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Desai DA, Baby A, Ananthamohan K, Green LC, Arif M, Duncan BC, Kumar M, Singh RR, Koch SE, Natesan S, Rubinstein J, Jegga AG, Sadayappan S. Roles of cMyBP-C phosphorylation on cardiac contractile dysfunction in db/db mice. JOURNAL OF MOLECULAR AND CELLULAR CARDIOLOGY PLUS 2024; 8:100075. [PMID: 38957358 PMCID: PMC11218625 DOI: 10.1016/j.jmccpl.2024.100075] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 07/04/2024]
Abstract
Type 2 diabetes mellitus (T2DM) is a metabolic disease and comorbidity associated with several conditions, including cardiac dysfunction leading to heart failure with preserved ejection fraction (HFpEF), in turn resulting in T2DM-induced cardiomyopathy (T2DM-CM). However, the molecular mechanisms underlying the development of T2DM-CM are poorly understood. It is hypothesized that molecular alterations in myopathic genes induced by diabetes promote the development of HFpEF, whereas cardiac myosin inhibitors can rescue the resultant T2DM-mediated cardiomyopathy. To test this hypothesis, a Leptin receptor-deficient db/db homozygous (Lepr db/db) mouse model was used to define the pathogenesis of T2DM-CM. Echocardiographic studies at 4 and 6 months revealed that Lepr db/db hearts started developing cardiac dysfunction by four months, and left ventricular hypertrophy with diastolic dysfunction was evident at 6 months. RNA-seq data analysis, followed by functional enrichment, revealed the differential regulation of genes related to cardiac dysfunction in Lepr db/db heart tissues. Strikingly, the level of cardiac myosin binding protein-C phosphorylation was significantly increased in Lepr db/db mouse hearts. Finally, using isolated skinned papillary muscles and freshly isolated cardiomyocytes, CAMZYOS ® (mavacamten, MYK-461), a prescription heart medicine used for symptomatic obstructive hypertrophic cardiomyopathy treatment, was tested for its ability to rescue T2DM-CM. Compared with controls, MYK-461 significantly reduced force generation in papillary muscle fibers and cardiomyocyte contractility in the db/db group. This line of evidence shows that 1) T2DM-CM is associated with hyperphosphorylation of cardiac myosin binding protein-C and 2) MYK-461 significantly lessened disease progression in vitro, suggesting its promise as a treatment for HFpEF.
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Affiliation(s)
- Darshini A. Desai
- Center for Cardiovascular Research, Department of Internal Medicine, Division of Cardiovascular Health and Disease, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA
| | - Akhil Baby
- Center for Cardiovascular Research, Department of Internal Medicine, Division of Cardiovascular Health and Disease, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA
- Department of Genetic Engineering, School of Biotechnology, Madurai Kamaraj University, Madurai 625021, India
| | - Kalyani Ananthamohan
- Center for Cardiovascular Research, Department of Internal Medicine, Division of Cardiovascular Health and Disease, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA
| | - Lisa C. Green
- Center for Cardiovascular Research, Department of Internal Medicine, Division of Cardiovascular Health and Disease, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA
| | - Mohammed Arif
- Center for Cardiovascular Research, Department of Internal Medicine, Division of Cardiovascular Health and Disease, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA
| | - Brittany C. Duncan
- Center for Cardiovascular Research, Department of Internal Medicine, Division of Cardiovascular Health and Disease, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA
| | - Mohit Kumar
- Center for Cardiovascular Research, Department of Internal Medicine, Division of Cardiovascular Health and Disease, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA
| | - Rohit R. Singh
- Center for Cardiovascular Research, Department of Internal Medicine, Division of Cardiovascular Health and Disease, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA
| | - Sheryl E. Koch
- Center for Cardiovascular Research, Department of Internal Medicine, Division of Cardiovascular Health and Disease, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA
| | - Sankar Natesan
- Department of Genetic Engineering, School of Biotechnology, Madurai Kamaraj University, Madurai 625021, India
| | - Jack Rubinstein
- Center for Cardiovascular Research, Department of Internal Medicine, Division of Cardiovascular Health and Disease, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA
| | - Anil G. Jegga
- Division of Biomedical Informatics, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH, USA
- Department of Pediatrics, College of Medicine, University of Cincinnati, Cincinnati, OH, USA
| | - Sakthivel Sadayappan
- Center for Cardiovascular Research, Department of Internal Medicine, Division of Cardiovascular Health and Disease, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA
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2
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Rosas PC, Solaro RJ. Implications of S-glutathionylation of sarcomere proteins in cardiac disorders, therapies, and diagnosis. Front Cardiovasc Med 2023; 9:1060716. [PMID: 36762302 PMCID: PMC9902711 DOI: 10.3389/fcvm.2022.1060716] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Accepted: 12/29/2022] [Indexed: 01/25/2023] Open
Abstract
The discovery that cardiac sarcomere proteins are substrates for S-glutathionylation and that this post-translational modification correlates strongly with diastolic dysfunction led to new concepts regarding how levels of oxidative stress affect the heartbeat. Major sarcomere proteins for which there is evidence of S-glutathionylation include cardiac myosin binding protein C (cMyBP-C), actin, cardiac troponin I (cTnI) and titin. Our hypothesis is that these S-glutathionylated proteins are significant factors in acquired and familial disorders of the heart; and, when released into the serum, provide novel biomarkers. We consider the molecular mechanisms for these effects in the context of recent revelations of how these proteins control cardiac dynamics in close collaboration with Ca2+ fluxes. These revelations were made using powerful approaches and technologies that were focused on thin filaments, thick filaments, and titin filaments. Here we integrate their regulatory processes in the sarcomere as modulated mainly by neuro-humoral control of phosphorylation inasmuch evidence indicates that S-glutathionylation and protein phosphorylation, promoting increased dynamics and modifying the Frank-Starling relation, may be mutually exclusive. Earlier studies demonstrated that in addition to cTnI as a well-established biomarker for cardiac disorders, serum levels of cMyBP-C are also a biomarker for cardiac disorders. We describe recent studies approaching the question of whether serum levels of S-glutathionylated-cMyBP-C could be employed as an important clinical tool in patient stratification, early diagnosis in at risk patients before HFpEF, determination of progression, effectiveness of therapeutic approaches, and as a guide in developing future therapies.
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Affiliation(s)
- Paola C. Rosas
- Department of Pharmacy Practice, College of Pharmacy, Chicago, IL, United States
| | - R. John Solaro
- Department of Physiology and Biophysics, College of Medicine, University of Illinois at Chicago, Chicago, IL, United States
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3
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Arif M, Nabavizadeh P, Song T, Desai D, Singh R, Bazrafshan S, Kumar M, Wang Y, Gilbert RJ, Dhandapany PS, Becker RC, Kranias EG, Sadayappan S. Genetic, clinical, molecular, and pathogenic aspects of the South Asian-specific polymorphic MYBPC3 Δ25bp variant. Biophys Rev 2020; 12:1065-1084. [PMID: 32656747 PMCID: PMC7429610 DOI: 10.1007/s12551-020-00725-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Accepted: 07/03/2020] [Indexed: 02/06/2023] Open
Abstract
Hypertrophic cardiomyopathy (HCM) is a cardiac genetic disease characterized by ventricular enlargement, diastolic dysfunction, and increased risk for sudden cardiac death. Sarcomeric genetic defects are the predominant known cause of HCM. In particular, mutations in the myosin-binding protein C gene (MYBPC3) are associated with ~ 40% of all HCM cases in which a genetic basis has been established. A decade ago, our group reported a 25-base pair deletion in intron 32 of MYBPC3 (MYBPC3Δ25bp) that is uniquely prevalent in South Asians and is associated with autosomal dominant cardiomyopathy. Although our studies suggest that this deletion results in left ventricular dysfunction, cardiomyopathies, and heart failure, the precise mechanism by which this variant predisposes to heart disease remains unclear. Increasingly appreciated, however, is the contribution of secondary risk factors, additional mutations, and lifestyle choices in augmenting or modifying the HCM phenotype in MYBPC3Δ25bp carriers. Therefore, the goal of this review article is to summarize the current research dedicated to understanding the molecular pathophysiology of HCM in South Asians with the MYBPC3Δ25bp variant. An emphasis is to review the latest techniques currently applied to explore the MYBPC3Δ25bp pathogenesis and to provide a foundation for developing new diagnostic strategies and advances in therapeutics.
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Affiliation(s)
- Mohammed Arif
- Division of Cardiovascular Health and Disease, Department of Internal Medicine, Heart, Lung and Vascular Institute, University of Cincinnati, College of Medicine, 231 Albert Sabin Way, Cincinnati, OH, 45267-0575, USA.
| | - Pooneh Nabavizadeh
- Division of Cardiovascular Health and Disease, Department of Internal Medicine, Heart, Lung and Vascular Institute, University of Cincinnati, College of Medicine, 231 Albert Sabin Way, Cincinnati, OH, 45267-0575, USA
| | - Taejeong Song
- Division of Cardiovascular Health and Disease, Department of Internal Medicine, Heart, Lung and Vascular Institute, University of Cincinnati, College of Medicine, 231 Albert Sabin Way, Cincinnati, OH, 45267-0575, USA
| | - Darshini Desai
- Division of Cardiovascular Health and Disease, Department of Internal Medicine, Heart, Lung and Vascular Institute, University of Cincinnati, College of Medicine, 231 Albert Sabin Way, Cincinnati, OH, 45267-0575, USA
| | - Rohit Singh
- Division of Cardiovascular Health and Disease, Department of Internal Medicine, Heart, Lung and Vascular Institute, University of Cincinnati, College of Medicine, 231 Albert Sabin Way, Cincinnati, OH, 45267-0575, USA
| | - Sholeh Bazrafshan
- Division of Cardiovascular Health and Disease, Department of Internal Medicine, Heart, Lung and Vascular Institute, University of Cincinnati, College of Medicine, 231 Albert Sabin Way, Cincinnati, OH, 45267-0575, USA
| | - Mohit Kumar
- Division of Cardiovascular Health and Disease, Department of Internal Medicine, Heart, Lung and Vascular Institute, University of Cincinnati, College of Medicine, 231 Albert Sabin Way, Cincinnati, OH, 45267-0575, USA
| | - Yigang Wang
- Department of Pathology and Laboratory Medicine, University of Cincinnati, College of Medicine, Cincinnati, OH, 45267, USA
| | - Richard J Gilbert
- Research Service, Providence VA Medical Center, Providence, RI, 02908, USA
| | - Perundurai S Dhandapany
- Centre for Cardiovascular Biology and Disease, Institute for Stem Cell Biology and Regenerative Medicine (inStem), Bangalore, India
- The Knight Cardiovascular Institute, Oregon Health and Science University, Portland, OR, USA
- Department of Medicine, Oregon Health and Science University, Portland, OR, USA
- Department of Molecular and Medical Genetics, Oregon Health and Science University, Portland, OR, USA
| | - Richard C Becker
- Division of Cardiovascular Health and Disease, Department of Internal Medicine, Heart, Lung and Vascular Institute, University of Cincinnati, College of Medicine, 231 Albert Sabin Way, Cincinnati, OH, 45267-0575, USA
| | - Evangelia G Kranias
- Department of Pharmacology and Systems Physiology, University of Cincinnati, College of Medicine, Cincinnati, OH, 45267, USA
| | - Sakthivel Sadayappan
- Division of Cardiovascular Health and Disease, Department of Internal Medicine, Heart, Lung and Vascular Institute, University of Cincinnati, College of Medicine, 231 Albert Sabin Way, Cincinnati, OH, 45267-0575, USA
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Holmes JB, Doh CY, Mamidi R, Li J, Stelzer JE. Strategies for targeting the cardiac sarcomere: avenues for novel drug discovery. Expert Opin Drug Discov 2020; 15:457-469. [PMID: 32067508 PMCID: PMC7065952 DOI: 10.1080/17460441.2020.1722637] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Accepted: 01/24/2020] [Indexed: 01/10/2023]
Abstract
Introduction: Heart failure remains one of the largest clinical challenges in the United States. Researchers have continually searched for more effective heart failure treatments that target the cardiac sarcomere but have found few successes despite numerous expensive cardiovascular clinical trials. Among many reasons, the high failure rate of cardiovascular clinical trials may be partly due to incomplete characterization of a drug candidate's complex interaction with cardiac physiology.Areas covered: In this review, the authors address the issue of preclinical cardiovascular studies of sarcomere-targeting heart failure therapies. The authors consider inherent tradeoffs made between mechanistic transparency and physiological fidelity for several relevant preclinical techniques at the atomic, molecular, heart muscle fiber, whole heart, and whole-organism levels. Thus, the authors suggest a comprehensive, bottom-up approach to preclinical cardiovascular studies that fosters scientific rigor and hypothesis-driven drug discovery.Expert opinion: In the authors' opinion, the implementation of hypothesis-driven drug discovery practices, such as the bottom-up approach to preclinical cardiovascular studies, will be imperative for the successful development of novel heart failure treatments. However, additional changes to clinical definitions of heart failure and current drug discovery culture must accompany the bottom-up approach to maximize the effectiveness of hypothesis-driven drug discovery.
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Affiliation(s)
- Joshua B Holmes
- Department of Physiology and Biophysics, School of Medicine, Case Western Reserve University, Cleveland, OH, USA
| | - Chang Yoon Doh
- Department of Physiology and Biophysics, School of Medicine, Case Western Reserve University, Cleveland, OH, USA
| | - Ranganath Mamidi
- Department of Physiology and Biophysics, School of Medicine, Case Western Reserve University, Cleveland, OH, USA
| | - Jiayang Li
- Department of Physiology and Biophysics, School of Medicine, Case Western Reserve University, Cleveland, OH, USA
| | - Julian E Stelzer
- Department of Physiology and Biophysics, School of Medicine, Case Western Reserve University, Cleveland, OH, USA
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5
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Tsukamoto O. Direct Sarcomere Modulators Are Promising New Treatments for Cardiomyopathies. Int J Mol Sci 2019; 21:ijms21010226. [PMID: 31905684 PMCID: PMC6982115 DOI: 10.3390/ijms21010226] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Revised: 12/24/2019] [Accepted: 12/25/2019] [Indexed: 01/10/2023] Open
Abstract
Mutations in sarcomere genes can cause both hypertrophic cardiomyopathy (HCM) and dilated cardiomyopathy (DCM). However, the complex genotype-phenotype relationships in pathophysiology of cardiomyopathies by gene or mutation location are not fully understood. In addition, it is still unclear how mutations within same molecule result in different clinical phenotypes such as HCM and DCM. To clarify how the initial functional insult caused by a subtle change in one protein component of the sarcomere with a given mutation is critical for the development of proper effective treatments for cardiomyopathies. Fortunately, recent technological advances and the development of direct sarcomere modulators have provided a more detailed understanding of the molecular mechanisms that govern the effects of specific mutations. The direct inhibition of sarcomere contractility may be able to suppress the development and progression of HCM with hypercontractile mutations and improve clinical parameters in patients with HCM. On the other hand, direct activation of sarcomere contractility appears to exert unexpected beneficial effects such as reverse remodeling and lower heart rate without increasing adverse cardiovascular events in patients with systolic heart failure due to DCM. Direct sarcomere modulators that can positively influence the natural history of cardiomyopathies represent promising treatment options.
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Affiliation(s)
- Osamu Tsukamoto
- Department of Medical Biochemistry, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita 565-0871, Japan; ; Tel.: +81-6-6879-3492
- Department of Medical Biochemistry, Graduate School of Frontier Bioscience, Osaka University, 1-1 Yamadaoka, Suita 565-0871, Japan
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6
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Abstract
Irving and Craig reflect on new work showing that thick filament activation involves myosin motors returning to their OFF state during diastole.
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Affiliation(s)
- Thomas C Irving
- Center for Synchrotron Radiation Research and Instrumentation and Department of Biological Sciences, Illinois Institute of Technology, Chicago, IL
| | - Roger Craig
- Division of Cell Biology and Imaging, Department of Radiology, University of Massachusetts Medical School, Worcester, MA
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7
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Mamidi R, Li J, Doh CY, Holmes JB, Stelzer JE. Lost in translation: Interpreting cardiac muscle mechanics data in clinical practice. Arch Biochem Biophys 2019; 662:213-218. [PMID: 30576628 PMCID: PMC6345594 DOI: 10.1016/j.abb.2018.12.021] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Revised: 10/25/2018] [Accepted: 12/17/2018] [Indexed: 01/10/2023]
Abstract
Current inotropic therapies improve systolic function in heart failure patients but also elicit undesirable side effects such as arrhythmias and increased intracellular Ca2+ transients. In order to maintain myocyte Ca2+ homeostasis, the increased cytosolic Ca2+ needs to be actively transported back to sarcoplasmic reticulum leading to depleted ATP reserves. Thus, an emerging approach is to design sarcomere-based treatments to correct impaired contractility via a direct and allosteric modulation of myosin's intrinsic force-generating behavior -a concept that potentially avoids the "off-target" effects. To achieve this goal, various biophysical approaches are utilized to investigate the mechanistic impact of sarcomeric modulators but information derived from diverse approaches is not fully integrated into therapeutic applications. This is in part due to the lack of information that provides a coherent connecting link between biophysical data to in vivo function. Hence, our ability to clearly discern the drug-mediated impact on whole-heart function is diminished. Reducing this translational barrier can significantly accelerate clinical progress related to sarcomere-based therapies by optimizing drug-dosing and treatment duration protocols based on information obtained from biophysical studies. Therefore, we attempt to link biophysical mechanical measurements obtained in isolated cardiac muscle and in vivo contractile function.
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Affiliation(s)
- Ranganath Mamidi
- Department of Physiology and Biophysics, School of Medicine, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Jiayang Li
- Department of Physiology and Biophysics, School of Medicine, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Chang Yoon Doh
- Department of Physiology and Biophysics, School of Medicine, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Joshua B Holmes
- Department of Physiology and Biophysics, School of Medicine, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Julian E Stelzer
- Department of Physiology and Biophysics, School of Medicine, Case Western Reserve University, Cleveland, OH, 44106, USA.
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8
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Mamidi R, Li J, Doh CY, Verma S, Stelzer JE. Impact of the Myosin Modulator Mavacamten on Force Generation and Cross-Bridge Behavior in a Murine Model of Hypercontractility. J Am Heart Assoc 2018; 7:e009627. [PMID: 30371160 PMCID: PMC6201428 DOI: 10.1161/jaha.118.009627] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Accepted: 07/27/2018] [Indexed: 01/09/2023]
Abstract
Background Recent studies suggest that mavacamten (Myk461), a small myosin-binding molecule, decreases hypercontractility in myocardium expressing hypertrophic cardiomyopathy-causing missense mutations in myosin heavy chain. However, the predominant feature of most mutations in cardiac myosin binding protein-C ( cMyBPC ) that cause hypertrophic cardiomyopathy is reduced total cMyBPC expression, and the impact of Myk461 on cMyBPC -deficient myocardium is currently unknown. Methods and Results We measured the impact of Myk461 on steady-state and dynamic cross-bridge ( XB ) behavior in detergent-skinned mouse wild-type myocardium and myocardium lacking cMyBPC (knockout (KO)). KO myocardium exhibited hypercontractile XB behavior as indicated by significant accelerations in rates of XB detachment (krel) and recruitment (kdf) at submaximal Ca2+ activations. Incubation of KO and wild-type myocardium with Myk461 resulted in a dose-dependent force depression, and this impact was more pronounced at low Ca2+ activations. Interestingly, Myk461-induced force depressions were less pronounced in KO myocardium, especially at low Ca2+ activations, which may be because of increased acto-myosin XB formation and potential disruption of super-relaxed XB s in KO myocardium. Additionally, Myk461 slowed krel in KO myocardium but not in wild-type myocardium, indicating increased XB " on" time. Furthermore, the greater degree of Myk461-induced slowing in kdf and reduction in XB recruitment magnitude in KO myocardium normalized the XB behavior back to wild-type levels. Conclusions This is the first study to demonstrate that Myk461-induced force depressions are modulated by cMyBPC expression levels in the sarcomere, and emphasizes that clinical use of Myk461 may need to be optimized based on the molecular trigger that underlies the hypertrophic cardiomyopathy phenotype.
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Affiliation(s)
- Ranganath Mamidi
- Department of Physiology and BiophysicsSchool of MedicineCase Western Reserve UniversityClevelandOH
| | - Jiayang Li
- Department of Physiology and BiophysicsSchool of MedicineCase Western Reserve UniversityClevelandOH
| | - Chang Yoon Doh
- Department of Physiology and BiophysicsSchool of MedicineCase Western Reserve UniversityClevelandOH
| | - Sujeet Verma
- Department of Horticulture SciencesIFAS, Gulf Coast Research and Education CenterUniversity of FloridaWimauma
| | - Julian E. Stelzer
- Department of Physiology and BiophysicsSchool of MedicineCase Western Reserve UniversityClevelandOH
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9
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Mohamed IA, Krishnamoorthy NT, Nasrallah GK, Da'as SI. The Role of Cardiac Myosin Binding Protein C3 in Hypertrophic Cardiomyopathy-Progress and Novel Therapeutic Opportunities. J Cell Physiol 2017; 232:1650-1659. [PMID: 27731493 DOI: 10.1002/jcp.25639] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Accepted: 10/07/2016] [Indexed: 11/11/2022]
Abstract
Hypertrophic cardiomyopathy (HCM) is a common autosomal dominant genetic cardiovascular disorder marked by genetic and phenotypic heterogeneity. Mutations in the gene encodes the cardiac myosin-binding protein C, cMYBPC3 is amongst the various sarcomeric genes that are associated with HCM. These mutations produce mutated mRNAs and truncated cMyBP-C proteins. In this review, we will discuss the implications and molecular mechanisms involved in MYBPC3 different mutations. Further, we will highlight the novel targets that can be developed into potential therapeutics for the treatment of HMC. J. Cell. Physiol. 232: 1650-1659, 2017. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Iman A Mohamed
- Department of Biomedical Science, Zewail City of Science and Technology, Giza, Egypt
| | - Navaneethakrishnan T Krishnamoorthy
- Division of Experimental Genetics, Sidra Medical and Research Center, Doha, Qatar.,Heart Science Centre, National Heart and Lung Institute, Imperial College London, London, UK
| | - Gheyath K Nasrallah
- Department of Biomedical Science, College of Health Science, Qatar University, Doha, Qatar.,Biomedical Research Center, Qatar University, Doha, Qatar
| | - Sahar I Da'as
- Division of Experimental Genetics, Sidra Medical and Research Center, Doha, Qatar.,Department of Biomedical and Biological Sciences, Hamad Bin Khalifa University, Doha, Qatar
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10
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Starr ER, Basuroy T, Fan X, Du S. Phosphorylation of cardiac myosin binding protein-C regulates heart contraction and dilatation in vivo during β-adrenergic receptor activation. J Physiol 2016; 594:4015-6. [PMID: 27417672 DOI: 10.1113/jp272680] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Affiliation(s)
- Eric R Starr
- Biomedical Sciences Program in Neurosciences and Neurological Disorders, Department of Neurosciences, College of Medicine and Life Sciences, University of Toledo, 3000 Arlington Avenue, Toledo, OH, 43614, USA.
| | - Tupa Basuroy
- Biomedical Sciences Program in Cancer Biology, Department of Biochemistry and Cancer Biology, College of Medicine and Life Sciences, University of Toledo, 3000 Arlington Avenue, Toledo, OH, 43614, USA
| | - Xiaoming Fan
- Biomedical Sciences Program in Molecular Medicine, Department of Medicine, University of Toledo, College of Medicine and Life Sciences, 3000 Arlington Avenue, Toledo, Ohio, 43614, USA
| | - Shengnan Du
- Biomedical Sciences Program in Cancer Biology, Department of Biochemistry and Cancer Biology, College of Medicine and Life Sciences, University of Toledo, 3000 Arlington Avenue, Toledo, OH, 43614, USA
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11
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Neves JS, Leite-Moreira AM, Neiva-Sousa M, Almeida-Coelho J, Castro-Ferreira R, Leite-Moreira AF. Acute Myocardial Response to Stretch: What We (don't) Know. Front Physiol 2016; 6:408. [PMID: 26779036 PMCID: PMC4700209 DOI: 10.3389/fphys.2015.00408] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2015] [Accepted: 12/11/2015] [Indexed: 12/24/2022] Open
Abstract
Myocardial stretch, as result of acute hemodynamic overload, is one of the most frequent challenges to the heart and the ability of the heart to intrinsically adapt to it is essential to prevent circulatory congestion. In this review, we highlight the historical background, the currently known mechanisms, as well as the gaps in the understanding of this physiological response. The systolic adaptation to stretch is well-known for over 100 years, being dependent on an immediate increase in contractility—known as the Frank-Starling mechanism—and a further progressive increase—the slow force response. On the other hand, its diastolic counterpart remains largely unstudied. Mechanosensors are structures capable of perceiving mechanical signals and activating pathways that allow their transduction into biochemical responses. Although the connection between these structures and stretch activated pathways remains elusive, we emphasize those most likely responsible for the initiation of the acute response. Calcium-dependent pathways, including angiotensin- and endothelin-related pathways; and cGMP-dependent pathways, comprising the effects of nitric oxide and cardiac natriuretic hormones, embody downstream signaling. The ischemic setting, a paradigmatic situation of acute hemodynamic overload, is also touched upon. Despite the relevant knowledge accumulated, there is much that we still do not know. The quest for further understanding the myocardial response to acute stretch may provide new insights, not only in its physiological importance, but also in the prevention and treatment of cardiovascular diseases.
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Affiliation(s)
- João S Neves
- Department of Physiology and Cardiothoracic Surgery, Faculty of Medicine of the University of Porto Porto, Portugal
| | - André M Leite-Moreira
- Department of Physiology and Cardiothoracic Surgery, Faculty of Medicine of the University of Porto Porto, Portugal
| | - Manuel Neiva-Sousa
- Department of Physiology and Cardiothoracic Surgery, Faculty of Medicine of the University of Porto Porto, Portugal
| | - João Almeida-Coelho
- Department of Physiology and Cardiothoracic Surgery, Faculty of Medicine of the University of Porto Porto, Portugal
| | - Ricardo Castro-Ferreira
- Department of Physiology and Cardiothoracic Surgery, Faculty of Medicine of the University of Porto Porto, Portugal
| | - Adelino F Leite-Moreira
- Department of Physiology and Cardiothoracic Surgery, Faculty of Medicine of the University of Porto Porto, Portugal
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12
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Mamidi R, Gresham KS, Li A, dos Remedios CG, Stelzer JE. Molecular effects of the myosin activator omecamtiv mecarbil on contractile properties of skinned myocardium lacking cardiac myosin binding protein-C. J Mol Cell Cardiol 2015; 85:262-72. [PMID: 26100051 DOI: 10.1016/j.yjmcc.2015.06.011] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Revised: 05/28/2015] [Accepted: 06/15/2015] [Indexed: 01/03/2023]
Abstract
Decreased expression of cardiac myosin binding protein-C (cMyBP-C) in the myocardium is thought to be a contributing factor to hypertrophic cardiomyopathy in humans, and the initial molecular defect is likely abnormal cross-bridge (XB) function which leads to impaired force generation, decreased contractile performance, and hypertrophy in vivo. The myosin activator omecamtiv mecarbil (OM) is a pharmacological drug that specifically targets the myosin XB and recent evidence suggests that OM induces a significant decrease in the in vivo motility velocity and an increase in the XB duty cycle. Thus, the molecular effects of OM maybe beneficial in improving contractile function in skinned myocardium lacking cMyBP-C because absence of cMyBP-C in the sarcomere accelerates XB kinetics and enhances XB turnover rate, which presumably reduces contractile efficiency. Therefore, parameters of XB function were measured in skinned myocardium lacking cMyBP-C prior to and following OM incubation. We measured ktr, the rate of force redevelopment as an index of XB transition from both the weakly- to strongly-bound state and from the strongly- to weakly-bound states and performed stretch activation experiments to measure the rates of XB detachment (krel) and XB recruitment (kdf) in detergent-skinned ventricular preparations isolated from hearts of wild-type (WT) and cMyBP-C knockout (KO) mice. Samples from donor human hearts were also used to assess the effects of OM in cardiac muscle expressing a slow β-myosin heavy chain (β-MHC). Incubation of skinned myocardium with OM produced large enhancements in steady-state force generation which were most pronounced at low levels of [Ca(2+)] activations, suggesting that OM cooperatively recruits additional XB's into force generating states. Despite a large increase in steady-state force generation following OM incubation, parallel accelerations in XB kinetics as measured by ktr were not observed, and there was a significant OM-induced decrease in krel which was more pronounced in the KO skinned myocardium compared to WT skinned myocardium (58% in WT vs. 76% in KO at pCa 6.1), such that baseline differences in krel between KO and WT skinned myocardium were no longer apparent following OM-incubation. A significant decrease in the kdf was also observed following OM incubation in all groups, which may be related to the increase in the number of cooperatively recruited XB's at low Ca(2+)-activations which slows the overall rate of force generation. Our results indicate that OM may be a useful pharmacological approach to normalize hypercontractile XB kinetics in myocardium with decreased cMyBP-C expression due to its molecular effects on XB behavior.
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Affiliation(s)
- Ranganath Mamidi
- Department of Physiology and Biophysics, School of Medicine, Case Western Reserve University, Cleveland, OH 44106 USA
| | - Kenneth S Gresham
- Department of Physiology and Biophysics, School of Medicine, Case Western Reserve University, Cleveland, OH 44106 USA
| | - Amy Li
- Muscle Research Unit, Bosch Institute, University of Sydney, Sydney Australia
| | | | - Julian E Stelzer
- Department of Physiology and Biophysics, School of Medicine, Case Western Reserve University, Cleveland, OH 44106 USA.
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13
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Abstract
Various human diseases can disrupt the balance between muscle contraction and relaxation. Sarcomeric modulators can be used to readjust this balance either indirectly by intervening in signalling pathways or directly through interaction with the muscle proteins that control contraction. Such agents represent a novel approach to treating any condition in which striated muscle function is compromised, including heart failure, cardiomyopathies, skeletal myopathies and a wide range of neuromuscular conditions. Here, we review agents that modulate the mechanical function of the sarcomere, focusing on emerging compounds that target myosin or the troponin complex.
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14
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Tardiff JC, Carrier L, Bers DM, Poggesi C, Ferrantini C, Coppini R, Maier LS, Ashrafian H, Huke S, van der Velden J. Targets for therapy in sarcomeric cardiomyopathies. Cardiovasc Res 2015; 105:457-70. [PMID: 25634554 DOI: 10.1093/cvr/cvv023] [Citation(s) in RCA: 106] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
To date, no compounds or interventions exist that treat or prevent sarcomeric cardiomyopathies. Established therapies currently improve the outcome, but novel therapies may be able to more fundamentally affect the disease process and course. Investigations of the pathomechanisms are generating molecular insights that can be useful for the design of novel specific drugs suitable for clinical use. As perturbations in the heart are stage-specific, proper timing of drug treatment is essential to prevent initiation and progression of cardiac disease in mutation carrier individuals. In this review, we emphasize potential novel therapies which may prevent, delay, or even reverse hypertrophic cardiomyopathy caused by sarcomeric gene mutations. These include corrections of genetic defects, altered sarcomere function, perturbations in intracellular ion homeostasis, and impaired myocardial energetics.
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Affiliation(s)
- Jil C Tardiff
- Department of Medicine and Cellular and Molecular Medicine, University of Arizona, 1656 East Mabel Street, MRB 312, Tucson, AZ 85724-5217, USA
| | - Lucie Carrier
- Department of Experimental Pharmacology and Toxicology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany DZHK (German Centre for Cardiovascular Research), partner site Hamburg/Kiel/Lübeck, Hamburg, Germany
| | - Donald M Bers
- Department of Pharmacology, University of California, Davis, CA, USA
| | - Corrado Poggesi
- Center of Molecular Medicine and Applied Biophysics (CIMMBA), University of Florence, Florence, Italy
| | - Cecilia Ferrantini
- Center of Molecular Medicine and Applied Biophysics (CIMMBA), University of Florence, Florence, Italy
| | - Raffaele Coppini
- Center of Molecular Medicine and Applied Biophysics (CIMMBA), University of Florence, Florence, Italy
| | - Lars S Maier
- Klinik und Poliklinik für Innere Medizin II, Universitätsklinikum, Regensburg, Germany
| | - Houman Ashrafian
- Experimental Therapeutics and Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Sabine Huke
- Division of Clinical Pharmacology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Jolanda van der Velden
- Department of Physiology, Institute for Cardiovascular Research (ICaR-VU), VU University Medical Center, van der Boechorststraat 7, 1081 BT Amsterdam, The Netherlands ICIN-Netherlands Heart Institute, Utrecht, the Netherlands
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15
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Mybpc3 gene therapy for neonatal cardiomyopathy enables long-term disease prevention in mice. Nat Commun 2014; 5:5515. [PMID: 25463264 DOI: 10.1038/ncomms6515] [Citation(s) in RCA: 117] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2014] [Accepted: 10/08/2014] [Indexed: 01/24/2023] Open
Abstract
Homozygous or compound heterozygous frameshift mutations in MYBPC3 encoding cardiac myosin-binding protein C (cMyBP-C) cause neonatal hypertrophic cardiomyopathy (HCM), which rapidly evolves into systolic heart failure and death within the first year of life. Here we show successful long-term Mybpc3 gene therapy in homozygous Mybpc3-targeted knock-in (KI) mice, which genetically mimic these human neonatal cardiomyopathies. A single systemic administration of adeno-associated virus (AAV9)-Mybpc3 in 1-day-old KI mice prevents the development of cardiac hypertrophy and dysfunction for the observation period of 34 weeks and increases Mybpc3 messenger RNA (mRNA) and cMyBP-C protein levels in a dose-dependent manner. Importantly, Mybpc3 gene therapy unexpectedly also suppresses accumulation of mutant mRNAs. This study reports the first successful long-term gene therapy of HCM with correction of both haploinsufficiency and production of poison peptides. In the absence of alternative treatment options except heart transplantation, gene therapy could become a realistic treatment option for severe neonatal HCM.
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