1
|
Gannon MP, Link MS. Phenotypic variation and targeted therapy of hypertrophic cardiomyopathy using genetic animal models. Trends Cardiovasc Med 2019; 31:20-31. [PMID: 31862214 DOI: 10.1016/j.tcm.2019.11.009] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Revised: 10/14/2019] [Accepted: 11/19/2019] [Indexed: 12/25/2022]
Abstract
Hypertrophic cardiomyopathy (HCM) has a variable clinical presentation due to the diversity of causative genetic mutations. Animal models allow in vivo study of genotypic expression through non-invasive imaging, pathologic sampling, and force analysis. This review focuses on the spontaneous and induced mutations in various animal models affecting mainly sarcomere proteins. The sarcomere is comprised of thick (myosin) filaments and related proteins including myosin heavy chain and myosin binding protein-C; thin (actin) filament proteins and their associated regulators including tropomyosin, troponin I, troponin C, and troponin T. The regulatory milieu including transcription factors and cell signaling also play a significant role. Animal models provide a layered approach of understanding beginning with the causative mutation as a foundation. The functional consequences of protein energy utilization and calcium sensitivity in vivo and ex vivo can be studied. Beyond pathophysiologic disruption of sarcomere function, these models demonstrate the clinical sequalae of diastolic dysfunction, heart failure, and arrhythmogenic death. Through this cascade of understanding the mutation followed by their functional significance, targeted therapies have been developed and are briefly discussed.
Collapse
Affiliation(s)
- Michael P Gannon
- National Heart, Lung and Blood Institute, National Institutes of Health, US Department of Health and Human Services, Bldg 10, Rm B1D416, 10 Center Drive, Bethesda, MD 20892, USA.
| | - Mark S Link
- University of Texas Southwestern Medical Center, USA
| |
Collapse
|
2
|
Müller M, Mazur AJ, Behrmann E, Diensthuber RP, Radke MB, Qu Z, Littwitz C, Raunser S, Schoenenberger CA, Manstein DJ, Mannherz HG. Functional characterization of the human α-cardiac actin mutations Y166C and M305L involved in hypertrophic cardiomyopathy. Cell Mol Life Sci 2012; 69:3457-79. [PMID: 22643837 PMCID: PMC11115188 DOI: 10.1007/s00018-012-1030-5] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2011] [Revised: 04/22/2012] [Accepted: 05/07/2012] [Indexed: 11/25/2022]
Abstract
Inherited cardiomyopathies are caused by point mutations in sarcomeric gene products, including α-cardiac muscle actin (ACTC1). We examined the biochemical and cell biological properties of the α-cardiac actin mutations Y166C and M305L identified in hypertrophic cardiomyopathy (HCM). Untagged wild-type (WT) cardiac actin, and the Y166C and M305L mutants were expressed by the baculovirus/Sf9-cell system and affinity purified by immobilized gelsolin G4-6. Their correct folding was verified by a number of assays. The mutant actins also displayed a disturbed intrinsic ATPase activity and an altered polymerization behavior in the presence of tropomyosin, gelsolin, and Arp2/3 complex. Both mutants stimulated the cardiac β-myosin ATPase to only 50 % of WT cardiac F-actin. Copolymers of WT and increasing amounts of the mutant actins led to a reduced stimulation of the myosin ATPase. Transfection of established cell lines revealed incorporation of EGFP- and hemagglutinin (HA)-tagged WT and both mutant actins into cytoplasmic stress fibers. Adenoviral vectors of HA-tagged WT and Y166C actin were successfully used to infect adult and neonatal rat cardiomyocytes (NRCs). The expressed HA-tagged actins were incorporated into the minus-ends of NRC thin filaments, demonstrating the ability to form hybrid thin filaments with endogenous actin. In NRCs, the Y166C mutant led after 72 h to a shortening of the sarcomere length when compared to NRCs infected with WT actin. Thus our data demonstrate that a mutant actin can be integrated into cardiomyocyte thin filaments and by its reduced mode of myosin interaction might be the basis for the initiation of HCM.
Collapse
Affiliation(s)
- Mirco Müller
- Institute for Biophysical Chemistry, OE 4350, Hannover Medical School, 30625 Hannover, Germany
| | - Antonina Joanna Mazur
- Department of Anatomy and Molecular Embryology, Ruhr-University, Universitätsstrasse 150, 44780 Bochum, Germany
- Present Address: Department of Cell Pathology, Faculty of Biotechnology, University of Wroclaw, 51-148 Wroclaw, Poland
| | - Elmar Behrmann
- Department of Physical Biochemistry, Max-Planck-Institute for Molecular Physiology, 44227 Dortmund, Germany
| | - Ralph P. Diensthuber
- Institute for Biophysical Chemistry, OE 4350, Hannover Medical School, 30625 Hannover, Germany
| | - Michael B. Radke
- Institute for Biophysical Chemistry, OE 4350, Hannover Medical School, 30625 Hannover, Germany
| | - Zheng Qu
- Department of Anatomy and Molecular Embryology, Ruhr-University, Universitätsstrasse 150, 44780 Bochum, Germany
| | - Christoph Littwitz
- Department of Physiology, Stritch School of Medicine, Loyola University Chicago, Chicago, USA
| | - Stefan Raunser
- Department of Physical Biochemistry, Max-Planck-Institute for Molecular Physiology, 44227 Dortmund, Germany
| | - Cora-Ann Schoenenberger
- Maurice E. Müller Institute for Structural Biology, Biozentrum, University of Basel, 4046 Basel, Switzerland
| | - Dietmar J. Manstein
- Institute for Biophysical Chemistry, OE 4350, Hannover Medical School, 30625 Hannover, Germany
| | - Hans Georg Mannherz
- Department of Anatomy and Molecular Embryology, Ruhr-University, Universitätsstrasse 150, 44780 Bochum, Germany
- Department of Physical Biochemistry, Max-Planck-Institute for Molecular Physiology, 44227 Dortmund, Germany
| |
Collapse
|
3
|
Yang Q, Sanbe A, Osinska H, Hewett TE, Klevitsky R, Robbins J. A mouse model of myosin binding protein C human familial hypertrophic cardiomyopathy. J Clin Invest 1998; 102:1292-300. [PMID: 9769321 PMCID: PMC508976 DOI: 10.1172/jci3880] [Citation(s) in RCA: 137] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Familial hypertrophic cardiomyopathy can be caused by mutations in genes encoding sarcomeric proteins, including the cardiac isoform of myosin binding protein C (MyBP-C), and multiple mutations which cause truncated forms of the protein to be made are linked to the disease. We have created transgenic mice in which varying amounts of a mutated MyBP-C, lacking the myosin and titin binding domains, are expressed in the heart. The transgenically encoded, truncated protein is stable but is not incorporated efficiently into the sarcomere. The transgenic muscle fibers showed a leftward shift in the pCa2+-force curve and, importantly, their power output was reduced. Additionally, expression of the mutant protein leads to decreased levels of endogenous MyBP-C, resulting in a striking pattern of sarcomere disorganization and dysgenesis.
Collapse
Affiliation(s)
- Q Yang
- Department of Pediatrics, Division of Molecular Cardiovascular Biology, Children's Hospital Research Foundation, Cincinnati, Ohio 45229-3039, USA
| | | | | | | | | | | |
Collapse
|
4
|
Gleichmann U, Seggewiss H. [Clinical picture and therapy of hypertrophic cardiomyopathy]. MEDIZINISCHE KLINIK (MUNICH, GERMANY : 1983) 1998; 93:260-7. [PMID: 9594536 DOI: 10.1007/bf03044802] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Hypertrophic cardiomyopathy is defined as a primary, sometimes familial and genetically fixed myocardial hypertrophy. In the obstructive form of the disease (HOCM) a dynamic outflow tract obstruction of the left, occasionally also the right ventricle can be found. HOCM is the most frequent cause of stress-induced syncope or sudden cardiac death in younger patients. An individual estimation of prognosis is difficult although several risk factors have been identified. In addition to standard therapy of symptomatic patients (medical treatment with betablockers and calcium-antagonists of verapamil-type as well as surgical myotomy/myectomy) DDD-pacemaker implantation and percutaneous transluminal septal myocardial ablation (PTSMA) by alcohol-induced septal branch occlusion have been introduced. After PTSMA significant outflow tract gradient reduction can be achieved in > 90% of patients. Due to remodeling after circumscribed myocardial necrosis further gradient reduction has been observed during follow-up. Optimization of ablated septal area by echocardiographic monitoring resulted in reduction of the most important complication (trifascicular block with need of permanent pacemaker implantation) and improvement of acute and follow-up results. Long-term follow-up and comparison with established treatment options are necessary to evaluate the definitive importance of the promising new treatment.
Collapse
Affiliation(s)
- U Gleichmann
- Kardiologische Klinik, Herz- und Diabeteszentrum NRW, Ruhr-Universität Bochum, Bad Oeynhausen
| | | |
Collapse
|
5
|
Seggewiss H, Gleichmann U, Faber L, Fassbender D, Schmidt HK, Strick S. Percutaneous transluminal septal myocardial ablation in hypertrophic obstructive cardiomyopathy: acute results and 3-month follow-up in 25 patients. J Am Coll Cardiol 1998; 31:252-8. [PMID: 9462563 DOI: 10.1016/s0735-1097(97)00508-1] [Citation(s) in RCA: 170] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
OBJECTIVES We report the acute results and midterm clinical course after percutaneous transluminal septal myocardial ablation (PTSMA) in symptomatic patients with hypertrophic obstructive cardiomyopathy (HOCM). BACKGROUND In the treatment of HOCM, surgical myectomy and DDD pacemaker therapy are considered the standard procedural extensions to drug therapy with negatively inotropic drugs. As an alternative nonsurgical procedure for reducing the left ventricular outflow tract (LVOT) gradient, PTSMA by alcohol-induced septal branch occlusion was introduced. However, clinical follow-up has not been sufficiently described. METHODS In 25 patients (13 women, 12 men; mean [+/- SD] age 54.7 +/- 15.0 years) who were symptomatic despite sufficient drug therapy, 1.4 +/- 0.6 septal branches were occluded with an injection of 4.1 +/- 2.6 ml of alcohol (96%) to ablate the hypertrophied interventricular septum. After 3-months, follow-up results of LVOT gradients and clinical course were determined. RESULTS The invasively determined LVOT gradients could be reduced in 22 patients (88%), with a mean reduction from 61.8 +/- 29.8 mm Hg (range 4 to 152) to 19.4 +/- 20.8 mm Hg (range 0 to 74) at rest (p < 0.0001) and from 141.4 +/- 45.3 mm Hg (range 76 to 240) to 61.1 +/- 40.1 mm Hg (range 0 to 135) after extrasystole. All patients had angina pectoris for 24 h. The maximal creatine kinase increase was 780 +/- 436 U/liter (range 305 to 1,810) after 11.1 +/- 6.0 h (range 4 to 24). Thirteen patients (52%) developed a trifascicular block for 5 min to 8 days requiring temporary (n = 8 [32%]) or permanent (DDD) pacemaker implantation (n = 5 [20%]). An 86-year old woman died 8 days after successful intervention of uncontrollable ventricular fibrillation in conjunction with beta-sympathomimetics in chronically obstructive pulmonary disease. The remaining patients were discharged after 11.3 +/- 5.4 days (range 5 to 24), after an uncomplicated hospital course. Clinical and echocardiographic follow-up was achieved in all 24 surviving patients after 3 months. No cardiac complications occurred. Twenty-one patients (88%) showed clinical improvement, with a New York Heart Association functional class of 1.4 +/- 1.1. A further reduction in LVOT gradient was shown in 14 patients (58%). CONCLUSIONS PTSMA of HOCM is a promising nonsurgical technique for septal myocardial reduction, with a consecutive reduction in LVOT gradient. Possible complications are trifascicular blocks, requiring permanent pacemaker implantation, and tachycardiac rhythm disturbances. Clinical long-term observations of larger patient series and a comparison with conventional forms of therapy are necessary to determine the conclusive therapeutic significance.
Collapse
MESH Headings
- Adult
- Aged
- Aged, 80 and over
- Angina Pectoris/etiology
- Angioplasty, Balloon, Coronary
- Cardiac Complexes, Premature/physiopathology
- Cardiomyopathy, Hypertrophic/drug therapy
- Cardiomyopathy, Hypertrophic/enzymology
- Cardiomyopathy, Hypertrophic/therapy
- Catheter Ablation
- Cause of Death
- Coronary Vessels
- Creatine Kinase/analysis
- Depression, Chemical
- Echocardiography
- Ethanol/adverse effects
- Ethanol/therapeutic use
- Female
- Follow-Up Studies
- Heart Block/etiology
- Heart Block/therapy
- Heart Septum/pathology
- Humans
- Injections, Intra-Arterial
- Lung Diseases, Obstructive/complications
- Male
- Middle Aged
- Myocardial Contraction/drug effects
- Pacemaker, Artificial
- Stroke Volume/physiology
- Sympathomimetics/adverse effects
- Treatment Outcome
- Ventricular Fibrillation/etiology
- Ventricular Function, Left/physiology
Collapse
Affiliation(s)
- H Seggewiss
- Department of Cardiology, Heart and Diabetes Center Nordrhein-Westfalch, University Hospital of the Ruhr University of Bochum, Bad Oeynhausen, Germany.
| | | | | | | | | | | |
Collapse
|
6
|
Ishanov A, Okamoto H, Yoneya K, Watanabe M, Nakagawa I, Machida M, Onozuka H, Mikami T, Kawaguchi H, Hata A, Kondo K, Kitabatake A. Angiotensinogen gene polymorphism in Japanese patients with hypertrophic cardiomyopathy. Am Heart J 1997; 133:184-9. [PMID: 9023164 DOI: 10.1016/s0002-8703(97)70207-2] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
To examine the contribution of the renin-angiotensin system to hypertrophic cardiomyopathy (HCM), we studied 96 patients with HCM (mean age 50 years, 55% male), 105 of their unaffected siblings and offspring, and 160 healthy subjects without known hypertension and left ventricular hypertrophy (LVH) who were frequency matched to cases by age and sex. Patients were divided into familial or sporadic HCM (FHCM or SHCM) groups with or without affected members of their family. The region of interest in the angiotensinogen (AGT) gene, the missense mutation with methione-to-threonine amino acid substitution at codon 235 in angiotensinogen (M235T), was amplified by polymerase chain reaction with the use of allele-specific oligonucleotide primers flanking the polymorphic region of the AGT gene to amplify template deoxyribonucleic acid prepared from peripheral leukocytes. The T allele frequency was higher in the SHCM group than in unaffected siblings and offspring (88% vs 78%, X2 = 4.6, p < 0.05). The M allele frequency was higher in unaffected siblings and offspring than in patients with SHCM (23% vs 12%, X2 = 4.6, p < 0.05). The T allele frequency among unaffected siblings and offspring was similar to that observed in healthy subjects (78% vs 78%). We conclude that HCM, especially in sporadic cases, is partially determined by genetic disposition. The molecular variant of angiotensinogen T235 seems to be a predisposing factor for cardiac hypertrophy in HCM and carries an approximately twofold increased risk.
Collapse
Affiliation(s)
- A Ishanov
- Department of Cardiovascular Medicine, Hokkaido University School of Medicine, Kita-ku, Sapporo, Japan
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
7
|
Watkins H, Seidman CE, Seidman JG, Feng HS, Sweeney HL. Expression and functional assessment of a truncated cardiac troponin T that causes hypertrophic cardiomyopathy. Evidence for a dominant negative action. J Clin Invest 1996; 98:2456-61. [PMID: 8958207 PMCID: PMC507702 DOI: 10.1172/jci119063] [Citation(s) in RCA: 88] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Mutations in the beta-myosin heavy chain gene are believed to cause hypertrophic cardiomyopathy (HCM) by acting as dominant negative alleles. In contrast, a truncated cardiac troponin T (TnT) that causes HCM implies that altered stoichiometry of contractile proteins may also cause cardiac hypertrophy. Wild-type and HCM-mutant (truncated) TnT were studied in a novel quail myotube expression system. Unexpectedly, antibody staining demonstrated incorporation of both forms of human cardiac TnT into the sarcomeres of quail myotubes. Functional studies of wild type and mutant transfected myotubes of normal appearance revealed that calcium-activated force of contraction was normal upon incorporation of wild type TnT, but greatly diminished for the mutant TnT. These findings indicate that HCM-causing mutations in TnT and beta-myosin heavy chain share abnormalities in common, acting as dominant negative alleles that impair contractile performance. This diminished force output is the likely stimulus for hypertrophy in the human heart.
Collapse
Affiliation(s)
- H Watkins
- Department of Cardiovascular Medicine, University of Oxford, United Kingdom
| | | | | | | | | |
Collapse
|
8
|
Abstract
Congenital heart disease (CHD), cardiomyopathy, and vasculopathies are common causes of mortality and morbidity in pediatrics, including the perinatal period. This article reviews evidence that single gene defects cause many of the pediatric heart diseases. Vasculopathies discussed include Marfan's syndrome, supravalvar aortic stenosis and Williams' syndrome, Alagille's syndrome, and hereditary telangiectasia, the Osler-Weber-Rendu syndrome. Genetic causes of hypertrophic cardiomyopathy caused by sarcomeric protein mutations (beta-cardiac myosin heavy chain) and of dilated cardiomyopathy secondary to structural protein deficiencies (dystrophin) are presented. Defects in proteins essential for myocardial energy production such as oxidative phosphorylation proteins and fatty acid oxidation genes that cause cardiomyopathy or sudden death are described. Gene ablation models in mice, such as RXR alpha and homeobox gene knockouts, which result in cardiac phenotypes resembling human congenital heart disease, are described. Familial types of human CHD which are being investigated for genetic causes by positional cloning methods and known cytogenetic causes of CHD, including the CATCH-22 syndrome and monosomy at 22q11, are presented. General lessons and principles derived from these new and exciting discoveries in human cardiovascular development are surmised.
Collapse
Affiliation(s)
- A W Strauss
- Department of Pediatrics, Washington University School of Medicine, St. Louis, MO, USA
| | | |
Collapse
|
9
|
Posma JL, van der Wall EE, Blanksma PK, van der Wall E, Lie KI. New diagnostic options in hypertrophic cardiomyopathy. Am Heart J 1996; 132:1031-41. [PMID: 8892780 DOI: 10.1016/s0002-8703(96)90018-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The pathophysiologic features and clinical manifestations of HCM have been elucidated by the introduction of several new diagnostic options. Knowledge of the molecular defects of HCM has advanced rapidly, and genetic screening studies have reemphasized the value of the standard electrocardiogram as an initial screening tool. Analysis of heart rate variability, late potentials, and QT dispersion were not found to be reliable prognostic markers in HCM. However, measurement of dispersion of conduction is probably a sensitive technique in identifying a high risk for sudden cardiac death. Significant developments include transthoracic and transesophageal echocardiography and their role in studying the mitral valve, early detection of left ventricular chamber dilatation, analysis of coronary flow, and intraoperative echocardiography. Finally, advances in the application of magnetic resonance imaging and positron-emission tomography are underway.
Collapse
Affiliation(s)
- J L Posma
- Department of Cardiology, Thoraxcenter, University Hospital Groningen, The Netherlands
| | | | | | | | | |
Collapse
|
10
|
Silver MM, Benson LN, Wigle ED. Cardiomegaly in a young infant. Cardiovasc Pathol 1996; 5:271-7. [PMID: 25851668 DOI: 10.1016/1054-8807(96)00025-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/13/1995] [Revised: 02/13/1996] [Accepted: 02/22/1996] [Indexed: 10/18/2022] Open
Affiliation(s)
- M M Silver
- Department of Pathology, The Hospital for Sick Children, Toronto, Canada
| | - L N Benson
- Department of Paediatrics, The Hospital for Sick Children, Toronto, Canada
| | - E D Wigle
- Department of Medicine, The Toronto Hospital, Toronto, Ontario, Canada; University of Toronto, Toronto, Ontario, Canada
| |
Collapse
|
11
|
Beckmann JS. Genetic studies and molecular structures: the dystrophin associated complex. Hum Mol Genet 1996. [DOI: 10.1093/hmg/5.7.865] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|