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Stevens JA, Dobratz TC, Fischer KD, Palmer A, Bourdage K, Wong AJ, Chapoy-Villanueva H, Garry DJ, Liu JC, Kay MW, Kuzmiak-Glancy S, Townsend D. Mechanisms of reduced myocardial energetics of the dystrophic heart. Am J Physiol Heart Circ Physiol 2024; 326:H396-H407. [PMID: 38099842 DOI: 10.1152/ajpheart.00636.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/03/2023] [Revised: 12/07/2023] [Accepted: 12/12/2023] [Indexed: 01/23/2024]
Abstract
Heart disease is a leading cause of death in patients with Duchenne muscular dystrophy (DMD), characterized by the progressive replacement of contractile tissue with scar tissue. Effective therapies for dystrophic cardiomyopathy will require addressing the disease before the onset of fibrosis, however, the mechanisms of the early disease are poorly understood. To understand the pathophysiology of DMD, we perform a detailed functional assessment of cardiac function of the mdx mouse, a model of DMD. These studies use a combination of functional, metabolomic, and spectroscopic approaches to fully characterize the contractile, energetic, and mitochondrial function of beating hearts. Through these innovative approaches, we demonstrate that the dystrophic heart has reduced cardiac reserve and is energetically limited. We show that this limitation does not result from poor delivery of oxygen. Using spectroscopic approaches, we provide evidence that mitochondria in the dystrophic heart have attenuated mitochondrial membrane potential and deficits in the flow of electrons in complex IV of the electron transport chain. These studies provide evidence that poor myocardial energetics precede the onset of significant cardiac fibrosis and likely results from mitochondrial dysfunction centered around complex IV and reduced membrane potential. The multimodal approach used here implicates specific molecular components in the etiology of reduced energetics. Future studies focused on these targets may provide therapies that improve the energetics of the dystrophic heart leading to improved resiliency against damage and preservation of myocardial contractile tissue.NEW & NOTEWORTHY Dystrophic hearts have poor contractile reserve that is associated with a reduction in myocardial energetics. We demonstrate that oxygen delivery does not contribute to the limited energy production of the dystrophic heart even with increased workloads. Cytochrome optical spectroscopy of the contracting heart reveals alterations in complex IV and evidence of depolarized mitochondrial membranes. We show specific alterations in the electron transport chain of the dystrophic heart that may contribute to poor myocardial energetics.
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Affiliation(s)
- Jackie A Stevens
- Department of Integrative Biology and Physiology, Medical School, University of Minnesota, Minneapolis, Minnesota, United States
| | - Tyler C Dobratz
- Department of Integrative Biology and Physiology, Medical School, University of Minnesota, Minneapolis, Minnesota, United States
| | - Kaleb D Fischer
- Department of Integrative Biology and Physiology, Medical School, University of Minnesota, Minneapolis, Minnesota, United States
| | - Alexandria Palmer
- Department of Integrative Biology and Physiology, Medical School, University of Minnesota, Minneapolis, Minnesota, United States
| | - Kira Bourdage
- Department of Integrative Biology and Physiology, Medical School, University of Minnesota, Minneapolis, Minnesota, United States
| | - Anne J Wong
- Department of Integrative Biology and Physiology, Medical School, University of Minnesota, Minneapolis, Minnesota, United States
| | - Hector Chapoy-Villanueva
- Department of Integrative Biology and Physiology, Medical School, University of Minnesota, Minneapolis, Minnesota, United States
- Institute for Obesity Research Tecnologico de Monterrey, Monterrey, Mexico
| | - Daniel J Garry
- Department of Integrative Biology and Physiology, Medical School, University of Minnesota, Minneapolis, Minnesota, United States
- Lillehei Heart Institute, Cardiovascular Division, University of Minnesota, Minneapolis, Minnesota, United States
- Paul and Sheila Muscular Dystrophy Center, University of Minnesota, Minneapolis, Minnesota, United States
| | - Julia C Liu
- Department of Integrative Biology and Physiology, Medical School, University of Minnesota, Minneapolis, Minnesota, United States
| | - Matthew W Kay
- Department of Biomedical Engineering, School of Engineering and Applied Science, George Washington University, Washington, District of Columbia, United States
| | - Sarah Kuzmiak-Glancy
- Department of Kinesiology, School of Public Health, University of Maryland, College Park, Maryland, United States
| | - DeWayne Townsend
- Department of Integrative Biology and Physiology, Medical School, University of Minnesota, Minneapolis, Minnesota, United States
- Lillehei Heart Institute, Cardiovascular Division, University of Minnesota, Minneapolis, Minnesota, United States
- Paul and Sheila Muscular Dystrophy Center, University of Minnesota, Minneapolis, Minnesota, United States
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2
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Yu B, Zhu HD, Shi XL, Chen PP, Sun XM, Xia GY, Fang M, Zhong YX, Tang XL, Zhang T, Pan HT. iTRAQ-based quantitative proteomic analysis of thoracic aortas from adult rats born to preeclamptic dams. Clin Proteomics 2021; 18:22. [PMID: 34418970 PMCID: PMC8379584 DOI: 10.1186/s12014-021-09327-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Accepted: 08/09/2021] [Indexed: 01/04/2023] Open
Abstract
Background Preeclampsia and gestational hypertension can cause vascular function impairment in offspring. In our previous work, we described the protein expression profiles of umbilical artery tissues from patients with preeclampsia. Methods To gain insights into the mechanisms of vascular dysfunction in adult rats born to preeclamptic dams, we analyzed thoracic aorta tissues by using iTRAQ isobaric tags and 2D nano LC-MS/MS. Results By using the iTRAQ method, we analyzed 1825 proteins, of which 106 showed significantly different expression in the thoracic aortic. Ingenuity pathway analysis (IPA) showed that the majority of differentially expressed proteins (DEPs) were associated with cardiovascular function. Further analysis indicated that glucose-6-phosphate dehydrogenase (G6PD), which is inhibited by miR-423-5p and activated by TP53, had the strongest effect on cardiovascular function. The expression of G6PD was upregulated in thoracic aorta tissues, as confirmed by Western blotting. The expression of two other vascular function-related proteins, cysteine- and glycine-rich protein 2 (CSRP2) and tubulin alpha-4 A (TUBA4A), was upregulated, as demonstrated by mass spectrometry (MS). Conclusions Although the results require further functional validation, these data provide novel findings related to vascular function impairment in the adult offspring of preeclamptic mothers. Supplementary Information The online version contains supplementary material available at 10.1186/s12014-021-09327-9.
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Affiliation(s)
- Bin Yu
- Shaoxing Maternity and Child Health Care Hospital, Shaoxing, 312000, China.,Obstetrics and Gynecology Hospital of Shaoxing University, Shaoxing, China
| | - Hong-Dan Zhu
- Shaoxing Maternity and Child Health Care Hospital, Shaoxing, 312000, China.,Obstetrics and Gynecology Hospital of Shaoxing University, Shaoxing, China
| | - Xiao-Liang Shi
- Shaoxing Maternity and Child Health Care Hospital, Shaoxing, 312000, China.,Obstetrics and Gynecology Hospital of Shaoxing University, Shaoxing, China
| | - Pan-Pan Chen
- Obstetrics and Gynecology Hospital of Shaoxing University, Shaoxing, China
| | - Xiang-Mei Sun
- Obstetrics and Gynecology Hospital of Shaoxing University, Shaoxing, China
| | - Gui-Yu Xia
- Shaoxing Maternity and Child Health Care Hospital, Shaoxing, 312000, China.,Obstetrics and Gynecology Hospital of Shaoxing University, Shaoxing, China
| | - Min Fang
- Shaoxing Maternity and Child Health Care Hospital, Shaoxing, 312000, China.,Obstetrics and Gynecology Hospital of Shaoxing University, Shaoxing, China
| | - Yong-Xing Zhong
- Shaoxing Maternity and Child Health Care Hospital, Shaoxing, 312000, China.,Obstetrics and Gynecology Hospital of Shaoxing University, Shaoxing, China
| | - Xiao-Li Tang
- Shaoxing Maternity and Child Health Care Hospital, Shaoxing, 312000, China.,Obstetrics and Gynecology Hospital of Shaoxing University, Shaoxing, China
| | - Tao Zhang
- Shaoxing Maternity and Child Health Care Hospital, Shaoxing, 312000, China. .,Obstetrics and Gynecology Hospital of Shaoxing University, Shaoxing, China.
| | - Hai-Tao Pan
- Shaoxing Maternity and Child Health Care Hospital, Shaoxing, 312000, China. .,Obstetrics and Gynecology Hospital of Shaoxing University, Shaoxing, China.
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3
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Burnicka-Turek O, Broman MT, Steimle JD, Boukens BJ, Petrenko NB, Ikegami K, Nadadur RD, Qiao Y, Arnolds DE, Yang XH, Patel VV, Nobrega MA, Efimov IR, Moskowitz IP. Transcriptional Patterning of the Ventricular Cardiac Conduction System. Circ Res 2020; 127:e94-e106. [PMID: 32290757 PMCID: PMC8328577 DOI: 10.1161/circresaha.118.314460] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
RATIONALE The heartbeat is organized by the cardiac conduction system (CCS), a specialized network of cardiomyocytes. Patterning of the CCS into atrial node versus ventricular conduction system (VCS) components with distinct physiology is essential for the normal heartbeat. Distinct node versus VCS physiology has been recognized for more than a century, but the molecular basis of this regional patterning is not well understood. OBJECTIVE To study the genetic and genomic mechanisms underlying node versus VCS distinction and investigate rhythm consequences of failed VCS patterning. METHODS AND RESULTS Using mouse genetics, we found that the balance between T-box transcriptional activator, Tbx5, and T-box transcriptional repressor, Tbx3, determined the molecular and functional output of VCS myocytes. Adult VCS-specific removal of Tbx5 or overexpression of Tbx3 re-patterned the fast VCS into slow, nodal-like cells based on molecular and functional criteria. In these cases, gene expression profiling showed diminished expression of genes required for VCS-specific fast conduction but maintenance of expression of genes required for nodal slow conduction physiology. Action potentials of Tbx5-deficient VCS myocytes adopted nodal-specific characteristics, including increased action potential duration and cellular automaticity. Removal of Tbx5 in vivo precipitated inappropriate depolarizations in the atrioventricular (His)-bundle associated with lethal ventricular arrhythmias. TBX5 bound and directly activated cis-regulatory elements at fast conduction channel genes required for fast physiological characteristics of the VCS action potential, defining the identity of the adult VCS. CONCLUSIONS The CCS is patterned entirely as a slow, nodal ground state, with a T-box dependent, physiologically dominant, fast conduction network driven specifically in the VCS. Disruption of the fast VCS gene regulatory network allowed nodal physiology to emerge, providing a plausible molecular mechanism for some lethal ventricular arrhythmias.
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Affiliation(s)
- Ozanna Burnicka-Turek
- Department of Pediatrics, University of Chicago, Chicago, IL 60637, USA
- Department of Pathology, University of Chicago, Chicago, IL 60637, USA
- Department of Human Genetics, University of Chicago, Chicago, IL 60637, USA
| | - Michael T. Broman
- Department of Medicine, The University of Chicago, Chicago, IL, 60637, USA
| | - Jeffrey D. Steimle
- Department of Pediatrics, University of Chicago, Chicago, IL 60637, USA
- Department of Pathology, University of Chicago, Chicago, IL 60637, USA
- Department of Human Genetics, University of Chicago, Chicago, IL 60637, USA
| | - Bastiaan J. Boukens
- Department of Biomedical Engineering, George Washington University, Washington, DC 20052, USA
- Department of Medical Biology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Nataliya B. Petrenko
- Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Penn Cardiovascular Institute, Philadelphia, PA 19104, USA
| | - Kohta Ikegami
- Department of Pediatrics, University of Chicago, Chicago, IL 60637, USA
- Department of Pathology, University of Chicago, Chicago, IL 60637, USA
- Department of Human Genetics, University of Chicago, Chicago, IL 60637, USA
| | - Rangarajan D. Nadadur
- Department of Pediatrics, University of Chicago, Chicago, IL 60637, USA
- Department of Pathology, University of Chicago, Chicago, IL 60637, USA
- Department of Human Genetics, University of Chicago, Chicago, IL 60637, USA
| | - Yun Qiao
- Department of Biomedical Engineering, George Washington University, Washington, DC 20052, USA
| | - David E. Arnolds
- Department of Pediatrics, University of Chicago, Chicago, IL 60637, USA
- Department of Pathology, University of Chicago, Chicago, IL 60637, USA
- Department of Human Genetics, University of Chicago, Chicago, IL 60637, USA
| | - Xinan H. Yang
- Department of Pediatrics, University of Chicago, Chicago, IL 60637, USA
- Department of Pathology, University of Chicago, Chicago, IL 60637, USA
- Department of Human Genetics, University of Chicago, Chicago, IL 60637, USA
| | - Vickas V. Patel
- Discovery Medicine, GlaxoSmithKline, Collegeville, PA 19426, USA
| | - Marcelo A. Nobrega
- Department of Human Genetics, University of Chicago, Chicago, IL 60637, USA
| | - Igor R. Efimov
- Department of Biomedical Engineering, George Washington University, Washington, DC 20052, USA
| | - Ivan P. Moskowitz
- Department of Pediatrics, University of Chicago, Chicago, IL 60637, USA
- Department of Pathology, University of Chicago, Chicago, IL 60637, USA
- Department of Human Genetics, University of Chicago, Chicago, IL 60637, USA
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4
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Laforest B, Dai W, Tyan L, Lazarevic S, Shen KM, Gadek M, Broman MT, Weber CR, Moskowitz IP. Atrial fibrillation risk loci interact to modulate Ca2+-dependent atrial rhythm homeostasis. J Clin Invest 2020; 129:4937-4950. [PMID: 31609246 DOI: 10.1172/jci124231] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Accepted: 08/16/2019] [Indexed: 12/30/2022] Open
Abstract
Atrial fibrillation (AF), defined by disorganized atrial cardiac rhythm, is the most prevalent cardiac arrhythmia worldwide. Recent genetic studies have highlighted a major heritable component and identified numerous loci associated with AF risk, including the cardiogenic transcription factor genes TBX5, GATA4, and NKX2-5. We report that Tbx5 and Gata4 interact with opposite signs for atrial rhythm controls compared with cardiac development. Using mouse genetics, we found that AF pathophysiology caused by Tbx5 haploinsufficiency, including atrial arrhythmia susceptibility, prolonged action potential duration, and ectopic cardiomyocyte depolarizations, were all rescued by Gata4 haploinsufficiency. In contrast, Nkx2-5 haploinsufficiency showed no combinatorial effect. The molecular basis of the TBX5/GATA4 interaction included normalization of intra-cardiomyocyte calcium flux and expression of calcium channel genes Atp2a2 and Ryr2. Furthermore, GATA4 and TBX5 showed antagonistic interactions on an Ryr2 enhancer. Atrial rhythm instability caused by Tbx5 haploinsufficiency was rescued by a decreased dose of phospholamban, a sarco/endoplasmic reticulum Ca2+-ATPase inhibitor, consistent with a role for decreased sarcoplasmic reticulum calcium flux in Tbx5-dependent AF susceptibility. This work defines a link between Tbx5 dose, sarcoplasmic reticulum calcium flux, and AF propensity. The unexpected interactions between Tbx5 and Gata4 in atrial rhythm control suggest that evaluating specific interactions between genetic risk loci will be necessary for ascertaining personalized risk from genetic association data.
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Affiliation(s)
| | | | - Leonid Tyan
- Department of Medicine, University of Chicago, Chicago, Illinois, USA
| | | | | | | | - Michael T Broman
- Department of Medicine, University of Chicago, Chicago, Illinois, USA
| | | | - Ivan P Moskowitz
- Department of Pediatrics, Pathology, and Human Genetics.,Department of Pathology, and
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5
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Bhat SS, Ali R, Khanday FA. Syntrophins entangled in cytoskeletal meshwork: Helping to hold it all together. Cell Prolif 2018; 52:e12562. [PMID: 30515904 DOI: 10.1111/cpr.12562] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Revised: 10/23/2018] [Accepted: 11/08/2018] [Indexed: 01/10/2023] Open
Abstract
Syntrophins are a family of 59 kDa peripheral membrane-associated adapter proteins, containing multiple protein-protein and protein-lipid interaction domains. The syntrophin family consists of five isoforms that exhibit specific tissue distribution, distinct sub-cellular localization and unique expression patterns implying their diverse functional roles. These syntrophin isoforms form multiple functional protein complexes and ensure proper localization of signalling proteins and their binding partners to specific membrane domains and provide appropriate spatiotemporal regulation of signalling pathways. Syntrophins consist of two PH domains, a PDZ domain and a conserved SU domain. The PH1 domain is split by the PDZ domain. The PH2 and the SU domain are involved in the interaction between syntrophin and the dystrophin-glycoprotein complex (DGC). Syntrophins recruit various signalling proteins to DGC and link extracellular matrix to internal signalling apparatus via DGC. The different domains of the syntrophin isoforms are responsible for modulation of cytoskeleton. Syntrophins associate with cytoskeletal proteins and lead to various cellular responses by modulating the cytoskeleton. Syntrophins are involved in many physiological processes which involve cytoskeletal reorganization like insulin secretion, blood pressure regulation, myogenesis, cell migration, formation and retraction of focal adhesions. Syntrophins have been implicated in various pathologies like Alzheimer's disease, muscular dystrophy, cancer. Their role in cytoskeletal organization and modulation makes them perfect candidates for further studies in various cancers and other ailments that involve cytoskeletal modulation. The role of syntrophins in cytoskeletal organization and modulation has not yet been comprehensively reviewed till now. This review focuses on syntrophins and highlights their role in cytoskeletal organization, modulation and dynamics via its involvement in different cell signalling networks.
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Affiliation(s)
- Sahar S Bhat
- Division of Biotechnology, Sher-e-Kashmir University of Agricultural Sciences and Technology of Kashmir, Srinagar, India
| | - Roshia Ali
- Department of Biotechnology, University of Kashmir, Srinagar, India.,Department of Biochemistry, University of Kashmir, Srinagar, India
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6
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100-fold but not 50-fold dystrophin overexpression aggravates electrocardiographic defects in the mdx model of Duchenne muscular dystrophy. MOLECULAR THERAPY-METHODS & CLINICAL DEVELOPMENT 2016; 3:16045. [PMID: 27419194 PMCID: PMC4934459 DOI: 10.1038/mtm.2016.45] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/10/2016] [Revised: 05/17/2016] [Accepted: 05/18/2016] [Indexed: 12/18/2022]
Abstract
Dystrophin gene replacement holds the promise of treating Duchenne muscular dystrophy. Supraphysiological expression is a concern for all gene therapy studies. In the case of Duchenne muscular dystrophy, Chamberlain and colleagues found that 50-fold overexpression did not cause deleterious side effect in skeletal muscle. To determine whether excessive dystrophin expression in the heart is safe, we studied two lines of transgenic mdx mice that selectively expressed a therapeutic minidystrophin gene in the heart at 50-fold and 100-fold of the normal levels. In the line with 50-fold overexpression, minidystrophin showed sarcolemmal localization and electrocardiogram abnormalities were corrected. However, in the line with 100-fold overexpression, we not only detected sarcolemmal minidystrophin expression but also observed accumulation of minidystrophin vesicles in the sarcoplasm. Excessive minidystrophin expression did not correct tachycardia, a characteristic feature of Duchenne muscular dystrophy. Importantly, several electrocardiogram parameters (QT interval, QRS duration and the cardiomyopathy index) became worse than that of mdx mice. Our data suggests that the mouse heart can tolerate 50-fold minidystrophin overexpression, but 100-fold overexpression leads to cardiac toxicity.
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7
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Cingolani E, Ionta V, Cheng K, Giacomello A, Cho HC, Marbán E. Engineered electrical conduction tract restores conduction in complete heart block: from in vitro to in vivo proof of concept. J Am Coll Cardiol 2015; 64:2575-2585. [PMID: 25524335 DOI: 10.1016/j.jacc.2014.09.056] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/29/2014] [Revised: 08/27/2014] [Accepted: 09/16/2014] [Indexed: 12/31/2022]
Abstract
BACKGROUND Cardiac electrical conduction delays and blocks cause rhythm disturbances such as complete heart block, which can be fatal. Standard of care relies on electronic devices to artificially restore synchrony. We sought to create a new modality for treating these disorders by engineering electrical conduction tracts designed to propagate electrical impulses. OBJECTIVES This study sought to create a new approach for treating cardiac conduction disorders by using engineered electrical conduction tracts (EECTs). METHODS Paramagnetic beads were conjugated with an antibody to gamma-sarcoglycan, a cardiomyocyte cell surface antigen, and mixed with freshly isolated neonatal rat ventricular cardiomyocytes. A magnetic field was used to pattern a linear EECT. RESULTS In an in vitro model of conduction block, the EECT was patterned so that it connected 2 independently beating neonatal rat ventricular cardiomyocyte monolayers; it achieved coordinated electrical activity, with action potentials propagating from 1 region to the other via EECT. Spiking the EECT with heart-derived stromal cells yielded stable structures with highly reproducible conduction velocities. Transplantation of EECTs in vivo restored atrioventricular conduction in a rat model of complete heart block. CONCLUSIONS An EECT can re-establish electrical conduction in the heart. This novel approach could, in principle, be used not only to treat cardiac arrhythmias but also to repair other organs.
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Affiliation(s)
| | - Vittoria Ionta
- Cedars-Sinai Heart Institute, Los Angeles, California; University of Rome "La Sapienza," Rome, Italy
| | - Ke Cheng
- Cedars-Sinai Heart Institute, Los Angeles, California
| | | | - Hee Cheol Cho
- Cedars-Sinai Heart Institute, Los Angeles, California.
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8
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Muscle fatigue, nNOS and muscle fiber atrophy in limb girdle muscular dystrophy. ACTA MYOLOGICA : MYOPATHIES AND CARDIOMYOPATHIES : OFFICIAL JOURNAL OF THE MEDITERRANEAN SOCIETY OF MYOLOGY 2014; 33:119-26. [PMID: 25873780 PMCID: PMC4369848] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Muscle fatigability and atrophy are frequent clinical signs in limb girdle muscular dystrophy (LGMD), but their pathogenetic mechanisms are still poorly understood. We review a series of different factors that may be connected in causing fatigue and atrophy, particularly considering the role of neuronal nitric oxide synthase (nNOS) and additional factors such as gender in different forms of LGMD (both recessive and dominant) underlying different pathogenetic mechanisms. In sarcoglycanopathies, the sarcolemmal nNOS reactivity varied from absent to reduced, depending on the residual level of sarcoglycan complex: in cases with complete sarcoglycan complex deficiency (mostly in beta-sarcoglycanopathy), the sarcolemmal nNOS reaction was absent and it was always associated with early severe clinical phenotype and cardiomyopathy. Calpainopathy, dysferlinopathy, and caveolinopathy present gradual onset of fatigability and had normal sarcolemmal nNOS reactivity. Notably, as compared with caveolinopathy and sarcoglycanopathies, calpainopathy and dysferlinopathy showed a higher degree of muscle fiber atrophy. Males with calpainopathy and dysferlinopathy showed significantly higher fiber atrophy than control males, whereas female patients have similar values than female controls, suggesting a gender difference in muscle fiber atrophy with a relative protection in females. In female patients, the smaller initial muscle fiber size associated to endocrine factors and less physical effort might attenuate gender-specific muscle loss and atrophy.
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9
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Greally E, Davison BJ, Blain A, Laval S, Blamire A, Straub V, MacGowan GA. Heterogeneous abnormalities of in-vivo left ventricular calcium influx and function in mouse models of muscular dystrophy cardiomyopathy. J Cardiovasc Magn Reson 2013; 15:4. [PMID: 23324314 PMCID: PMC3564732 DOI: 10.1186/1532-429x-15-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2012] [Accepted: 12/14/2012] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND Manganese-enhanced cardiovascular magnetic resonance (MECMR) can non-invasively assess myocardial calcium influx, and calcium levels are known to be elevated in muscular dystrophy cardiomyopathy based on cellular studies. METHODS Left ventricular functional studies and MECMR were performed in mdx mice (model of Duchenne muscular dystrophy, 24 and 40 weeks) and Sgcd -/- mice (limb girdle muscular dystrophy 2 F, 16 and 32 weeks), compared to wild type controls (C57Bl/10, WT). RESULTS Both models had left ventricular hypertrophy at the later age compared to WT, though the mdx mice had reduced stroke volumes and the Sgcd -/- mice increased heart rate and cardiac index. Especially at the younger ages, MECMR was significantly elevated in both models (both P < 0.05 versus WT). The L-type calcium channel inhibitor diltiazem (5 mg/kg i.p.) significantly reduced MECMR in the mdx mice (P < 0.01), though only with a higher dose (10 mg/kg i.p.) in the Sgcd -/- mice (P < 0.05). As the Sgcd -/- mice had increased heart rates, to determine the role of heart rate in MECMR we studied the hyperpolarization-activated cyclic nucleotide-gated channel inhibitor ZD 7288 which selectively reduces heart rate. This reduced heart rate and MECMR in all mouse groups. However, when looking at the time course of reduction of MECMR in the Sgcd -/- mice at up to 5 minutes of the manganese infusion when heart rates were matched to the WT mice, MECMR was still significantly elevated in the Sgcd -/- mice (P < 0.01) indicating that heart rate alone could not account for all the increased MECMR. CONCLUSIONS Despite both mouse models exhibiting increased in-vivo calcium influx at an early stage in the development of the cardiomyopathy before left ventricular hypertrophy, there are distinct phenotypical differences between the 2 models in terms of heart rates, hemodynamics and responses to calcium channel inhibitors.
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MESH Headings
- Age Factors
- Animals
- Calcium Channel Blockers/pharmacology
- Calcium Channels, L-Type/drug effects
- Calcium Channels, L-Type/metabolism
- Calcium Signaling/drug effects
- Cardiomyopathies/genetics
- Cardiomyopathies/metabolism
- Cardiomyopathies/pathology
- Cardiomyopathies/physiopathology
- Chlorides
- Contrast Media
- Disease Models, Animal
- Disease Progression
- Genotype
- Heart Rate
- Hypertrophy, Left Ventricular/metabolism
- Hypertrophy, Left Ventricular/pathology
- Hypertrophy, Left Ventricular/physiopathology
- Magnetic Resonance Imaging
- Male
- Manganese Compounds
- Mice
- Mice, Inbred mdx
- Mice, Knockout
- Muscular Dystrophy, Duchenne/genetics
- Muscular Dystrophy, Duchenne/metabolism
- Muscular Dystrophy, Duchenne/pathology
- Muscular Dystrophy, Duchenne/physiopathology
- Myocardium/metabolism
- Myocardium/pathology
- Phenotype
- Sarcoglycans/deficiency
- Sarcoglycans/genetics
- Stroke Volume
- Time Factors
- Ventricular Function, Left/drug effects
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Affiliation(s)
- Elizabeth Greally
- Institute of Genetic Medicine, Newcastle University, International Center for Life, Newcastle, UK
| | - Benjamin J Davison
- Institute of Genetic Medicine, Newcastle University, International Center for Life, Newcastle, UK
| | - Alison Blain
- Institute of Genetic Medicine, Newcastle University, International Center for Life, Newcastle, UK
| | - Steve Laval
- Institute of Genetic Medicine, Newcastle University, International Center for Life, Newcastle, UK
| | | | - Volker Straub
- Institute of Genetic Medicine, Newcastle University, International Center for Life, Newcastle, UK
| | - Guy A MacGowan
- Institute of Genetic Medicine, Newcastle University, International Center for Life, Newcastle, UK
- Dept of Cardiology, Freeman Hospital and Newcastle University, Newcastle upon Tyne, NE7 7DN, UK
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10
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Arnolds DE, Liu F, Fahrenbach JP, Kim GH, Schillinger KJ, Smemo S, McNally EM, Nobrega MA, Patel VV, Moskowitz IP. TBX5 drives Scn5a expression to regulate cardiac conduction system function. J Clin Invest 2012; 122:2509-18. [PMID: 22728936 PMCID: PMC3386825 DOI: 10.1172/jci62617] [Citation(s) in RCA: 106] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2011] [Accepted: 05/17/2012] [Indexed: 11/17/2022] Open
Abstract
Cardiac conduction system (CCS) disease, which results in disrupted conduction and impaired cardiac rhythm, is common with significant morbidity and mortality. Current treatment options are limited, and rational efforts to develop cell-based and regenerative therapies require knowledge of the molecular networks that establish and maintain CCS function. Recent genome-wide association studies (GWAS) have identified numerous loci associated with adult human CCS function, including TBX5 and SCN5A. We hypothesized that TBX5, a critical developmental transcription factor, regulates transcriptional networks required for mature CCS function. We found that deletion of Tbx5 from the mature murine ventricular conduction system (VCS), including the AV bundle and bundle branches, resulted in severe VCS functional consequences, including loss of fast conduction, arrhythmias, and sudden death. Ventricular contractile function and the VCS fate map remained unchanged in VCS-specific Tbx5 knockouts. However, key mediators of fast conduction, including Nav1.5, which is encoded by Scn5a, and connexin 40 (Cx40), demonstrated Tbx5-dependent expression in the VCS. We identified a TBX5-responsive enhancer downstream of Scn5a sufficient to drive VCS expression in vivo, dependent on canonical T-box binding sites. Our results establish a direct molecular link between Tbx5 and Scn5a and elucidate a hierarchy between human GWAS loci that affects function of the mature VCS, establishing a paradigm for understanding the molecular pathology of CCS disease.
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Affiliation(s)
- David E Arnolds
- Department of Pediatrics, University of Chicago, Chicago, IL, USA
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11
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Rauch U, Shami A, Zhang F, Carmignac V, Durbeej M, Hultgårdh-Nilsson A. Increased neointimal thickening in dystrophin-deficient mdx mice. PLoS One 2012; 7:e29904. [PMID: 22238670 PMCID: PMC3251593 DOI: 10.1371/journal.pone.0029904] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2011] [Accepted: 12/08/2011] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND The dystrophin gene, which is mutated in Duchenne muscular dystrophy (DMD), encodes a large cytoskeletal protein present in muscle fibers. While dystrophin in skeletal muscle has been extensively studied, the function of dystrophin in vascular smooth muscle is less clear. Here, we have analyzed the role of dystrophin in injury-induced arterial neointima formation. METHODOLOGY/PRINCIPAL FINDINGS We detected a down-regulation of dystrophin, dystroglycan and β-sarcoglycan mRNA expression when vascular smooth muscle cells de-differentiate in vitro. To further mimic development of intimal lesions, we performed a collar-induced injury of the carotid artery in the mdx mouse, a model for DMD. As compared with control mice, mdx mice develop larger lesions with increased numbers of proliferating cells. In vitro experiments demonstrate increased migration of vascular smooth muscle cells from mdx mice whereas the rate of proliferation was similar in cells isolated from wild-type and mdx mice. CONCLUSIONS/SIGNIFICANCE These results show that dystrophin deficiency stimulates neointima formation and suggest that expression of dystrophin in vascular smooth muscle cells may protect the artery wall against injury-induced intimal thickening.
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MESH Headings
- Animals
- Cell Proliferation
- Cells, Cultured
- Dystrophin/deficiency
- Dystrophin/genetics
- Dystrophin/metabolism
- Dystrophin/physiology
- Mice
- Mice, Inbred C57BL
- Mice, Inbred mdx
- Muscle, Smooth, Vascular/metabolism
- Muscle, Smooth, Vascular/pathology
- Muscular Dystrophy, Animal/complications
- Muscular Dystrophy, Animal/genetics
- Muscular Dystrophy, Animal/metabolism
- Muscular Dystrophy, Animal/pathology
- Muscular Dystrophy, Duchenne/complications
- Muscular Dystrophy, Duchenne/genetics
- Muscular Dystrophy, Duchenne/metabolism
- Muscular Dystrophy, Duchenne/pathology
- Myocytes, Smooth Muscle/metabolism
- Myocytes, Smooth Muscle/pathology
- Neointima/genetics
- Neointima/metabolism
- Neointima/pathology
- Organ Size
- Up-Regulation
- Vascular System Injuries/genetics
- Vascular System Injuries/metabolism
- Vascular System Injuries/pathology
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Affiliation(s)
- Uwe Rauch
- Department of Experimental Medical Science, Lund University, Lund, Sweden
| | - Annelie Shami
- Department of Experimental Medical Science, Lund University, Lund, Sweden
| | - Feng Zhang
- Department of Experimental Medical Science, Lund University, Lund, Sweden
| | - Virginie Carmignac
- Department of Experimental Medical Science, Lund University, Lund, Sweden
| | - Madeleine Durbeej
- Department of Experimental Medical Science, Lund University, Lund, Sweden
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12
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Blain AM, Straub VW. δ-Sarcoglycan-deficient muscular dystrophy: from discovery to therapeutic approaches. Skelet Muscle 2011; 1:13. [PMID: 21798091 PMCID: PMC3156636 DOI: 10.1186/2044-5040-1-13] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2010] [Accepted: 03/17/2011] [Indexed: 11/10/2022] Open
Abstract
Mutations in the δ-sarcoglycan gene cause limb-girdle muscular dystrophy 2F (LGMD2F), an autosomal recessive disease that causes progressive weakness and wasting of the proximal limb muscles and often has cardiac involvement. Here we review the clinical implications of LGMD2F and discuss the current understanding of the putative mechanisms underlying its pathogenesis. Preclinical research has benefited enormously from various animal models of δ-sarcoglycan deficiency, which have helped researchers to explore therapeutic approaches for both muscular dystrophy and cardiomyopathy.
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Affiliation(s)
- Alison M Blain
- Institute of Genetic Medicine, Newcastle University, International Centre for Life, Central Parkway, Newcastle upon Tyne, NE1 3BZ, UK
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13
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Verhaert D, Richards K, Rafael-Fortney JA, Raman SV. Cardiac involvement in patients with muscular dystrophies: magnetic resonance imaging phenotype and genotypic considerations. Circ Cardiovasc Imaging 2011; 4:67-76. [PMID: 21245364 DOI: 10.1161/circimaging.110.960740] [Citation(s) in RCA: 139] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- David Verhaert
- Davis Heart and Lung Research Institute, Ohio State University, Columbus, Ohio, USA
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14
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Piazza N, Wessells RJ. Drosophila models of cardiac disease. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2011; 100:155-210. [PMID: 21377627 PMCID: PMC3551295 DOI: 10.1016/b978-0-12-384878-9.00005-4] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The fruit fly Drosophila melanogaster has emerged as a useful model for cardiac diseases, both developmental abnormalities and adult functional impairment. Using the tools of both classical and molecular genetics, the study of the developing fly heart has been instrumental in identifying the major signaling events of cardiac field formation, cardiomyocyte specification, and the formation of the functioning heart tube. The larval stage of fly cardiac development has become an important model system for testing isolated preparations of living hearts for the effects of biological and pharmacological compounds on cardiac activity. Meanwhile, the recent development of effective techniques to study adult cardiac performance in the fly has opened new uses for the Drosophila model system. The fly system is now being used to study long-term alterations in adult performance caused by factors such as diet, exercise, and normal aging. The fly is a unique and valuable system for the study of such complex, long-term interactions, as it is the only invertebrate genetic model system with a working heart developmentally homologous to the vertebrate heart. Thus, the fly model combines the advantages of invertebrate genetics (such as large populations, facile molecular genetic techniques, and short lifespan) with physiological measurement techniques that allow meaningful comparisons with data from vertebrate model systems. As such, the fly model is well situated to make important contributions to the understanding of complicated interactions between environmental factors and genetics in the long-term regulation of cardiac performance.
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Affiliation(s)
- Nicole Piazza
- University of Michigan Medical School, Ann Arbor, MI, USA
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15
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Weiss RM, Kerber RE, Jones JK, Stephan CM, Trout CJ, Lindower PD, Staffey KS, Campbell KP, Mathews KD. Exercise-induced left ventricular systolic dysfunction in women heterozygous for dystrophinopathy. J Am Soc Echocardiogr 2010; 23:848-53. [PMID: 20646909 PMCID: PMC3156088 DOI: 10.1016/j.echo.2010.05.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/31/2009] [Indexed: 01/16/2023]
Abstract
BACKGROUND Mutations in the X-linked gene encoding dystrophin cause skeletal and cardiac muscle diseases in men. Female "carriers" also can develop overt disease. The purpose of this study was to ascertain the prevalence of cardiac contractile abnormalities in dystrophinopathy carriers. METHODS Twenty-four dystrophinopathy heterozygotes and 24 normal women each underwent standard exercise stress echocardiography. RESULTS Heterozygotes demonstrated mildly lower left ventricular ejection fractions (LVEFs) at rest compared with controls (0.56 + or - 0.10 vs 0.62 + or - 0.07, P = .02). After exercise, the mean LVEF fell to 0.53 + or - 0.14 in heterozygotes but rose to 0.73 + or - 0.07 in controls (P < .001). Twenty-one of 24 dystrophinopathy heterozygotes demonstrated > or = 1 of the following: abnormal resting LVEF, abnormal LVEF response to exercise, or exercise-induced wall motion abnormality. CONCLUSIONS Women heterozygous for dystrophinopathy demonstrate significant left ventricular systolic dysfunction, which is unmasked by exercise. This finding has mechanistic implications for both inherited and acquired cardiac disease states.
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Affiliation(s)
- Robert M Weiss
- University of Iowa Hospitals and Clinics, Division of Cardiovascular Medicine, Department of Internal Medicine, 200 Hawkins Drive, Room E317-1 GH, Iowa City, IA 52242, USA.
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16
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Kim H, Pierce-Shimomura JT, Oh HJ, Johnson BE, Goodman MB, McIntire SL. The dystrophin complex controls bk channel localization and muscle activity in Caenorhabditis elegans. PLoS Genet 2009; 5:e1000780. [PMID: 20019812 PMCID: PMC2788698 DOI: 10.1371/journal.pgen.1000780] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2009] [Accepted: 11/19/2009] [Indexed: 01/05/2023] Open
Abstract
Genetic defects in the dystrophin-associated protein complex (DAPC) are responsible for a variety of pathological conditions including muscular dystrophy, cardiomyopathy, and vasospasm. Conserved DAPC components from humans to Caenorhabditis elegans suggest a similar molecular function. C. elegans DAPC mutants exhibit a unique locomotory deficit resulting from prolonged muscle excitation and contraction. Here we show that the C. elegans DAPC is essential for proper localization of SLO-1, the large conductance, voltage-, and calcium-dependent potassium (BK) channel, which conducts a major outward rectifying current in muscle under the normal physiological condition. Through analysis of mutants with the same phenotype as the DAPC mutants, we identified the novel islo-1 gene that encodes a protein with two predicted transmembrane domains. We demonstrate that ISLO-1 acts as a novel adapter molecule that links the DAPC to SLO-1 in muscle. We show that a defect in either the DAPC or ISLO-1 disrupts normal SLO-1 localization in muscle. Consistent with observations that SLO-1 requires a high calcium concentration for full activation, we find that SLO-1 is localized near L-type calcium channels in muscle, thereby providing a mechanism coupling calcium influx with the outward rectifying current. Our results indicate that the DAPC modulates muscle excitability by localizing the SLO-1 channel to calcium-rich regions of C. elegans muscle. Dystrophin is a long rod-shaped protein that forms a complex with several membrane and cytoplasmic proteins in muscle. Genetic defects in components of this dystrophin complex are responsible for many forms of muscular dystrophy, including Duchenne muscular dystrophy. C. elegans possesses the dystrophin complex and mutations in its components cause muscular defects, indicating that the dystrophin complex has an evolutionary conserved role in muscle. Accumulating evidence in mammals indicates that dystrophic muscle exhibits an abnormal calcium homeostasis. It is not clear how defects in the dystrophin complex are linked to calcium homeostasis, however. In a C. elegans genetic study we found that a novel adaptor protein links the dystrophin complex to a calcium-sensitive potassium channel that mediates muscle inactivation. We further demonstrated that both the dystrophin complex and the adaptor protein localize the potassium channel in a close proximity to a muscle-activating calcium channel. This arrangement ensures that calcium increases accompanied by muscle activation are coupled to muscle inactivation. Defects in the dystrophin complex or the adaptor disrupt the localization of the potassium channel, thereby resulting in prolonged muscle activation and calcium ion increases. Our study provides a mechanism by which the dystrophin complex regulates cellular signaling and muscle excitability.
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Affiliation(s)
- Hongkyun Kim
- Department of Cell Biology and Anatomy, The Chicago Medical School, Rosalind Franklin University of Science and Medicine, North Chicago, Illinois, United States of America
- Ernest Gallo Clinic and Research Center, Department of Neurology, University of California San Francisco, Emeryville, California, United States of America
- * E-mail: (HK); (SLM)
| | - Jonathan T. Pierce-Shimomura
- Ernest Gallo Clinic and Research Center, Department of Neurology, University of California San Francisco, Emeryville, California, United States of America
| | - Hyun J. Oh
- Department of Cell Biology and Anatomy, The Chicago Medical School, Rosalind Franklin University of Science and Medicine, North Chicago, Illinois, United States of America
| | - Brandon E. Johnson
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, California, United States of America
| | - Miriam B. Goodman
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, California, United States of America
| | - Steven L. McIntire
- Ernest Gallo Clinic and Research Center, Department of Neurology, University of California San Francisco, Emeryville, California, United States of America
- * E-mail: (HK); (SLM)
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17
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Michele DE, Kabaeva Z, Davis SL, Weiss RM, Campbell KP. Dystroglycan matrix receptor function in cardiac myocytes is important for limiting activity-induced myocardial damage. Circ Res 2009; 105:984-93. [PMID: 19797173 DOI: 10.1161/circresaha.109.199489] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
RATIONALE Genetic mutations in a number of putative glycosyltransferases lead to the loss of glycosylation of dystroglycan and loss of its laminin-binding activity in genetic forms of human muscular dystrophy. Human patients and glycosylation defective myd mice develop cardiomyopathy with loss of dystroglycan matrix receptor function in both striated and smooth muscle. OBJECTIVE To determine the functional role of dystroglycan in cardiac muscle and smooth muscle in the development of cardiomyopathy in muscular dystrophies. METHODS AND RESULTS Using cre/lox-mediated gene targeting, we show here that loss of dystroglycan function in ventricular cardiac myocytes is sufficient to induce a progressive cardiomyopathy in mice characterized by focal cardiac fibrosis, increase in cardiac mass, and dilatation ultimately leading to heart failure. In contrast, disruption of dystroglycan in smooth muscle is not sufficient to induce cardiomyopathy. The specific loss of dystroglycan function in cardiac myocytes causes the accumulation of large, clustered patches of myocytes with membrane damage, which increase in number in response to exercise-induced cardiac stress, whereas exercised mice with normal dystroglycan expression accumulate membrane damage limited to individual myocytes. CONCLUSIONS Our findings suggest dystroglycan function as an extracellular matrix receptor in cardiac myocytes plays a primary role in limiting myocardial damage from spreading to neighboring cardiac myocytes, and loss of dystroglycan matrix receptor function in cardiac muscle cells is likely important in the development of cardiomyopathy in glycosylation-deficient muscular dystrophies.
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Affiliation(s)
- Daniel E Michele
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI 48109-0622, USA.
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18
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Missihoun C, Zisa D, Shabbir A, Lin H, Lee T. Myocardial oxidative stress, osteogenic phenotype, and energy metabolism are differentially involved in the initiation and early progression of delta-sarcoglycan-null cardiomyopathy. Mol Cell Biochem 2008; 321:45-52. [PMID: 18726675 DOI: 10.1007/s11010-008-9908-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2008] [Accepted: 08/19/2008] [Indexed: 12/11/2022]
Abstract
Dilated cardiomyopathy (DCM) is a common cause of heart failure, and identification of early pathogenic events occurring prior to the onset of cardiac dysfunction is of mechanistic, diagnostic, and therapeutic importance. The work characterized early biochemical pathogenesis in TO2 strain hamsters lacking delta-sarcoglycan. Although the TO2 hamster heart exhibits normal function at 1 month of age (presymptomatic stage), elevated levels of myeloperoxidase, monocyte chemotactic protein-1, malondialdehyde, osteopontin, and alkaline phosphatase were evident, indicating the presence of inflammation, oxidative stress, and osteogenic phenotype. These changes were localized primarily to the myocardium. Derangement in energy metabolism was identified at the symptomatic stage (4 month), and is marked by attenuated activity and expression of pyruvate dehydrogenase E1 subunit, which catalyzes the rate-limiting step in aerobic glucose metabolism. Thus, this study illustrates differential involvement of oxidative stress, osteogenic phenotype, and glucose metabolism in the initiation and early progression of delta-sarcoglycan-null DCM.
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Affiliation(s)
- Comlan Missihoun
- Department of Biochemistry and Center for Research in Cardiovascular Medicine, University at Buffalo, Buffalo, NY 14214, USA
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19
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Lipskaia L, Pinet C, Fromes Y, Hatem S, Cantaloube I, Coulombe A, Lompré AM. Mutation of delta-sarcoglycan is associated with Ca(2+) -dependent vascular remodeling in the Syrian hamster. THE AMERICAN JOURNAL OF PATHOLOGY 2007; 171:162-71. [PMID: 17591963 PMCID: PMC1941595 DOI: 10.2353/ajpath.2007.070054] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
We examined whether mutation of the delta-sarcoglycan gene, which causes dilated cardiomyopathy, also alters the vascular smooth muscle cell (VSMC) phenotype and arterial function in the Syrian hamster CHF 147. Thoracic aorta media thickness showed marked variability in diseased hamsters with zones of atrophy and hypertrophied segments. CHF-147 VSMCs displayed a proliferating/"synthetic" phenotype characterized by the absence of the smooth muscle myosin heavy chain SM2, dystrophin, and Ca(2+)-handling proteins, and the presence of cyclin D1. In freshly isolated VSMCs from CHF 147 hamsters, voltage-independent basal Ca(2+) channels showed enhanced activity similar to that in proliferating wild-type (WT) cells. The transcription factor NFAT (nuclear factor of activated T cells) was spontaneously active in freshly isolated CHF 147 VSMCs, as in proliferating VSMCs from WT hamsters. Mibefradil inhibited B-type channels, NFAT activity, and VSMC proliferation. CHF 147 hamsters had abundant apoptotic cells distributed in patches along the aorta, and clusters of inactive mitochondria were observed in 25% of isolated CHF 147 cells, whereas no such clusters were seen in WT cells. In conclusion, mutation of the delta-sarcoglycan gene increases plasma membrane permeability to Ca(2+), activates the Ca(2+)-regulated transcription factor NFAT, and leads to spontaneous mitochondrial aggregation, causing abnormal VSMC proliferation and apoptosis.
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Affiliation(s)
- Larissa Lipskaia
- INSERM UMR S621, 91 bd de l'Hôpital, 75634 Paris Cedex 13, France
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20
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Duan D. Challenges and opportunities in dystrophin-deficient cardiomyopathy gene therapy. Hum Mol Genet 2006; 15 Spec No 2:R253-61. [PMID: 16987891 PMCID: PMC2581718 DOI: 10.1093/hmg/ddl180] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
The last decade has evidenced unprecedented progress in gene therapy of Duchenne and Becker muscular dystrophy (DMD and BMD) skeletal muscle disease. Cardiomyopathy is a leading cause of morbidity and mortality in both patients and carriers of DMD, BMD and X-linked dilated cardiomyopathy. However, there is little advance in heart gene therapy. The gene, the vector, vector delivery, the target tissue and animal models are five fundamental components in developing an effective gene therapy. Intensive effort has been made in optimizing gene transfer vectors and methods. Systemic and/or local delivery of recombinant adeno-associated viral vector have resulted in widespread transduction in the rodent heart. The current challenge is to define other parameters that are essential for a successful gene therapy such as the best candidate gene(s), the optimal expression level and the target tissue. This review focuses on these long-ignored aspects and points out future research directions. In particular, we need to address whether all or only some of the recently developed mini- and microgenes are protective in the heart, whether partial correction can lead to whole heart function improvement, whether over-expression is hazardous and whether correcting skeletal muscle disease can slow down or stop the progression of cardiomyopathy. Discussion is also made on whether the current mouse models can meet these research needs.
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Affiliation(s)
- Dongsheng Duan
- Department of Molecular Microbiology and Immunology, The University of Missouri School of Medicine, One Hospital Dr., Room M610G, MSB Columbia, MO 65212, USA.
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21
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Miyata S, Takemura G, Kawase Y, Li Y, Okada H, Maruyama R, Ushikoshi H, Esaki M, Kanamori H, Li L, Misao Y, Tezuka A, Toyo-Oka T, Minatoguchi S, Fujiwara T, Fujiwara H. Autophagic cardiomyocyte death in cardiomyopathic hamsters and its prevention by granulocyte colony-stimulating factor. THE AMERICAN JOURNAL OF PATHOLOGY 2006; 168:386-97. [PMID: 16436654 PMCID: PMC1606501 DOI: 10.2353/ajpath.2006.050137] [Citation(s) in RCA: 98] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
In UM-X7.1 hamster model of human dilated cardiomyopathy, heart failure progressively develops and causes 50% mortality by 30 weeks of age. Through ultrastructural analysis, we found that many cardiomyocytes of this model contain typical autophagic vacuoles including degraded mitochondria, glycogen granules, and myelin-like figures. In addition, ubiquitin, cathepsin D, and Rab7 were overexpressed as determined by immunoassays. Importantly, most cardiomyocytes with leaky plasma membranes were positive for cathepsin D, suggesting a direct link between autophagic degeneration and cell death. Meanwhile, cardiomyocyte apoptosis appeared insignificant. Granulocyte colony-stimulating factor (10 microg/kg/day), injected 5 days/week from 15 to 30 weeks of age, improved survival among 30-week-old hamsters (100% versus 53% in the untreated hamsters, P < 0.0001); ventricular function and remodeling, increased cardiomyocyte size, and reduced myocardial fibrosis followed by a dramatic reduction in the autophagic findings were also seen. Granulocyte colony-stimulating factor also down-regulated tumor necrosis factor-alpha and increased activities of Akt signal transducer and activator of transcription-3, and matrix metalloproteinases. However, there was no clear evidence of transdifferentiation from bone marrow cells into cardiomyocytes. In conclusion, autophagic death is important for cardiomyocyte loss in the cardiomyopathic hamster, and the beneficial effect of granulocyte colony-stimulating factor acts mainly via an anti-autophagic mechanism rather than anti-apo-ptosis or regeneration.
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Affiliation(s)
- Shusaku Miyata
- Second Department of Internal Medicine, Gifu University School of Medicine, 1-1 Yanagido, Gifu 501-1194, Japan
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22
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Wolf MJ, Amrein H, Izatt JA, Choma MA, Reedy MC, Rockman HA. Drosophila as a model for the identification of genes causing adult human heart disease. Proc Natl Acad Sci U S A 2006; 103:1394-9. [PMID: 16432241 PMCID: PMC1360529 DOI: 10.1073/pnas.0507359103] [Citation(s) in RCA: 173] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Drosophila melanogaster genetics provides the advantage of molecularly defined P-element insertions and deletions that span the entire genome. Although Drosophila has been extensively used as a model system to study heart development, it has not been used to dissect the genetics of adult human heart disease because of an inability to phenotype the adult fly heart in vivo. Here we report the development of a strategy to measure cardiac function in awake adult Drosophila that opens the field of Drosophila genetics to the study of human dilated cardiomyopathies. Through the application of optical coherence tomography, we accurately distinguish between normal and abnormal cardiac function based on measurements of internal cardiac chamber dimensions in vivo. Normal Drosophila have a fractional shortening of 87 +/- 4%, whereas cardiomyopathic flies that contain a mutation in troponin I or tropomyosin show severe impairment of systolic function. To determine whether the fly can be used as a model system to recapitulate human dilated cardiomyopathy, we generated transgenic Drosophila with inducible cardiac expression of a mutant of human delta-sarcoglycan (deltasg(S151A)), which has previously been associated with familial dilated cardiomyopathy. Compared to transgenic flies overexpressing wild-type deltasg, or the standard laboratory strain w(1118), Drosophila expressing deltasg(S151A) developed marked impairment of systolic function and significantly enlarged cardiac chambers. These data illustrate the utility of Drosophila as a model system to study dilated cardiomyopathy and the applicability of the vast genetic resources available in Drosophila to systematically study the genetic mechanisms responsible for human cardiac disease.
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Affiliation(s)
- Matthew J Wolf
- Department of Medicine, Duke University, Durham, NC 27110, USA
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23
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Abstract
Factors that render patients with cardiovascular disease at high risk for heart failure remain incompletely defined. Recent insights into molecular genetic causes of myocardial diseases have highlighted the importance of single-gene defects in the pathogenesis of heart failure. Through analyses of the mechanisms by which a mutation selectively perturbs one component of cardiac physiology and triggers cell and molecular responses, studies of human gene mutations provide a window into the complex processes of cardiac remodeling and heart failure. Knowledge gleaned from these studies shows promise for defining novel therapeutic targets for genetic and acquired causes of heart failure.
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Affiliation(s)
- Hiroyuki Morita
- Department of Genetics, Harvard Medical School, Division of Cardiology, Brigham and Women's Hospital, and Howard Hughes Medical Institute, Boston, Massachusetts 02115, USA
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24
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Abstract
Factors that render patients with cardiovascular disease at high risk for heart failure remain incompletely defined. Recent insights into molecular genetic causes of myocardial diseases have highlighted the importance of single-gene defects in the pathogenesis of heart failure. Through analyses of the mechanisms by which a mutation selectively perturbs one component of cardiac physiology and triggers cell and molecular responses, studies of human gene mutations provide a window into the complex processes of cardiac remodeling and heart failure. Knowledge gleaned from these studies shows promise for defining novel therapeutic targets for genetic and acquired causes of heart failure.
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Affiliation(s)
- Hiroyuki Morita
- Department of Genetics, Harvard Medical School, Division of Cardiology, Brigham and Women's Hospital, and Howard Hughes Medical Institute, Boston, Massachusetts 02115, USA
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25
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Lapidos KA, Chen YE, Earley JU, Heydemann A, Huber JM, Chien M, Ma A, McNally EM. Transplanted hematopoietic stem cells demonstrate impaired sarcoglycan expression after engraftment into cardiac and skeletal muscle. J Clin Invest 2005; 114:1577-85. [PMID: 15578090 PMCID: PMC529287 DOI: 10.1172/jci23071] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2004] [Accepted: 09/28/2004] [Indexed: 11/17/2022] Open
Abstract
Pluripotent bone marrow-derived side population (BM-SP) stem cells have been shown to repopulate the hematopoietic system and to contribute to skeletal and cardiac muscle regeneration after transplantation. We tested BM-SP cells for their ability to regenerate heart and skeletal muscle using a model of cardiomyopathy and muscular dystrophy that lacks delta-sarcoglycan. The absence of delta-sarcoglycan produces microinfarcts in heart and skeletal muscle that should recruit regenerative stem cells. Additionally, sarcoglycan expression after transplantation should mark successful stem cell maturation into cardiac and skeletal muscle lineages. BM-SP cells from normal male mice were transplanted into female delta-sarcoglycan-null mice. We detected engraftment of donor-derived stem cells into skeletal muscle, with the majority of donor-derived cells incorporated within myofibers. In the heart, donor-derived nuclei were detected inside cardiomyocytes. Skeletal muscle myofibers containing donor-derived nuclei generally failed to express sarcoglycan, with only 2 sarcoglycan-positive fibers detected in the quadriceps muscle from all 14 mice analyzed. Moreover, all cardiomyocytes with donor-derived nuclei were sarcoglycan-negative. The absence of sarcoglycan expression in cardiomyocytes and skeletal myofibers after transplantation indicates impaired differentiation and/or maturation of bone marrow-derived stem cells. The inability of BM-SP cells to express this protein severely limits their utility for cardiac and skeletal muscle regeneration.
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Affiliation(s)
- Karen A Lapidos
- Department of Molecular Genetics and Cell Biology, University of Chicago, Chicago, Illinois, USA
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