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Wang H, Lin Y, Zhang R, Chen Y, Ji W, Li S, Wang L, Tan R, Yuan J. Programmed Exercise Attenuates Familial Hypertrophic Cardiomyopathy in Transgenic E22K Mice via Inhibition of PKC-α/NFAT Pathway. Front Cardiovasc Med 2022; 9:808163. [PMID: 35265680 PMCID: PMC8899095 DOI: 10.3389/fcvm.2022.808163] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Accepted: 01/24/2022] [Indexed: 12/12/2022] Open
Abstract
Familial hypertrophic cardiomyopathy (FHCM), an autosomal dominant disease, is caused by mutations in genes encoding cardiac sarcomeric proteins. E22K, a mutation in the myosin regulatory light chain sarcomere gene, is associated with the development of FHCM. However, the molecular mechanisms by which E22K mutation promotes septal hypertrophy are still elusive. The hypertrophic markers, including beta-myosin heavy chain, atrial natriuretic peptide and B-type natriuretic peptide, were upregulated, as detected by fluorescence quantitative PCR. The gene expression profiles were greatly altered in the left ventricle of E22K mutant mice. Among these genes, nuclear factor of activated T cells (NFAT) and protein kinase C-alpha (PKC-α) were upregulated, and their protein expression levels were also verified to be elevated. The fibrosis markers, such as phosphorylated Smad and transforming growth factor beta receptor, were also elevated in transgenic E22K mice. After receiving 6 weeks of procedural exercise training, the expression levels of PKC-α and NFAT were reversed in E22K mouse hearts. In addition, the expression levels of several fibrosis-related genes such as transforming growth factor beta receptor 1, Smad4, and alpha smooth muscle actin in E22K mouse hearts were also reversed. Genes that associated with cardiac remodeling such as myocyte enhancer factor 2C, extracellular matrix protein 2 and fibroblast growth factor 12 were reduced after exercising. Taken together, our results indicate that exercise can improve hypertrophy and fibrosis-related indices in transgenic E22K mice via PKC-α/NFAT pathway, which provide new insight into the prevention and treatment of familial hypertrophic cardiomyopathy.
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Affiliation(s)
- Haiying Wang
- Department of Physiology, Institute of Basic Medical College, Jining Medical University, Jining, China
| | - Yuedong Lin
- Cardiac Emergency Department, Affiliated Hospital of Jining Medical University, Jining, China
| | - Ran Zhang
- Institute of Basic Medical College, Jining Medical University, Jining, China
| | - Yafen Chen
- Institute of Basic Medical College, Jining Medical University, Jining, China
| | - Wei Ji
- Institute of Basic Medical College, Jining Medical University, Jining, China
| | - Shenwei Li
- Institute of Basic Medical College, Jining Medical University, Jining, China
| | - Li Wang
- School of Nursing, Medical College, Soochow University, Suzhou, China
- *Correspondence: Li Wang
| | - Rubin Tan
- Department of Physiology, Basic Medical School, Xuzhou Medical University, Xuzhou, China
- Rubin Tan
| | - Jinxiang Yuan
- The Collaborative Innovation Center, Jining Medical University, Jining, China
- Jinxiang Yuan
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2
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Chen YJ, Chien CS, Chiang CE, Chen CH, Cheng HM. From Genetic Mutations to Molecular Basis of Heart Failure Treatment: An Overview of the Mechanism and Implication of the Novel Modulators for Cardiac Myosin. Int J Mol Sci 2021; 22:6617. [PMID: 34205587 PMCID: PMC8234187 DOI: 10.3390/ijms22126617] [Citation(s) in RCA: 4] [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: 05/29/2021] [Revised: 06/11/2021] [Accepted: 06/17/2021] [Indexed: 02/06/2023] Open
Abstract
Heart failure (HF) is a syndrome encompassing several important etiologies that lead to the imbalance between oxygen demand and supply. Despite the usage of guideline-directed medical therapy for HF has shown better outcomes, novel therapeutic strategies are desirable, especially for patients with preserved or mildly reduced left ventricular ejection fraction. In this regard, understanding the molecular basis for cardiomyopathies is expected to fill in the knowledge gap and generate new therapies to improve prognosis for HF. This review discusses an evolutionary mechanism designed to regulate cardiac contraction and relaxation through the most often genetically determined cardiomyopathies associated with HF. In addition, both the myosin inhibitor and myosin activator are promising new treatments for cardiomyopathies. A comprehensive review from genetic mutations to the molecular basis of direct sarcomere modulators will help shed light on future studies for a better characterization of HF etiologies and potential therapeutic targets.
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Affiliation(s)
- Yu-Jen Chen
- Department of Internal Medicine, Division of Cardiovascular Medicine, Wan Fang Hospital, Taipei Medical University, Taipei 116081, Taiwan;
- Department of Internal Medicine, Division of Cardiology, School of Medicine, College of Medicine, Taipei Medical University, Taipei 110301, Taiwan
- Institute of Public Health, National Yang Ming Chiao Tung University, Taipei 112304, Taiwan
| | - Chian-Shiu Chien
- Innovative Cellular Therapy Center, Department of Medical Research, Taipei Veterans General Hospital, Taipei 112201, Taiwan;
| | - Chern-En Chiang
- General Clinical Research Center, Taipei Veterans General Hospital, Taipei 112201, Taiwan;
- Department of Medicine, National Yang Ming Chiao Tung University College of Medicine, Taipei 112304, Taiwan
| | - Chen-Huan Chen
- Department of Medical Education, Taipei Veterans General Hospital, Taipei 112201, Taiwan;
- College of Medicine, National Yang Ming Chiao Tung University, Taipei 112201, Taiwan
| | - Hao-Min Cheng
- Institute of Public Health, National Yang Ming Chiao Tung University, Taipei 112304, Taiwan
- Department of Medicine, National Yang Ming Chiao Tung University College of Medicine, Taipei 112304, Taiwan
- Center for Evidence-Based Medicine, Taipei Veterans General Hospital, Taipei 112201, Taiwan
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3
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Savich Y, Binder BP, Thompson AR, Thomas DD. Myosin lever arm orientation in muscle determined with high angular resolution using bifunctional spin labels. J Gen Physiol 2019; 151:1007-1016. [PMID: 31227551 PMCID: PMC6683674 DOI: 10.1085/jgp.201812210] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2018] [Revised: 02/15/2019] [Accepted: 05/29/2019] [Indexed: 02/03/2023] Open
Abstract
High-resolution structural information is invaluable for understanding muscle function. Savich et al. use bifunctional spin labeling to determine the orientation of the myosin lever arm in muscle fibers at high resolution under ambient conditions, augmenting previous insights obtained from fluorescence and EM. Despite advances in x-ray crystallography, cryo-electron microscopy (cryo-EM), and fluorescence polarization, none of these techniques provide high-resolution structural information about the myosin light chain domain (LCD; lever arm) under ambient conditions in vertebrate muscle. Here, we measure the orientation of LCD elements in demembranated muscle fibers by electron paramagnetic resonance (EPR) using a bifunctional spin label (BSL) with an angular resolution of 4°. To achieve stereoselective site-directed labeling with BSL, we engineered a pair of cysteines in the myosin regulatory light chain (RLC), either on helix E or helix B, which are roughly parallel or perpendicular to the myosin lever arm, respectively. By exchanging BSL-labeled RLC onto oriented muscle fibers, we obtain EPR spectra from which the angular distributions of BSL, and thus the lever arm, can be determined with high resolution relative to the muscle fiber axis. In the absence of ATP (rigor), each of the two labeled helices exhibits both ordered (σ ∼9–11°) and disordered (σ > 38°) populations. Using these angles to determine the orientation of the lever arm (LCD combined with converter subdomain), we observe that the oriented population corresponds to a lever arm that is perpendicular to the muscle fiber axis and that the addition of ATP in the absence of Ca2+ (inducing relaxation) shifts the orientation to a much more disordered orientational distribution. Although the detected orientation of the myosin light chain lever arm is ∼33° different than predicted from a standard “lever arm down” model based on cryo-EM of actin decorated with isolated myosin heads, it is compatible with, and thus augments and clarifies, fluorescence polarization, x-ray interference, and EM data obtained from muscle fibers. These results establish feasibility for high-resolution detection of myosin LCD rotation during muscle contraction.
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Affiliation(s)
- Yahor Savich
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN.,School of Physics and Astronomy, University of Minnesota, Minneapolis, MN
| | - Benjamin P Binder
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN.,Department of Chemistry, Augsburg University, Minneapolis, MN
| | - Andrew R Thompson
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN
| | - David D Thomas
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN
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Yadav S, Sitbon YH, Kazmierczak K, Szczesna-Cordary D. Hereditary heart disease: pathophysiology, clinical presentation, and animal models of HCM, RCM, and DCM associated with mutations in cardiac myosin light chains. Pflugers Arch 2019; 471:683-699. [PMID: 30706179 DOI: 10.1007/s00424-019-02257-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2018] [Revised: 12/26/2018] [Accepted: 01/13/2019] [Indexed: 02/07/2023]
Abstract
Genetic cardiomyopathies, a group of cardiovascular disorders based on ventricular morphology and function, are among the leading causes of morbidity and mortality worldwide. Such genetically driven forms of hypertrophic (HCM), dilated (DCM), and restrictive (RCM) cardiomyopathies are chronic, debilitating diseases that result from biomechanical defects in cardiac muscle contraction and frequently progress to heart failure (HF). Locus and allelic heterogeneity, as well as clinical variability combined with genetic and phenotypic overlap between different cardiomyopathies, have challenged proper clinical prognosis and provided an incentive for identification of pathogenic variants. This review attempts to provide an overview of inherited cardiomyopathies with a focus on their genetic etiology in myosin regulatory (RLC) and essential (ELC) light chains, which are EF-hand protein family members with important structural and regulatory roles. From the clinical discovery of cardiomyopathy-linked light chain mutations in patients to an array of exploratory studies in animals, and reconstituted and recombinant systems, we have summarized the current state of knowledge on light chain mutations and how they induce physiological disease states via biochemical and biomechanical alterations at the molecular, tissue, and organ levels. Cardiac myosin RLC phosphorylation and the N-terminus ELC have been discussed as two important emerging modalities with important implications in the regulation of myosin motor function, and thus cardiac performance. A comprehensive understanding of such triggers is absolutely necessary for the development of target-specific rescue strategies to ameliorate or reverse the effects of myosin light chain-related inherited cardiomyopathies.
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MESH Headings
- Animals
- Cardiomyopathy, Dilated/etiology
- Cardiomyopathy, Dilated/genetics
- Cardiomyopathy, Dilated/pathology
- Cardiomyopathy, Hypertrophic/etiology
- Cardiomyopathy, Hypertrophic/genetics
- Cardiomyopathy, Hypertrophic/pathology
- Cardiomyopathy, Restrictive/etiology
- Cardiomyopathy, Restrictive/genetics
- Cardiomyopathy, Restrictive/pathology
- Disease Models, Animal
- Humans
- Mutation
- Myosin Light Chains/genetics
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Affiliation(s)
- Sunil Yadav
- Department of Molecular and Cellular Pharmacology, University of Miami Miller School of Medicine, 1600 NW 10th Ave., Miami, FL, 33136, USA
| | - Yoel H Sitbon
- Department of Molecular and Cellular Pharmacology, University of Miami Miller School of Medicine, 1600 NW 10th Ave., Miami, FL, 33136, USA
| | - Katarzyna Kazmierczak
- Department of Molecular and Cellular Pharmacology, University of Miami Miller School of Medicine, 1600 NW 10th Ave., Miami, FL, 33136, USA
| | - Danuta Szczesna-Cordary
- Department of Molecular and Cellular Pharmacology, University of Miami Miller School of Medicine, 1600 NW 10th Ave., Miami, FL, 33136, USA.
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Claes GRF, van Tienen FHJ, Lindsey P, Krapels IPC, Helderman-van den Enden ATJM, Hoos MB, Barrois YEG, Janssen JWH, Paulussen ADC, Sels JWEM, Kuijpers SHH, van Tintelen JP, van den Berg MP, Heesen WF, Garcia-Pavia P, Perrot A, Christiaans I, Salemink S, Marcelis CLM, Smeets HJM, Brunner HG, Volders PGA, van den Wijngaard A. Hypertrophic remodelling in cardiac regulatory myosin light chain (MYL2) founder mutation carriers. Eur Heart J 2015; 37:1815-22. [PMID: 26497160 DOI: 10.1093/eurheartj/ehv522] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/01/2015] [Accepted: 09/16/2015] [Indexed: 01/25/2023] Open
Abstract
AIMS Phenotypic heterogeneity and incomplete penetrance are common in patients with hypertrophic cardiomyopathy (HCM). We aim to improve the understanding in genotype-phenotype correlations in HCM, particularly the contribution of an MYL2 founder mutation and risk factors to left ventricular hypertrophic remodelling. METHODS AND RESULTS We analysed 14 HCM families of whom 38 family members share the MYL2 c.64G > A [p.(Glu22Lys)] mutation and a common founder haplotype. In this unique cohort, we investigated factors influencing phenotypic outcome in addition to the primary mutation. The mutation alone showed benign disease manifestation with low penetrance. The co-presence of additional risk factors for hypertrophy such as hypertension, obesity, or other sarcomeric gene mutation increased disease penetrance substantially and caused HCM in 89% of MYL2 mutation carriers (P = 0.0005). The most prominent risk factor was hypertension, observed in 71% of mutation carriers with HCM and an additional risk factor. CONCLUSION The MYL2 mutation c.64G > A on its own is incapable of triggering clinical HCM in most carriers. However, the presence of an additional risk factor for hypertrophy, particularly hypertension, adds to the development of HCM. Early diagnosis of risk factors is important for early treatment of MYL2 mutation carriers and close monitoring should be guaranteed in this case. Our findings also suggest that the presence of hypertension or another risk factor for hypertrophy should not be an exclusion criterion for genetic studies.
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Affiliation(s)
- Godelieve R F Claes
- Department of Clinical Genetics, Unit Clinical Genomics, Maastricht University Medical Centre, P.O. Box 5800, 6229 GR Maastricht, The Netherlands School for Cardiovascular Diseases, Maastricht University Medical Centre, Maastricht, The Netherlands
| | - Florence H J van Tienen
- Department of Clinical Genetics, Unit Clinical Genomics, Maastricht University Medical Centre, P.O. Box 5800, 6229 GR Maastricht, The Netherlands School for Cardiovascular Diseases, Maastricht University Medical Centre, Maastricht, The Netherlands
| | - Patrick Lindsey
- Department of Clinical Genetics, Unit Clinical Genomics, Maastricht University Medical Centre, P.O. Box 5800, 6229 GR Maastricht, The Netherlands School for Cardiovascular Diseases, Maastricht University Medical Centre, Maastricht, The Netherlands
| | - Ingrid P C Krapels
- Department of Clinical Genetics, Unit Clinical Genomics, Maastricht University Medical Centre, P.O. Box 5800, 6229 GR Maastricht, The Netherlands School for Cardiovascular Diseases, Maastricht University Medical Centre, Maastricht, The Netherlands
| | - Apollonia T J M Helderman-van den Enden
- Department of Clinical Genetics, Unit Clinical Genomics, Maastricht University Medical Centre, P.O. Box 5800, 6229 GR Maastricht, The Netherlands School for Cardiovascular Diseases, Maastricht University Medical Centre, Maastricht, The Netherlands
| | - Marije B Hoos
- Department of Clinical Genetics, Unit Clinical Genomics, Maastricht University Medical Centre, P.O. Box 5800, 6229 GR Maastricht, The Netherlands School for Cardiovascular Diseases, Maastricht University Medical Centre, Maastricht, The Netherlands
| | - Yvette E G Barrois
- Department of Clinical Genetics, Unit Clinical Genomics, Maastricht University Medical Centre, P.O. Box 5800, 6229 GR Maastricht, The Netherlands School for Cardiovascular Diseases, Maastricht University Medical Centre, Maastricht, The Netherlands
| | - Johanna W H Janssen
- Department of Clinical Genetics, Unit Clinical Genomics, Maastricht University Medical Centre, P.O. Box 5800, 6229 GR Maastricht, The Netherlands
| | - Aimée D C Paulussen
- Department of Clinical Genetics, Unit Clinical Genomics, Maastricht University Medical Centre, P.O. Box 5800, 6229 GR Maastricht, The Netherlands School for Cardiovascular Diseases, Maastricht University Medical Centre, Maastricht, The Netherlands
| | - Jan-Willem E M Sels
- Department of Cardiology, Cardiovascular Research Institute Maastricht, Maastricht University Medical Centre, Maastricht, The Netherlands Department of Intensive Care, Maastricht University Medical Centre, Maastricht, The Netherlands
| | | | - J Peter van Tintelen
- Department of Clinical Genetics, Academic Medical Centre, Amsterdam, The Netherlands
| | - Maarten P van den Berg
- Department of Cardiology, University of Groningen, University Medical Centre Groningen, Groningen, The Netherlands
| | - Wilfred F Heesen
- Department of Cardiology, VieCuri Medical Centre, Venlo, The Netherlands
| | - Pablo Garcia-Pavia
- Heart Failure and Inherited Cardiac Diseases Unit, Department of Cardiology, Hospital Universitario Puerta de Hierro Majadahonda, Madrid, Spain
| | - Andreas Perrot
- Charité-Universitätsmedizin Berlin, Experimental & Clinical Research Centre, A Joint Cooperation Between the Charité Medical Faculty and the Max-Delbrück Centre for Molecular Medicine, Berlin, Germany
| | - Imke Christiaans
- Department of Clinical Genetics, Academic Medical Centre, Amsterdam, The Netherlands
| | - Simone Salemink
- Department of Human Genetics, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - Carlo L M Marcelis
- Department of Human Genetics, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - Hubert J M Smeets
- Department of Clinical Genetics, Unit Clinical Genomics, Maastricht University Medical Centre, P.O. Box 5800, 6229 GR Maastricht, The Netherlands
| | - Han G Brunner
- Department of Clinical Genetics, Unit Clinical Genomics, Maastricht University Medical Centre, P.O. Box 5800, 6229 GR Maastricht, The Netherlands Department of Human Genetics, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - Paul G A Volders
- Department of Cardiology, Cardiovascular Research Institute Maastricht, Maastricht University Medical Centre, Maastricht, The Netherlands
| | - Arthur van den Wijngaard
- Department of Clinical Genetics, Unit Clinical Genomics, Maastricht University Medical Centre, P.O. Box 5800, 6229 GR Maastricht, The Netherlands School for Cardiovascular Diseases, Maastricht University Medical Centre, Maastricht, The Netherlands
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Kimura A. Molecular genetics and pathogenesis of cardiomyopathy. J Hum Genet 2015; 61:41-50. [PMID: 26178429 DOI: 10.1038/jhg.2015.83] [Citation(s) in RCA: 76] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2015] [Accepted: 06/15/2015] [Indexed: 12/19/2022]
Abstract
Cardiomyopathy is defined as a disease of functional impairment in the cardiac muscle and its etiology includes both extrinsic and intrinsic factors. Cardiomyopathy caused by the intrinsic factors is called as primary cardiomyopathy of which two major clinical phenotypes are hypertrophic cardiomyopathy (HCM) and dilated cardiomyopathy (DCM). Genetic approaches have revealed the disease genes for hereditary primary cardiomyopathy and functional studies have demonstrated that characteristic functional alterations induced by the disease-associated mutations are closely related to the clinical types, such that increased and decreased Ca(2+) sensitivities of muscle contraction are associated with HCM and DCM, respectively. In addition, recent studies have suggested that mutations in the Z-disc components found in HCM and DCM may result in increased and decreased stiffness of sarcomere, respectively. Moreover, functional analysis of mutations in the other components of cardiac muscle have suggested that the altered response to metabolic stresses is associated with cardiomyopathy, further indicating the heterogeneity in the etiology and pathogenesis of cardiomyopathy.
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Affiliation(s)
- Akinori Kimura
- Department of Molecular Pathogenesis, Medical Research Institute, Tokyo Medical and Dental University (TMDU), Tokyo, Japan
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Li W, Rong R, Zhao S, Zhu X, Zhang K, Xiong X, Yu X, Cui Q, Li S, Chen L, Cai J, Du J. Proteomic analysis of metabolic, cytoskeletal and stress response proteins in human heart failure. J Cell Mol Med 2012; 16:59-71. [PMID: 21545686 PMCID: PMC3823093 DOI: 10.1111/j.1582-4934.2011.01336.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Human heart failure is a complex syndrome and a primary cause of morbidity and mortality in the world. However, the molecular pathways involved in the remodelling process are poorly understood. In this study, we performed exhaustive global proteomic surveys of cardiac ventricle isolated from failing and non-failing human hearts, and determined the regulatory pathway to uncover the mechanism underlying heart failure. Two-dimensional gel electrophoresis (2-DE) coupled with tandem mass spectrometry was used to identify differentially expressed proteins in specimens from failing (n = 9) and non-failing (n = 6) human hearts. A total of 25 proteins with at least 1.5-fold change in the failing heart were identified; 15 proteins were up-regulated and 10 proteins were down-regulated. The altered proteins belong to three broad functional categories: (i) metabolic [e.g. NADH dehydrogenase (ubiquinone), dihydrolipoamide dehydrogenase, and the cytochrome c oxidase subunit]; (ii) cytoskeletal (e.g. myosin light chain proteins, troponin I type 3 and transthyretin) and (iii) stress response (e.g. αB-crystallin, HSP27 and HSP20). The marked differences in the expression of selected proteins, including HSP27 and HSP20, were further confirmed by Western blot. Thus, we carried out full-scale screening of the protein changes in human heart failure and profiled proteins that may be critical in cardiac dysfunction for future mapping.
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Affiliation(s)
- Weiming Li
- Department of Cardiology, Chaoyang Hospital, The Key Laboratory of Remodelling-related Cardiovascular Diseases, Capital Medical University, Ministry of Education, Beijing, China
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8
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Three distinct actin-attached structural states of myosin in muscle fibers. Biophys J 2012; 102:1088-96. [PMID: 22404931 DOI: 10.1016/j.bpj.2011.11.4027] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2011] [Revised: 11/09/2011] [Accepted: 11/14/2011] [Indexed: 11/21/2022] Open
Abstract
We have used thiol cross-linking and electron paramagnetic resonance (EPR) to resolve structural transitions of myosin's light chain domain (LCD) and catalytic domain (CD) that are associated with force generation. Spin labels were incorporated into the LCD of muscle fibers by exchanging spin-labeled regulatory light chain for endogenous regulatory light chain, with full retention of function. To trap myosin in a structural state analogous to the elusive posthydrolysis ternary complex A.M'.D.P, we used pPDM to cross-link SH1 (Cys(707)) to SH2 (Cys(697)) on the CD. LCD orientation and dynamics were measured in three biochemical states: relaxation (A.M.T), SH1-SH2 cross-linked (A.M'.D.P analog), and rigor (A.M.D). EPR showed that the LCD of cross-linked fibers has an orientational distribution intermediate between relaxation and rigor, and saturation transfer EPR revealed slow rotational dynamics indistinguishable from that of rigor. Similar results were obtained for the CD using a bifunctional spin label to cross-link SH1-SH2, but the CD was more disordered than the LCD. We conclude that SH1-SH2 cross-linking traps a state in which both the CD and LCD are intermediate between relaxation (highly disordered and microsecond dynamics) and rigor (highly ordered and rigid), supporting the hypothesis that the cross-linked state is an A.M'D.P analog on the force generation pathway.
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9
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Kimura A. Molecular basis of hereditary cardiomyopathy: abnormalities in calcium sensitivity, stretch response, stress response and beyond. J Hum Genet 2010; 55:81-90. [PMID: 20075948 DOI: 10.1038/jhg.2009.138] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Cardiomyopathy is caused by functional abnormality of cardiac muscle. The functional abnormality involved in its etiology includes both extrinsic and intrinsic factors, and cardiomyopathy caused by the intrinsic factors is called as idiopathic or primary cardiomyopathy. There are several clinical types of primary cardiomyopathy including hypertrophic cardiomyopathy (HCM) and dilated cardiomyopathy (DCM). Linkage studies and candidate gene approaches have explored the disease genes for hereditary primary cardiomyopathy. The most notable finding was that mutations in the same disease gene can be found in different clinical types of cardiomyopathy. Functional analyses of disease-related mutations have revealed that characteristic functional alterations are associated with the clinical types, such that increased and decreased Ca(2+) sensitivity due to sarcomere mutations are associated with HCM and DCM, respectively. In addition, our recent studies have suggested that mutations in the Z-disc components found in HCM and DCM may result in increased and decreased stiffness of sarcomere; that is, stiff sarcomere and loose sarcomere, respectively, and hence altered stretch response. More recently, mutations in the components of I region were found in hereditary cardiomyopathy and the functional analyses of the mutations suggested that the altered stress response was associated with cardiomyopathy, further complicating the etiology and pathogenesis. However, elucidation of genetic etiology and functional alterations caused by the mutations shed lights on the new therapeutic approaches to hereditary cardiomyopathy, such that treatment of DCM with a Ca(2+) sensitizer prevented the disease in a mouse model.
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Affiliation(s)
- Akinori Kimura
- Department of Molecular Pathogenesis, Medical Research Institute, Tokyo Medical and Dental University, Japan.
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10
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Abstract
Cardiomyopathy is defined as a cardiac disease caused by functional abnormality of cardiac muscle, and the etiology of the functional abnormality includes both extrinsic and intrinsic factors. Cardiomyopathy caused by the intrinsic factors is defined as idiopathic or primary cardiomyopathy, and there are several clinical phenotypes, including hypertrophic cardiomyopathy (HCM) and dilated cardiomyopathy (DCM). The major intrinsic factor is gene mutations, and linkage studies, as well as candidate gene approaches, have deciphered multiple disease genes for hereditary primary cardiomyopathy. Of note is that mutations in the same disease gene can be found in different clinical phenotypes of cardiomyopathy. Functional analyses of disease-related mutations have revealed that characteristic functional alterations are associated with the clinical phenotypes, such that increased and decreased Ca(2+) sensitivity because of sarcomere mutations are associated with HCM and DCM, respectively. In addition, recent data have suggested that mutations in the Z-disc components found in HCM and DCM may result in increased and decreased stiffness of the sarcomere (ie, stiff sarcomere and loose sarcomere, respectively). More recently, mutations in the components of the I region can be found in hereditary cardiomyopathy, further complicating the etiology of primary cardiomyopathy.
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Affiliation(s)
- Akinori Kimura
- Department of Molecular Pathogenesis, Medical Research Institute, Tokyo Medical and Dental University, Tokyo, Japan.
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11
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Genetic Polymorphisms of MYL2 and ADCYAP1R1 Genes and Their Association with Carcass Traits in Finished Pigs. JOURNAL OF ANIMAL SCIENCE AND TECHNOLOGY 2008. [DOI: 10.5187/jast.2008.50.3.301] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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12
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Calcium, troponin, calmodulin, S100 proteins: From myocardial basics to new therapeutic strategies. Biochem Biophys Res Commun 2008; 369:247-64. [PMID: 17964289 DOI: 10.1016/j.bbrc.2007.10.082] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2007] [Accepted: 10/14/2007] [Indexed: 01/15/2023]
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13
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Liang B, Chung F, Qu Y, Pavlov D, Gillis TE, Tikunova SB, Davis JP, Tibbits GF. Familial hypertrophic cardiomyopathy-related cardiac troponin C mutation L29Q affects Ca2+ binding and myofilament contractility. Physiol Genomics 2008; 33:257-66. [PMID: 18285522 DOI: 10.1152/physiolgenomics.00154.2007] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The cardiac troponin C (cTnC) mutation, L29Q, has been found in a patient with familial hypertrophic cardiomyopathy. We previously showed that L29, together with neighboring residues, Asp2, Val28, and Gly30, plays an important role in determining the Ca(2+) affinity of site II, the regulatory site of mammalian cardiac troponin C (McTnC). Here we report on the Ca(2+) binding characteristics of L29Q McTnC and D2N/V28I/L29Q/G30D McTnC (NIQD) utilizing the Phe(27) --> Trp (F27W) substitution, allowing one to monitor Ca(2+) binding and release. We also studied the effect of these mutants on Ca(2+) activation of force generation in single mouse cardiac myocytes using cTnC replacement, together with sarcomere length (SL) dependence. The Ca(2+)-binding affinity of site II of L29Q McTnC(F27W) and NIQD McTnC(F27W) was approximately 1.3- and approximately 1.9-fold higher, respectively, than that of McTnC(F27W). The Ca(2+) disassociation rate from site II of L29Q McTnC(F27W) and NIQD McTnC(F27W) was not significantly different than that of control (McTnC(F27W)). However, the rate of Ca(2+) binding to site II was higher in L29Q McTnC(F27W) and NIQD McTnC(F27W) relative to control (approximately 1.5-fold and approximately 2.0-fold respectively). The Ca(2+) sensitivity of force generation was significantly higher in myocytes reconstituted with L29Q McTnC (approximately 1.4-fold) and NIQD McTnC (approximately 2-fold) compared with those reconstituted with McTnC. Interestingly, the change in Ca(2+) sensitivity of force generation in response to an SL change (1.9, 2.1, and 2.3 mum) was significantly reduced in myocytes containing L29Q McTnC or NIQD McTnC. These results demonstrate that the L29Q mutation enhances the Ca(2+)-binding characteristics of cTnC and that when incorporated into cardiac myocytes, this mutant alters myocyte contractility.
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Affiliation(s)
- Bo Liang
- Cardiac Membrane Research Laboratory, Kinesiology, Simon Fraser University, Burnaby, Canada
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Abstract
Cardiomyopathies are primary disorders of cardiac muscle associated with abnormalities of cardiac wall thickness, chamber size, contraction, relaxation, conduction, and rhythm. They are a major cause of morbidity and mortality at all ages and, like acquired forms of cardiovascular disease, often result in heart failure. Over the past two decades, molecular genetic studies of humans and analyses of model organisms have made remarkable progress in defining the pathogenesis of cardiomyopathies. Hypertrophic cardiomyopathy can result from mutations in 11 genes that encode sarcomere proteins, and dilated cardiomyopathy is caused by mutations at 25 chromosome loci where genes encoding contractile, cytoskeletal, and calcium regulatory proteins have been identified. Causes of cardiomyopathies associated with clinically important cardiac arrhythmias have also been discovered: Mutations in cardiac metabolic genes cause hypertrophy in association with ventricular pre-excitation and mutations causing arrhythmogenic right ventricular dysplasia were recently discovered in protein constituents of desmosomes. This considerable genetic heterogeneity suggests that there are multiple pathways that lead to changes in heart structure and function. Defects in myocyte force generation, force transmission, and calcium homeostasis have emerged as particularly critical signals driving these pathologies. Delineation of the cell and molecular events triggered by cardiomyopathy gene mutations provide new fundamental knowledge about myocyte biology and organ physiology that accounts for cardiac remodeling and defines mechanistic pathways that lead to heart failure.
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Affiliation(s)
- Ferhaan Ahmad
- Cardiovascular Institute and Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15213, USA
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Shishkin SS, Kovalyov LI, Kovalyova MA. Proteomic studies of human and other vertebrate muscle proteins. BIOCHEMISTRY (MOSCOW) 2004; 69:1283-98. [PMID: 15627382 DOI: 10.1007/s10541-005-0074-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
This review summarizes results of some systemic studies of muscle proteins of humans and some other vertebrates. The studies, started after introduction of two-dimensional gel electrophoresis of O'Farrell, were significantly extended during development of proteomics, a special branch of functional genomics. Special attention is paid to analysis of characteristic features of strategy for practical realization of the systemic approach during three main stages of these studies: pre-genomic, genomic (with organizational registration of proteomics), and post-genomic characterized by active use of structural genomics data. Proteomic technologies play an important role in detection of changes in isoforms of various muscle proteins (myosins, troponins, etc.). These changes possibly reflecting tissue specificity of gene expression may underline functional state of muscle tissues under normal and pathological conditions, and such proteomic analysis is now used in various fields of medicine.
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Affiliation(s)
- S S Shishkin
- Bach Institute of Biochemistry, Russian Academy of Sciences, Moscow 119071, Russia.
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Proteomic studies of human and other vertebrate muscle proteins. BIOCHEMISTRY (MOSCOW) 2004. [DOI: 10.1007/pl00021771] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/09/2023]
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Adhikari BB, Wang K. Interplay of troponin- and Myosin-based pathways of calcium activation in skeletal and cardiac muscle: the use of W7 as an inhibitor of thin filament activation. Biophys J 2004; 86:359-70. [PMID: 14695278 PMCID: PMC1303801 DOI: 10.1016/s0006-3495(04)74112-0] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
Abstract
To investigate the interplay between the thin and thick filaments during calcium activation in striated muscle, we employed n-(6-aminohexyl) 5-chloro-1-napthalenesulfonamide (W7) as an inhibitor of troponin C and compared its effects with that of the myosin-specific inhibitor, 2,3-butanedione 2-monoxime (BDM). In both skeletal and cardiac fibers, W7 reversibly inhibited ATPase and tension over the full range of calcium activation between pCa 8.0 and 4.5, resulting in reduced calcium sensitivity and cooperativity of ATPase and tension activations. At maximal activation in skeletal fibers, the W7 concentrations for half-maximal inhibition (KI) were 70-80 micro M for ATPase and 20-30 micro M for tension, nearly >200-fold lower than BDM (20 mM and 5-8 mM, respectively). When W7 (50 microM) and BDM (20 mM) were combined in skeletal fibers, the ATPase and tension-pCa curves exhibited lower apparent cooperativity and maxima and higher calcium sensitivity than expected from two independent activation pathways, suggesting that the interplay between the thin and thick filaments varies with the level of activation. Significantly, the inhibition of W7 increased the ATPase/tension ratio during activation in both muscle types. W7 holds much promise as a potent and reversible inhibitor of thin filament-mediated calcium activation of skeletal and cardiac muscle contraction.
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Affiliation(s)
- Bishow B Adhikari
- Muscle Proteomics and Nanotechnology Section, Laboratory of Muscle Biology, National Institutes of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA
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Szczesna-Cordary D, Guzman G, Ng SS, Zhao J. Familial Hypertrophic Cardiomyopathy-linked Alterations in Ca2+ Binding of Human Cardiac Myosin Regulatory Light Chain Affect Cardiac Muscle Contraction. J Biol Chem 2004; 279:3535-42. [PMID: 14594949 DOI: 10.1074/jbc.m307092200] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The ventricular isoform of human cardiac regulatory light chain (HCRLC) has been shown to be one of the sarcomeric proteins associated with familial hypertrophic cardiomyopathy (FHC), an autosomal dominant disease characterized by left ventricular and/or septal hypertrophy, myofibrillar disarray, and sudden cardiac death. Our recent studies have demonstrated that the properties of isolated HCRLC could be significantly altered by the FHC mutations and that their detrimental effects depend upon the specific position of the missense mutation. This report reveals that the Ca(2+) sensitivity of myofibrillar ATPase activity and steady-state force development are also likely to change with the location of the specific FHC HCRLC mutation. The largest effect was seen for the two FHC mutations, N47K and R58Q, located directly in or near the single Ca(2+)-Mg(2+) binding site of HCRLC, which demonstrated no Ca(2+) binding compared with wild-type and other FHC mutants (A13T, F18L, E22K, P95A). These two mutants when reconstituted in porcine cardiac muscle preparations increased Ca(2+) sensitivity of myofibrillar ATPase activity and force development. These results suggest the importance of the intact Ca(2+) binding site of HCRLC in the regulation of cardiac muscle contraction and imply its possible role in the regulatory light chain-linked pathogenesis of FHC.
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Affiliation(s)
- Danuta Szczesna-Cordary
- Department of Molecular and Cellular Pharmacology, University of Miami School of Medicine, Miami, Florida 33136, USA.
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