Wahbi
- Cardiology Department, AP-HP, Cochin Hospital, Université Paris Cité, Paris, France
| | - Pierre Joanne
- UMR CNRS 8256, INSERM U1164, Biological Adaptation and Ageing, Institut de Biologie Paris-Seine (IBPS), Sorbonne Université, 7, Quai St Bernard (case 256), 75005, Paris, France.
| | - Onnik Agbulut
- UMR CNRS 8256, INSERM U1164, Biological Adaptation and Ageing, Institut de Biologie Paris-Seine (IBPS), Sorbonne Université, 7, Quai St Bernard (case 256), 75005, Paris, France.
| |
Collapse
|
2
|
Parker F, Tang AAS, Rogers B, Carrington G, dos Remedios C, Li A, Tomlinson D, Peckham M. Affimers targeting proteins in the cardiomyocyte Z-disc: Novel tools that improve imaging of heart tissue. Front Cardiovasc Med 2023; 10:1094563. [PMID: 36865889 PMCID: PMC9971620 DOI: 10.3389/fcvm.2023.1094563] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Accepted: 01/30/2023] [Indexed: 02/16/2023] Open
Abstract
Dilated Cardiomyopathy is a common form of heart failure. Determining how this disease affects the structure and organization of cardiomyocytes in the human heart is important in understanding how the heart becomes less effective at contraction. Here we isolated and characterised Affimers (small non-antibody binding proteins) to Z-disc proteins ACTN2 (α-actinin-2), ZASP (also known as LIM domain binding protein 3 or LDB3) and the N-terminal region of the giant protein titin (TTN Z1-Z2). These proteins are known to localise in both the sarcomere Z-discs and the transitional junctions, found close to the intercalated discs that connect adjacent cardiomyocytes. We use cryosections of left ventricles from two patients diagnosed with end-stage Dilated Cardiomyopathy who underwent Orthotopic Heart Transplantation and were whole genome sequenced. We describe how Affimers substantially improve the resolution achieved by confocal and STED microscopy compared to conventional antibodies. We quantified the expression of ACTN2, ZASP and TTN proteins in two patients with dilated cardiomyopathy and compared them with a sex- and age-matched healthy donor. The small size of the Affimer reagents, combined with a small linkage error (the distance from the epitope to the dye label covalently bound to the Affimer) revealed new structural details in Z-discs and intercalated discs in the failing samples. Affimers are thus useful for analysis of changes to cardiomyocyte structure and organisation in diseased hearts.
Collapse
Affiliation(s)
- Francine Parker
- School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom
| | - Anna A. S. Tang
- School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom
| | - Brendan Rogers
- School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom
| | - Glenn Carrington
- School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom
| | - Cris dos Remedios
- Mechanobiology Laboratory, Victor Chang Cardiac Research Institute, Darlinghurst, NSW, Australia
| | - Amy Li
- Sydney Heart Bank, The University of Sydney, Sydney, NSW, Australia
- Department of Pharmacy & Biomedical Sciences, La Trobe University, Bendigo, VIC, Australia
- Centre for Healthy Futures, Torrens University Australia, Surrey Hills, NSW, Australia
| | - Darren Tomlinson
- School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom
| | - Michelle Peckham
- School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom
| |
Collapse
|
3
|
Connecting macroscopic diffusion metrics of cardiac diffusion tensor imaging and microscopic myocardial structures based on simulation. Med Image Anal 2022; 77:102325. [DOI: 10.1016/j.media.2021.102325] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Revised: 11/26/2021] [Accepted: 11/29/2021] [Indexed: 11/20/2022]
|
4
|
Biophysical Reviews "Meet the Editor Series"-Elisabeth Ehler. Biophys Rev 2021; 13:579-581. [PMID: 34777613 DOI: 10.1007/s12551-021-00830-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Accepted: 08/14/2021] [Indexed: 10/20/2022] Open
|
5
|
Sanchez-Alonso JL, Loucks A, Schobesberger S, van Cromvoirt AM, Poulet C, Chowdhury RA, Trayanova N, Gorelik J. Nanoscale regulation of L-type calcium channels differentiates between ischemic and dilated cardiomyopathies. EBioMedicine 2020; 57:102845. [PMID: 32580140 PMCID: PMC7317229 DOI: 10.1016/j.ebiom.2020.102845] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Revised: 05/19/2020] [Accepted: 06/03/2020] [Indexed: 10/26/2022] Open
Abstract
BACKGROUND Subcellular localization and function of L-type calcium channels (LTCCs) play an important role in regulating contraction of cardiomyocytes. Understanding how this is affected by the disruption of transverse tubules during heart failure could lead to new insights into the disease. METHODS Cardiomyocytes were isolated from healthy donor hearts, as well as from patients with cardiomyopathies and with left ventricular assist devices. Scanning ion conductance and confocal microscopy was used to study membrane structures in the cells. Super-resolution scanning patch-clamp was used to examine LTCC function in different microdomains. Computational modeling predicted the impact of these changes to arrhythmogenesis at the whole-heart level. FINDINGS We showed that loss of structural organization in failing myocytes leads to re-distribution of functional LTCCs from the T-tubules to the sarcolemma. In ischemic cardiomyopathy, the increased LTCC open probability in the T-tubules depends on the phosphorylation by protein kinase A, whereas in dilated cardiomyopathy, the increased LTCC opening probability in the sarcolemma results from enhanced phosphorylation by calcium-calmodulin kinase II. LVAD implantation corrected LTCCs pathophysiological activity, although it did not improve their distribution. Using computational modeling in a 3D anatomically-realistic human ventricular model, we showed how LTCC location and activity can trigger heart rhythm disorders of different severity. INTERPRETATION Our findings demonstrate that LTCC redistribution and function differentiate between disease aetiologies. The subcellular changes observed in specific microdomains could be the consequence of the action of distinct protein kinases. FUNDING This work was supported by NIH grant (ROI-HL 126802 to NT-JG) and British Heart Foundation (grant RG/17/13/33173 to JG, project grant PG/16/17/32069 to RAC). Funders had no role in study design, data collection, data analysis, interpretation, writing of the report.
Collapse
Affiliation(s)
- Jose L Sanchez-Alonso
- Department of Cardiovascular Sciences, Imperial Centre for Translational and Experimental Medicine, National Heart and Lung Institute, Imperial College London, London W120NN, UK
| | - Alexandra Loucks
- Department of Biomedical Engineering and Alliance for Cardiovascular Diagnostic and Treatment Innovation, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Sophie Schobesberger
- Department of Cardiovascular Sciences, Imperial Centre for Translational and Experimental Medicine, National Heart and Lung Institute, Imperial College London, London W120NN, UK
| | - Ankie M van Cromvoirt
- Department of Cardiovascular Sciences, Imperial Centre for Translational and Experimental Medicine, National Heart and Lung Institute, Imperial College London, London W120NN, UK
| | - Claire Poulet
- Department of Cardiovascular Sciences, Imperial Centre for Translational and Experimental Medicine, National Heart and Lung Institute, Imperial College London, London W120NN, UK
| | - Rasheda A Chowdhury
- Department of Cardiovascular Sciences, Imperial Centre for Translational and Experimental Medicine, National Heart and Lung Institute, Imperial College London, London W120NN, UK
| | - Natalia Trayanova
- Department of Biomedical Engineering and Alliance for Cardiovascular Diagnostic and Treatment Innovation, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Julia Gorelik
- Department of Cardiovascular Sciences, Imperial Centre for Translational and Experimental Medicine, National Heart and Lung Institute, Imperial College London, London W120NN, UK.
| |
Collapse
|
6
|
Enomoto H, Mittal N, Inomata T, Arimura T, Izumi T, Kimura A, Fukuda K, Makino S. Dilated cardiomyopathy-linked heat shock protein family D member 1 mutations cause up-regulation of reactive oxygen species and autophagy through mitochondrial dysfunction. Cardiovasc Res 2020; 117:1118-1131. [PMID: 32520982 DOI: 10.1093/cvr/cvaa158] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/19/2018] [Revised: 07/01/2019] [Accepted: 06/04/2020] [Indexed: 01/08/2023] Open
Abstract
AIMS During heart failure, the levels of circulatory heat shock protein family D member 1 (HSP60) increase. However, its underlying mechanism is still unknown. The apical domain of heat shock protein family D member 1 (HSPD1) is conserved throughout evolution. We found a point mutation in HSPD1 in a familial dilated cardiomyopathy (DCM) patient. A similar point mutation in HSPD1 in the zebrafish mutant, nbl, led to loss of its regenerative capacity and development of pericardial oedema under heat stress condition. In this study, we aimed to determine the direct involvement of HSPD1 in the development of DCM. METHODS AND RESULTS By Sanger method, we found a point mutation (Thr320Ala) in the apical domain of HSPD1, in one familial DCM patient, which was four amino acids away from the point mutation (Val324Glu) in the nbl mutant zebrafish. The nbl mutants showed atrio-ventricular block and sudden death at 8-month post-fertilization. Histological and microscopic analysis of the nbl mutant hearts showed decreased ventricular wall thickness, elevated level of reactive oxygen species (ROS), increased fibrosis, mitochondrial damage, and increased autophagosomes. mRNA and protein expression of autophagy-related genes significantly increased in nbl mutants. We established HEK293 stable cell lines of wild-type, nbl-type, and DCM-type HSPD1, with tetracycline-dependent expression. Compared to wild-type, both nbl- and DCM-type cells showed decreased cell growth, increased expression of ROS and autophagy-related genes, inhibition of the activity of mitochondrial electron transport chain complexes III and IV, and decreased mitochondrial fission and fusion. CONCLUSION Mutations in HSPD1 caused mitochondrial dysfunction and induced mitophagy. Mitochondrial dysfunction caused increased ROS and cardiac atrophy.
Collapse
Affiliation(s)
- Hirokazu Enomoto
- Department of Cardiology, Keio University School of Medicine, Tokyo 160-8582, Japan
| | - Nishant Mittal
- Department of Cardiology, Keio University School of Medicine, Tokyo 160-8582, Japan
| | - Takayuki Inomata
- Department of Cardiovascular Medicine, Kitasato University School of Medicine, Kanagawa 252-0374, Japan
| | - Takuro Arimura
- Department of Molecular Pathogenesis, Tokyo Medical and Dental University, Tokyo 113-8510, Japan
| | - Tohru Izumi
- Department of Cardiovascular Medicine, Kitasato University School of Medicine, Kanagawa 252-0374, Japan
| | - Akinori Kimura
- Department of Molecular Pathogenesis, Tokyo Medical and Dental University, Tokyo 113-8510, Japan
| | - Keiichi Fukuda
- Department of Cardiology, Keio University School of Medicine, Tokyo 160-8582, Japan
| | - Shinji Makino
- Department of Cardiology, Keio University School of Medicine, Tokyo 160-8582, Japan.,Health Center, Keio University, Tokyo 160-8582, Japan
| |
Collapse
|
7
|
Kagemoto T, Oyama K, Yamane M, Tsukamoto S, Kobirumaki-Shimozawa F, Li A, Dos Remedios C, Fukuda N, Ishiwata S. Sarcomeric Auto-Oscillations in Single Myofibrils From the Heart of Patients With Dilated Cardiomyopathy. Circ Heart Fail 2019; 11:e004333. [PMID: 29980594 DOI: 10.1161/circheartfailure.117.004333] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/23/2017] [Accepted: 05/31/2018] [Indexed: 01/30/2023]
Abstract
BACKGROUND Left ventricular wall motion is depressed in patients with dilated cardiomyopathy (DCM). However, whether or not the depressed left ventricular wall motion is caused by impairment of sarcomere dynamics remains to be fully clarified. METHODS AND RESULTS We analyzed the mechanical properties of single sarcomere dynamics during sarcomeric auto-oscillations (calcium spontaneous oscillatory contractions [Ca-SPOC]) that occurred at partial activation under the isometric condition in myofibrils from donor hearts and from patients with severe DCM (New York Heart Association classification III-IV). Ca-SPOC reproducibly occurred in the presence of 1 μmol/L free Ca2+ in both nonfailing and DCM myofibrils, and sarcomeres exhibited a saw-tooth waveform along single myofibrils composed of quick lengthening and slow shortening. The period of Ca-SPOC was longer in DCM myofibrils than in nonfailing myofibrils, in association with prolonged shortening time. Lengthening time was similar in both groups. Then, we performed Tn (troponin) exchange in myofibrils with a DCM-causing homozygous mutation (K36Q) in cTnI (cardiac TnI). On exchange with the Tn complex from healthy porcine ventricles, period, shortening time, and shortening velocity in cTnI-K36Q myofibrils became similar to those in Tn-reconstituted nonfailing myofibrils. Protein kinase A abbreviated period in both Tn-reconstituted nonfailing and cTnI-K36Q myofibrils, demonstrating acceleration of cross-bridge kinetics. CONCLUSIONS Sarcomere dynamics was found to be depressed under loaded conditions in DCM myofibrils because of impairment of thick-thin filament sliding. Thus, microscopic analysis of Ca-SPOC in human cardiac myofibrils is beneficial to systematically unveil the kinetic properties of single sarcomeres in various types of heart disease.
Collapse
Affiliation(s)
- Tatsuya Kagemoto
- Department of Physics, Faculty of Science and Engineering, Waseda University, Tokyo, Japan (T.K., M.Y., S.I.)
| | - Kotaro Oyama
- Department of Cell Physiology, The Jikei University School of Medicine, Tokyo, Japan (K.O., S.T., F.K.-S., N.F.)
| | - Mitsunori Yamane
- Department of Physics, Faculty of Science and Engineering, Waseda University, Tokyo, Japan (T.K., M.Y., S.I.)
| | - Seiichi Tsukamoto
- Department of Cell Physiology, The Jikei University School of Medicine, Tokyo, Japan (K.O., S.T., F.K.-S., N.F.)
| | - Fuyu Kobirumaki-Shimozawa
- Department of Cell Physiology, The Jikei University School of Medicine, Tokyo, Japan (K.O., S.T., F.K.-S., N.F.)
| | - Amy Li
- School of Medical Sciences, Bosch Institute, The University of Sydney, Australia (A.L., C.D.R.)
| | - Cristobal Dos Remedios
- School of Medical Sciences, Bosch Institute, The University of Sydney, Australia (A.L., C.D.R.)
| | - Norio Fukuda
- Department of Cell Physiology, The Jikei University School of Medicine, Tokyo, Japan (K.O., S.T., F.K.-S., N.F.).
| | - Shin'ichi Ishiwata
- Department of Physics, Faculty of Science and Engineering, Waseda University, Tokyo, Japan (T.K., M.Y., S.I.).
| |
Collapse
|
8
|
Hall D. A note of appreciation for Prof. Cristobal dos Remedios on behalf of Biophysical Reviews. Biophys Rev 2019; 11:129-130. [PMID: 30783907 DOI: 10.1007/s12551-019-00505-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Accepted: 02/11/2019] [Indexed: 12/19/2022] Open
Abstract
Following the initial five-year tenure (2009-2014) of the founding Chief Editor, Dr. Jean Garnier, Prof. Cristobal dos Remedios (University of Sydney) assumed responsibility for Biophysical Reviews as the second Chief Editor (2014-2019). Under his stewardship, Biophysical Reviews has become a six issue per year journal, publishing approximately 100 reviews per year. At the conclusion of his five-year tenure as Chief Editor (and at the age of 78), Cris is stepping down, leaving the journal well placed to apply for (and receive) an impact factor in 2020. On behalf of the journal, I would like to take the occasion of his retirement as Chief Editor to thank Cris for his dedicated service to Biophysical Reviews, and also welcome him to his new position as Emeritus Chief Editor.
Collapse
Affiliation(s)
- Damien Hall
- Laboratory for Multiscale Structural Biology, Institute for Protein Research, Osaka University, 3-1-Yamadaoka, Suita, Osaka, 565-0871, Japan.
| |
Collapse
|
9
|
Kessler EL, van Stuijvenberg L, van Bavel JJA, van Bennekom J, Zwartsen A, Rivaud MR, Vink A, Efimov IR, Postma AV, van Tintelen JP, Remme CA, Vos MA, Banning A, de Boer TP, Tikkanen R, van Veen TAB. Flotillins in the intercalated disc are potential modulators of cardiac excitability. J Mol Cell Cardiol 2018; 126:86-95. [PMID: 30452906 DOI: 10.1016/j.yjmcc.2018.11.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Revised: 11/12/2018] [Accepted: 11/13/2018] [Indexed: 01/24/2023]
Abstract
BACKGROUND The intercalated disc (ID) is important for cardiac remodeling and has become a subject of intensive research efforts. However, as yet the composition of the ID has still not been conclusively resolved and the role of many proteins identified in the ID, like Flotillin-2, is often unknown. The Flotillin proteins are known to be involved in the stabilization of cadherins and desmosomes in the epidermis and upon cancer development. However, their role in the heart has so far not been investigated. Therefore, in this study, we aimed at identifying the role of Flotillin-1 and Flotillin-2 in the cardiac ID. METHODS Location of Flotillins in human and murine cardiac tissue was evaluated by fluorescent immunolabeling and co-immunoprecipitation. In addition, the effect of Flotillin knockout (KO) on proteins of the ID and in electrical excitation and conduction was investigated in cardiac samples of wildtype (WT), Flotillin-1 KO, Flotilin-2 KO and Flotilin-1/2 double KO mice. Consequences of Flotillin knockdown (KD) on cardiac function were studied (patch clamp and Multi Electrode Array (MEA)) in neonatal rat cardiomyocytes (NRCMs) transfected with siRNAs against Flotillin-1 and/or Flotillin-2. RESULTS First, we confirmed presence in the ID and mutual binding of Flotillin-1 and Flotillin-2 in murine and human cardiac tissue. Flotillin KO mice did not show cardiac fibrosis, nor hypertrophy or changes in expression of the desmosomal ID proteins. However, protein expression of the cardiac sodium channel NaV1.5 was significantly decreased in Flotillin-1 and Flotillin-1/2 KO mice compared to WT mice. In addition, sodium current density showed a significant decrease upon Flotillin-1/2 KD in NRCMs as compared to scrambled siRNA-transfected NRCMs. MEA recordings of Flotillin-2 KD NRCM cultures showed a significantly decreased spike amplitude and a tendency of a reduced spike slope when compared to control and scrambled siRNA-transfected cultures. CONCLUSIONS In this study, we demonstrate the presence of Flotillin-1, in addition to Flotillin-2 in the cardiac ID. Our findings indicate a modulatory role of Flotillins on NaV1.5 expression at the ID, with potential consequences for cardiac excitation.
Collapse
Affiliation(s)
- Elise L Kessler
- Department of Medical Physiology, Division of Heart & Lungs, University Medical Center Utrecht, Utrecht, the Netherlands.
| | - Leonie van Stuijvenberg
- Department of Medical Physiology, Division of Heart & Lungs, University Medical Center Utrecht, Utrecht, the Netherlands
| | - Joanne J A van Bavel
- Department of Medical Physiology, Division of Heart & Lungs, University Medical Center Utrecht, Utrecht, the Netherlands
| | - Joëlle van Bennekom
- Department of Medical Physiology, Division of Heart & Lungs, University Medical Center Utrecht, Utrecht, the Netherlands
| | - Anne Zwartsen
- Dutch Poisons Information Center (DPIC), University Medical Center Utrecht, Utrecht University, Utrecht, the Netherlands; Neurotoxicology Research Group, Division Toxicology, Institute for Risk Assessment Sciences (IRAS), Faculty of Veterinary Medicine, Utrecht University, Utrecht, the Netherlands
| | - Mathilde R Rivaud
- Department of Medical Physiology, Division of Heart & Lungs, University Medical Center Utrecht, Utrecht, the Netherlands
| | - Aryan Vink
- Department of Pathology, University Medical Center Utrecht, Utrecht, the Netherlands
| | - Igor R Efimov
- Department of Biomedical Engineering, George Washington University, Washington, DC, USA
| | - Alex V Postma
- Department of Clinical Genetics, Amsterdam University Medical Center, Location AMC, the Netherlands
| | - J Peter van Tintelen
- Department of Clinical Genetics, Amsterdam University Medical Center, Location AMC, the Netherlands; Department of Genetics, University Medical Center Utrecht, Utrecht, the Netherlands
| | - Carol A Remme
- Department of Clinical and Experimental Cardiology, Academic Medical Center, University of Amsterdam, the Netherlands
| | - Marc A Vos
- Department of Medical Physiology, Division of Heart & Lungs, University Medical Center Utrecht, Utrecht, the Netherlands
| | - Antje Banning
- Institute of Biochemistry, Medical Faculty, University of Giessen, Germany
| | - Teun P de Boer
- Department of Medical Physiology, Division of Heart & Lungs, University Medical Center Utrecht, Utrecht, the Netherlands
| | - Ritva Tikkanen
- Institute of Biochemistry, Medical Faculty, University of Giessen, Germany
| | - Toon A B van Veen
- Department of Medical Physiology, Division of Heart & Lungs, University Medical Center Utrecht, Utrecht, the Netherlands
| |
Collapse
|
10
|
Non-sarcomeric causes of heart failure: a Sydney Heart Bank perspective. Biophys Rev 2018; 10:949-954. [PMID: 30022358 DOI: 10.1007/s12551-018-0441-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Accepted: 07/03/2018] [Indexed: 12/14/2022] Open
|
11
|
Gehmlich K, Ehler E. Non-sarcomeric causes of heart failure. Biophys Rev 2018; 10:943-947. [PMID: 30008146 DOI: 10.1007/s12551-018-0444-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Accepted: 07/05/2018] [Indexed: 12/27/2022] Open
Affiliation(s)
- Katja Gehmlich
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine and British Heart Foundation Centre of Research Excellence, University of Oxford, Oxford, UK
| | - Elisabeth Ehler
- Randall Centre for Cell and Molecular Biophysics, School of Basic and Medical Biosciences, Room 3.26A, New Hunt's House, Guy's Campus, London, SE1 1UL, UK.
- School of Cardiovascular Medicine and Sciences, British Heart Foundation Research Excellence Centre, King's College London, London, UK.
| |
Collapse
|
12
|
Ehler E. Actin-associated proteins and cardiomyopathy-the 'unknown' beyond troponin and tropomyosin. Biophys Rev 2018; 10:1121-1128. [PMID: 29869751 PMCID: PMC6082317 DOI: 10.1007/s12551-018-0428-1] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Accepted: 05/18/2018] [Indexed: 02/06/2023] Open
Abstract
It has been known for several decades that mutations in genes that encode for proteins involved in the control of actomyosin interactions such as the troponin complex, tropomyosin and MYBP-C and thus regulate contraction can lead to hereditary hypertrophic cardiomyopathy. In recent years, it has become apparent that actin-binding proteins not directly involved in the regulation of contraction also can exhibit changed expression levels, show altered subcellular localisation or bear mutations that might lead to hereditary cardiomyopathies. The aim of this review is to look beyond the troponin/tropomyosin mechanism and to give an overview of the different types of actin-associated proteins and their potential roles in cardiomyocytes. It will then discuss recent findings relevant to their involvement in heart disease.
Collapse
Affiliation(s)
- Elisabeth Ehler
- Randall Centre for Cell and Molecular Biophysics (School of Basic and Medical Biosciences), London, UK. .,School of Cardiovascular Medicine and Sciences, British Heart Foundation Research Excellence Centre, King's College London, Room 3.26A, New Hunt's House, Guy's Campus, London, SE1 1UL, UK.
| |
Collapse
|
13
|
Buttner P, Galli R, Husser D, Bollmann A. Label-free Imaging of Myocardial Remodeling in Atrial Fibrillation Using Nonlinear Optical Microscopy: A Feasibility Study. J Atr Fibrillation 2018; 10:1644. [PMID: 29988238 DOI: 10.4022/jafib.1644] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2018] [Revised: 02/23/2018] [Accepted: 02/24/2018] [Indexed: 01/21/2023]
Abstract
Atrial fibrillation, characterized by rapid disorganized electrical activation of myocardium, is caused by and accompanied by remodeling of myocardial tissue. We applied nonlinear optical microscopy (NLOM) to visualize typical myocardial features and atrial fibrillation effects in order to test anon-destructive imaging technology that in principle can be applied in vivo.Coherent anti-Stokes Raman scattering, endogenous two-photon excited fluorescence, and second harmonic generation were used to inspect unstained human atrial myocardium from three patients who underwent surgical Cox-MAZE procedure with amputation of left atrial appendage. Using NLOM techniques, we collected detailrich pictures of unstained tissue that enable comprehensive characterization of myocardial characteristics like myocyte structure, collagen and lipofuscin deposition, intercalating disc width, and fatty degradation. Development of in vivo application of the NLOM technique may represent a revolutionary approach in characterizing atrial fibrillation associated myocardial remodeling with important implications for therapy individualization and monitoring.
Collapse
Affiliation(s)
- Petra Buttner
- Department of Electrophysiology, Heart Center Leipzig, Strumpellstrabe 39, 04289 Leipzig, Germany
| | - Roberta Galli
- Clinical Sensoring and Monitoring, Department of Anesthesiology and Intensive Care Medicine, Faculty of Medicine Carl Gustav Carus, TU Dresden, Fetscherstrabe 74, 01307 Dresden, Germany
| | - Daniela Husser
- Department of Electrophysiology, Heart Center Leipzig, Strumpellstrabe 39, 04289 Leipzig, Germany
| | - Andreas Bollmann
- Department of Electrophysiology, Heart Center Leipzig, Strumpellstrabe 39, 04289 Leipzig, Germany
| |
Collapse
|
14
|
Chu M, Novak SM, Cover C, Wang AA, Chinyere IR, Juneman EB, Zarnescu DC, Wong PK, Gregorio CC. Increased Cardiac Arrhythmogenesis Associated With Gap Junction Remodeling With Upregulation of RNA-Binding Protein FXR1. Circulation 2017; 137:605-618. [PMID: 29101288 DOI: 10.1161/circulationaha.117.028976] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/14/2017] [Accepted: 10/23/2017] [Indexed: 11/16/2022]
Abstract
BACKGROUND Gap junction remodeling is well established as a consistent feature of human heart disease involving spontaneous ventricular arrhythmia. The mechanisms responsible for gap junction remodeling that include alterations in the distribution of, and protein expression within, gap junctions are still debated. Studies reveal that multiple transcriptional and posttranscriptional regulatory pathways are triggered in response to cardiac disease, such as those involving RNA-binding proteins. The expression levels of FXR1 (fragile X mental retardation autosomal homolog 1), an RNA-binding protein, are critical to maintain proper cardiac muscle function; however, the connection between FXR1 and disease is not clear. METHODS To identify the mechanisms regulating gap junction remodeling in cardiac disease, we sought to identify the functional properties of FXR1 expression, direct targets of FXR1 in human left ventricle dilated cardiomyopathy (DCM) biopsy samples and mouse models of DCM through BioID proximity assay and RNA immunoprecipitation, how FXR1 regulates its targets through RNA stability and luciferase assays, and functional consequences of altering the levels of this important RNA-binding protein through the analysis of cardiac-specific FXR1 knockout mice and mice injected with 3xMyc-FXR1 adeno-associated virus. RESULTS FXR1 expression is significantly increased in tissue samples from human and mouse models of DCM via Western blot analysis. FXR1 associates with intercalated discs, and integral gap junction proteins Cx43 (connexin 43), Cx45 (connexin 45), and ZO-1 (zonula occludens-1) were identified as novel mRNA targets of FXR1 by using a BioID proximity assay and RNA immunoprecipitation. Our findings show that FXR1 is a multifunctional protein involved in translational regulation and stabilization of its mRNA targets in heart muscle. In addition, introduction of 3xMyc-FXR1 via adeno-associated virus into mice leads to the redistribution of gap junctions and promotes ventricular tachycardia, showing the functional significance of FXR1 upregulation observed in DCM. CONCLUSIONS In DCM, increased FXR1 expression appears to play an important role in disease progression by regulating gap junction remodeling. Together this study provides a novel function of FXR1, namely, that it directly regulates major gap junction components, contributing to proper cell-cell communication in the heart.
Collapse
Affiliation(s)
- Miensheng Chu
- Department of Cellular and Molecular Medicine and Sarver Molecular Cardiovascular Research Program (M.C., S.M.N., C.C., A.A.W., C.C.G.)
| | - Stefanie Mares Novak
- Department of Cellular and Molecular Medicine and Sarver Molecular Cardiovascular Research Program (M.C., S.M.N., C.C., A.A.W., C.C.G.)
| | - Cathleen Cover
- Department of Cellular and Molecular Medicine and Sarver Molecular Cardiovascular Research Program (M.C., S.M.N., C.C., A.A.W., C.C.G.)
| | - Anne A Wang
- Department of Cellular and Molecular Medicine and Sarver Molecular Cardiovascular Research Program (M.C., S.M.N., C.C., A.A.W., C.C.G.)
| | | | | | | | - Pak Kin Wong
- University of Arizona, Tucson. Department of Biomedical Engineering at Pennsylvania State University, University Park (P.K.W.)
| | - Carol C Gregorio
- Department of Cellular and Molecular Medicine and Sarver Molecular Cardiovascular Research Program (M.C., S.M.N., C.C., A.A.W., C.C.G.)
| |
Collapse
|
15
|
Luciani M, Del Monte F. Insights from Second-Line Treatments for Idiopathic Dilated Cardiomyopathy. J Cardiovasc Dev Dis 2017; 4:jcdd4030012. [PMID: 29367542 PMCID: PMC5715707 DOI: 10.3390/jcdd4030012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Revised: 08/18/2017] [Accepted: 08/19/2017] [Indexed: 12/20/2022] Open
Abstract
Background: Dilated cardiomyopathy (DCM) is an independent nosographic entity characterized by left ventricular dilatation and contractile dysfunction leading to heart failure (HF). The idiopathic form of DCM (iDCM) occurs in the absence of coronaropathy or other known causes of DCM. Despite being different from other forms of HF for demographic, clinical, and prognostic features, its current pharmacological treatment does not significantly diverge. Methods: In this study we performed a Pubmed library search for placebo-controlled clinical investigations and a post-hoc analysis recruiting iDCM from 1985 to 2016. We searched for second-line pharmacologic treatments to reconsider drugs for iDCM management and pinpoint pathological mechanisms. Results: We found 33 clinical studies recruiting a total of 3392 patients of various durations and sizes, as well as studies that tested different drug classes (statins, pentoxifylline, inotropes). A metanalysis was unfeasible, although a statistical significance for changes upon treatment for molecular results, morphofunctional parameters, and clinical endpoints was reported. Statins appeared to be beneficial in light of their pleiotropic effects; inotropes might be tolerated more for longer times in iDCM compared to ischemic patients. General anti-inflammatory therapies do not significantly improve outcomes. Metabolic and growth modulation remain appealing fields to be investigated. Conclusions: The evaluation of drug effectiveness based on direct clinical benefit is an inductive method providing evidence-based insights. This backward approach sheds light on putative and underestimated pathologic mechanisms and thus therapeutic targets for iDCM management.
Collapse
Affiliation(s)
- Marco Luciani
- Department of Cardiovascular Sciences, Università Cattolica del Sacro Cuore, Largo A. Gemelli, 8, 00168 Rome, Italy.
| | - Federica Del Monte
- Department of Medicine, Medical University of South Carolina, Charleston, SC 29425, USA.
| |
Collapse
|
16
|
Dos Remedios CG, Lal SP, Li A, McNamara J, Keogh A, Macdonald PS, Cooke R, Ehler E, Knöll R, Marston SB, Stelzer J, Granzier H, Bezzina C, van Dijk S, De Man F, Stienen GJM, Odeberg J, Pontén F, Linke WA, Linke W, van der Velden J. The Sydney Heart Bank: improving translational research while eliminating or reducing the use of animal models of human heart disease. Biophys Rev 2017; 9:431-441. [PMID: 28808947 DOI: 10.1007/s12551-017-0305-3] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2017] [Accepted: 07/31/2017] [Indexed: 01/09/2023] Open
Abstract
The Sydney Heart Bank (SHB) is one of the largest human heart tissue banks in existence. Its mission is to provide high-quality human heart tissue for research into the molecular basis of human heart failure by working collaboratively with experts in this field. We argue that, by comparing tissues from failing human hearts with age-matched non-failing healthy donor hearts, the results will be more relevant than research using animal models, particularly if their physiology is very different from humans. Tissue from heart surgery must generally be used soon after collection or it significantly deteriorates. Freezing is an option but it raises concerns that freezing causes substantial damage at the cellular and molecular level. The SHB contains failing samples from heart transplant patients and others who provided informed consent for the use of their tissue for research. All samples are cryopreserved in liquid nitrogen within 40 min of their removal from the patient, and in less than 5-10 min in the case of coronary arteries and left ventricle samples. To date, the SHB has collected tissue from about 450 failing hearts (>15,000 samples) from patients with a wide range of etiologies as well as increasing numbers of cardiomyectomy samples from patients with hypertrophic cardiomyopathy. The Bank also has hearts from over 120 healthy organ donors whose hearts, for a variety of reasons (mainly tissue-type incompatibility with waiting heart transplant recipients), could not be used for transplantation. Donor hearts were collected by the St Vincent's Hospital Heart and Lung transplantation team from local hospitals or within a 4-h jet flight from Sydney. They were flushed with chilled cardioplegic solution and transported to Sydney where they were quickly cryopreserved in small samples. Failing and/or donor samples have been used by more than 60 research teams around the world, and have resulted in more than 100 research papers. The tissues most commonly requested are from donor left ventricles, but right ventricles, atria, interventricular system, and coronary arteries vessels have also been reported. All tissues are stored for long-term use in liquid N or vapor (170-180 °C), and are shipped under nitrogen vapor to avoid degradation of sensitive molecules such as RNAs and giant proteins. We present evidence that the availability of these human heart samples has contributed to a reduction in the use of animal models of human heart failure.
Collapse
Affiliation(s)
- C G Dos Remedios
- Sydney Heart Bank, Discipline of Anatomy & Histology, University of Sydney, Sydney, Australia.
| | - S P Lal
- Sydney Heart Bank, Discipline of Anatomy & Histology, University of Sydney, Sydney, Australia
| | - A Li
- Sydney Heart Bank, Discipline of Anatomy & Histology, University of Sydney, Sydney, Australia.,Department of Molecular Physiology and Biophysics, University of Vermont, Burlington, VT, USA
| | - J McNamara
- Sydney Heart Bank, Discipline of Anatomy & Histology, University of Sydney, Sydney, Australia
| | - A Keogh
- Heart Transplant Unit, St Vincent's Hospital, Sydney, Australia
| | - P S Macdonald
- Heart Transplant Unit, St Vincent's Hospital, Sydney, Australia
| | - R Cooke
- Cardiovascular Research Institute, University of California San Francisco, California, USA
| | - E Ehler
- Cardiovascular Division, Randall Division of Cell and Molecular Biophysics, London, UK
| | - R Knöll
- Department of Medicine, Karolinska Institutet, Huddinge, Sweden
| | - S B Marston
- National Heart and Lung Institute, Imperial College London, London, UK
| | - J Stelzer
- Department of Physiology & Biophysics, Case Western Reserve University, Cleveland, OH, USA
| | - H Granzier
- Molecular Cardiovascular Research Program, University of Arizona, Tucson, USA
| | - C Bezzina
- Department of Experimental Cardiology, Heart Failure Research Center, Amsterdam, The Netherlands
| | - S van Dijk
- Department of Physiology, Institute for Cardiovascular Research, VU University Medical Center, Amsterdam, The Netherlands
| | - F De Man
- Department of Physiology, Institute for Cardiovascular Research, VU University Medical Center, Amsterdam, The Netherlands
| | - G J M Stienen
- Department of Physiology, Institute for Cardiovascular Research, VU University Medical Center, Amsterdam, The Netherlands
| | - J Odeberg
- Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden
| | - F Pontén
- Science for Life Laboratory, KTH-Royal Institute of Technology, Stockholm, Sweden
| | | | - W Linke
- Ruhr University, Bochum, Germany
| | - J van der Velden
- Department of Physiology, Institute for Cardiovascular Research, VU University Medical Center, Amsterdam, The Netherlands
| |
Collapse
|
17
|
Kessler EL, Nikkels PG, van Veen TA. Disturbed Desmoglein-2 in the intercalated disc of pediatric patients with dilated cardiomyopathy. Hum Pathol 2017; 67:101-108. [PMID: 28764973 DOI: 10.1016/j.humpath.2017.07.012] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/20/2017] [Revised: 07/06/2017] [Accepted: 07/14/2017] [Indexed: 01/28/2023]
Abstract
Dilated cardiomyopathy (DCM) leads to disturbed contraction and force transduction, and is associated with substantial mortality in all age groups. Involvement of a disrupted composition of the intercalated disc (ID) has been reported. However, in children, little is established about such subcellular changes during disease, because of the pathological mix-up with the ongoing cardiac maturation. This leaves maladaptive remodeling often undetected. We aimed at illustrating subcellular alterations in children diagnosed with DCM compared to age-matched controls, focusing on ID proteins known to be crucially stable under healthy conditions and destabilized during cardiac injury in adults. Left ventricular or septal pediatric specimens were collected from 7 individuals diagnosed with DCM (age: 23 weeks in utero to 8 weeks postnatal) and age-matched controls that died of non-cardiovascular cause. We determined the amount of fibrosis and localization of ID proteins by immunohistochemistry. In pediatric DCM, most ID proteins follow similar spatiotemporal changes in localization as in controls. However, although no mutations were found, the signal of the desmosomal protein Desmoglein-2 was reduced in all pediatric DCM specimens, but not in controls or adult DCM patients. Endocardial and transmural fibrosis was increased in all pediatric DCM patients compared to age-matched controls. Composition of the ID in pediatric DCM patients is similar to controls, except for the localization of Desmoglein-2 and presence of severe fibrosis. This suggests that the architecture of desmosomes is already disturbed in the early stages of DCM. These findings contribute to the understanding of pediatric DCM.
Collapse
Affiliation(s)
- Elise L Kessler
- Department of Medical Physiology, University Medical Center Utrecht, 3584CM Utrecht, The Netherlands
| | - Peter Gj Nikkels
- Department of Pathology, University Medical Center Utrecht, 3584CX Utrecht, The Netherlands
| | - Toon Ab van Veen
- Department of Medical Physiology, University Medical Center Utrecht, 3584CM Utrecht, The Netherlands.
| |
Collapse
|
18
|
Lange S, Gehmlich K, Lun AS, Blondelle J, Hooper C, Dalton ND, Alvarez EA, Zhang X, Bang ML, Abassi YA, Dos Remedios CG, Peterson KL, Chen J, Ehler E. MLP and CARP are linked to chronic PKCα signalling in dilated cardiomyopathy. Nat Commun 2016; 7:12120. [PMID: 27353086 PMCID: PMC4931343 DOI: 10.1038/ncomms12120] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2015] [Accepted: 05/31/2016] [Indexed: 11/28/2022] Open
Abstract
MLP (muscle LIM protein)-deficient mice count among the first mouse models for dilated cardiomyopathy (DCM), yet the exact role of MLP in cardiac signalling processes is still enigmatic. Elevated PKCα signalling activity is known to be an important contributor to heart failure. Here we show that MLP directly inhibits the activity of PKCα. In end-stage DCM, PKCα is concentrated at the intercalated disc of cardiomyocytes, where it is sequestered by the adaptor protein CARP in a multiprotein complex together with PLCβ1. In mice deficient for both MLP and CARP the chronic PKCα signalling chain at the intercalated disc is broken and they remain healthy. Our results suggest that the main role of MLP in heart lies in the direct inhibition of PKCα and that chronic uninhibited PKCα activity at the intercalated disc in the absence of functional MLP leads to heart failure. Altered function of the muscle LIM protein (MLP) causes dilated cardiomyopathy in mice and humans. Lange et al. explain the molecular role of MLP in the heart by showing that it affects the signalling complex at the intercalated discs of failing hearts that consists of PKCα, PLCβ1 and CARP by inhibiting PKCα auto-phosphorylation and function.
Collapse
Affiliation(s)
- Stephan Lange
- School of Medicine, University of California, San Diego, La Jolla CA-92093, USA
| | - Katja Gehmlich
- BHF Centre of Research Excellence Oxford, Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford OX3 9DU, UK
| | - Alexander S Lun
- School of Medicine, University of California, San Diego, La Jolla CA-92093, USA
| | - Jordan Blondelle
- School of Medicine, University of California, San Diego, La Jolla CA-92093, USA
| | - Charlotte Hooper
- BHF Centre of Research Excellence Oxford, Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford OX3 9DU, UK
| | - Nancy D Dalton
- School of Medicine, University of California, San Diego, La Jolla CA-92093, USA
| | - Erika A Alvarez
- School of Medicine, University of California, San Diego, La Jolla CA-92093, USA
| | - Xiaoyu Zhang
- ACEA Biosciences, 6779 Mesa Ridge Rd #100, San Diego, CA-92121, USA
| | - Marie-Louise Bang
- Institute of Genetic and Biomedical Research, UOS Milan, National Research Council, Rozzano (Milan) 20089, Italy.,Humanitas Clinical and Research Center, Rozzano (Milan) 20089, Italy
| | - Yama A Abassi
- ACEA Biosciences, 6779 Mesa Ridge Rd #100, San Diego, CA-92121, USA
| | | | - Kirk L Peterson
- School of Medicine, University of California, San Diego, La Jolla CA-92093, USA
| | - Ju Chen
- School of Medicine, University of California, San Diego, La Jolla CA-92093, USA
| | - Elisabeth Ehler
- BHF Centre of Research Excellence at King's College London, Cardiovascular Division and Randall Division of Cell and Molecular Biophysics, London SE1 1UL, UK
| |
Collapse
|
19
|
Bennett PM, Ehler E, Wilson AJ. Sarcoplasmic reticulum is an intermediary of mitochondrial and myofibrillar growth at the intercalated disc. J Muscle Res Cell Motil 2016; 37:55-69. [PMID: 27329158 PMCID: PMC5010836 DOI: 10.1007/s10974-016-9444-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2016] [Accepted: 05/22/2016] [Indexed: 11/30/2022]
Abstract
In cardiomyocytes columns of intermyofibrillar mitochondria run up to the intercalated disc (ID); half are collinear with those in the neighbouring cell, suggesting coordinated addition of sarcomeres and mitochondria both within and between cells during cardiomyocyte growth. Recent evidence for an association between sarcoplasmic reticulum (SR) and mitochondria indicates that the SR may be an intermediary in this coordinated behaviour. For this reason we have investigated the arrangement of SR and t tubules with respect to mitochondria and myofibrils, particularly at the ID. In the body of the cardiomyocyte the mitochondrial columns are frequently intersected by transverse tubules. In addition, we find that a majority of axial tubules are sandwiched between mitochondria and myofibril. No tubules are found at the ID. SR coats mitochondrial columns and fibrils throughout their length and reaches towards the peaks of the ID membrane where it attaches in the form of junctional (j)SR. These peripheral ID couplings are often situated between mitochondria and ID membrane, suggesting an SR connection between the two. In dilated cardiomyopathy (DCM) the mitochondria are somewhat disordered and clumped. In a mouse model for DCM, the muscle LIM protein KO, we find that there is a lack of mitochondria near the ID, suggesting the uncoupling of the myofibril/mitochondria organisation during growth. SR still coats the fibrils and reaches the ID folds in a jSR coupling. Unlike in control tissue, however, loops and long fingers of ID membrane penetrate into the proximal sarcomere suggesting a possible intermediary state in cardiomyocyte growth.
Collapse
Affiliation(s)
- Pauline M Bennett
- Randall Division of Cell and Molecular Biophysics, King's College London, New Hunt's House, Guy's Campus, London, SE1 1UL, UK.
| | - Elisabeth Ehler
- Randall Division of Cell and Molecular Biophysics, King's College London, New Hunt's House, Guy's Campus, London, SE1 1UL, UK
| | - Amanda J Wilson
- Randall Division of Cell and Molecular Biophysics, King's College London, New Hunt's House, Guy's Campus, London, SE1 1UL, UK.,Department of Life Sciences, Sir Ernst Chain Building, Imperial College London, South Kensington Campus, London, SW7 2AZ, UK
| |
Collapse
|
20
|
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.
Collapse
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.
| |
Collapse
|