1
|
Hilderink S, Schuldt M, Goebel M, Jansen VJ, Manders E, Moorman S, Dorsch LM, van Steenbeek FG, van der Velden J, Kuster DWD. Characterization of heterozygous and homozygous mouse models with the most common hypertrophic cardiomyopathy mutation MYBPC3 c.2373InsG in the Netherlands. J Mol Cell Cardiol 2023; 185:65-76. [PMID: 37844837 DOI: 10.1016/j.yjmcc.2023.10.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/25/2023] [Revised: 09/25/2023] [Accepted: 10/11/2023] [Indexed: 10/18/2023]
Abstract
Hypertrophic cardiomyopathy (HCM) is frequently caused by mutations in the cardiac myosin binding protein-C (cMyBP-C) encoding gene MYBPC3. In the Netherlands, approximately 25% of patients carry the MYBPC3c.2373InsG founder mutation. Most patients are heterozygous (MYBPC3+/InsG) and have highly variable phenotypic expression, whereas homozygous (MYBPC3InsG/InsG) patients have severe HCM at a young age. To improve understanding of disease progression and genotype-phenotype relationship based on the hallmarks of human HCM, we characterized mice with CRISPR/Cas9-induced heterozygous and homozygous mutations. At 18-28 weeks of age, we assessed the cardiac phenotype of Mybpc3+/InsG and Mybpc3InsG/InsG mice with echocardiography, and performed histological analyses. Cytoskeletal proteins and cardiomyocyte contractility of 3-4 week old and 18-28 week old Mybpc3c.2373InsG mice were compared to wild-type (WT) mice. Expectedly, knock-in of Mybpc3c.2373InsG resulted in the absence of cMyBP-C and our 18-28 week old homozygous Mybpc3c.2373InsG model developed cardiac hypertrophy and severe left ventricular systolic and diastolic dysfunction, whereas HCM was not evident in Mybpc3+/InsG mice. Mybpc3InsG/InsG cardiomyocytes also presented with slowed contraction-relaxation kinetics, to a greater extent in 18-28 week old mice, partially due to increased levels of detyrosinated tubulin and desmin, and reduced cardiac troponin I (cTnI) phosphorylation. Impaired cardiomyocyte contraction-relaxation kinetics were successfully normalized in 18-28 week old Mybpc3InsG/InsG cardiomyocytes by combining detyrosination inhibitor parthenolide and β-adrenergic receptor agonist isoproterenol. Both the 3-4 week old and 18-28 week old Mybpc3InsG/InsG models recapitulate HCM, with a severe phenotype present in the 18-28 week old model.
Collapse
Affiliation(s)
- Sarah Hilderink
- Amsterdam UMC Location Vrije Universiteit Amsterdam, Physiology, De Boelelaan 1118, Amsterdam, the Netherlands; Amsterdam Cardiovascular Sciences, Heart Failure & Arrhythmias, Amsterdam, the Netherlands
| | - Maike Schuldt
- Amsterdam UMC Location Vrije Universiteit Amsterdam, Physiology, De Boelelaan 1118, Amsterdam, the Netherlands; Amsterdam Cardiovascular Sciences, Heart Failure & Arrhythmias, Amsterdam, the Netherlands
| | - Max Goebel
- Amsterdam UMC Location Vrije Universiteit Amsterdam, Physiology, De Boelelaan 1118, Amsterdam, the Netherlands; Amsterdam Cardiovascular Sciences, Heart Failure & Arrhythmias, Amsterdam, the Netherlands
| | - Valentijn J Jansen
- Amsterdam UMC Location Vrije Universiteit Amsterdam, Physiology, De Boelelaan 1118, Amsterdam, the Netherlands; Amsterdam Cardiovascular Sciences, Heart Failure & Arrhythmias, Amsterdam, the Netherlands
| | - Emmy Manders
- Amsterdam UMC Location Vrije Universiteit Amsterdam, Physiology, De Boelelaan 1118, Amsterdam, the Netherlands
| | - Stan Moorman
- Amsterdam UMC Location Vrije Universiteit Amsterdam, Physiology, De Boelelaan 1118, Amsterdam, the Netherlands; Amsterdam Cardiovascular Sciences, Heart Failure & Arrhythmias, Amsterdam, the Netherlands
| | - Larissa M Dorsch
- Amsterdam UMC Location Vrije Universiteit Amsterdam, Physiology, De Boelelaan 1118, Amsterdam, the Netherlands; Amsterdam Cardiovascular Sciences, Heart Failure & Arrhythmias, Amsterdam, the Netherlands
| | - Frank G van Steenbeek
- Department of Clinical Sciences, Faculty of Veterinary Medicine, Utrecht University, 3584 CL Utrecht, the Netherlands; Department of Cardiology, Division Heart & Lungs, University Medical Center Utrecht, Utrecht University, 3508 GA Utrecht, the Netherlands; Regenerative Medicine Center Utrecht, University Medical Center Utrecht, Utrecht University, 3584 CT Utrecht, the Netherlands
| | - Jolanda van der Velden
- Amsterdam UMC Location Vrije Universiteit Amsterdam, Physiology, De Boelelaan 1118, Amsterdam, the Netherlands; Amsterdam Cardiovascular Sciences, Heart Failure & Arrhythmias, Amsterdam, the Netherlands
| | - Diederik W D Kuster
- Amsterdam UMC Location Vrije Universiteit Amsterdam, Physiology, De Boelelaan 1118, Amsterdam, the Netherlands; Amsterdam Cardiovascular Sciences, Heart Failure & Arrhythmias, Amsterdam, the Netherlands.
| |
Collapse
|
2
|
Hanft LM, Robinett JC, Kalogeris TJ, Campbell KS, Biesiadecki BJ, McDonald KS. Thin filament regulation of cardiac muscle power output: Implications for targets to improve human failing hearts. J Gen Physiol 2023; 155:e202213290. [PMID: 37000170 PMCID: PMC10067705 DOI: 10.1085/jgp.202213290] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Revised: 02/14/2023] [Accepted: 03/13/2023] [Indexed: 04/01/2023] Open
Abstract
The heart's pumping capacity is determined by myofilament power generation. Power is work done per unit time and measured as the product of force and velocity. At a sarcomere level, these contractile properties are linked to the number of attached cross-bridges and their cycling rate, and many signaling pathways modulate one or both factors. We previously showed that power is increased in rodent permeabilized cardiac myocytes following PKA-mediated phosphorylation of myofibrillar proteins. The current study found that that PKA increased power by ∼30% in permeabilized cardiac myocyte preparations (n = 8) from human failing hearts. To address myofilament molecular specificity of PKA effects, mechanical properties were measured in rat permeabilized slow-twitch skeletal muscle fibers before and after exchange of endogenous slow skeletal troponin with recombinant human Tn complex that contains cardiac (c)TnT, cTnC and either wildtype (WT) cTnI or pseudo-phosphorylated cTnI at sites Ser23/24Asp, Tyr26Glu, or the combinatorial Ser23/24Asp and Tyr26Glu. We found that cTnI Ser23/24Asp, Tyr26Glu, and combinatorial Ser23/24Asp and Tyr26Glu were sufficient to increase power by ∼20%. Next, we determined whether pseudo-phosphorylated cTnI at Ser23/24 was sufficient to increase power in cardiac myocytes from human failing hearts. Following cTn exchange that included cTnI Ser23/24Asp, power output increased ∼20% in permeabilized cardiac myocyte preparations (n = 6) from the left ventricle of human failing hearts. These results implicate cTnI N-terminal phosphorylation as a molecular regulator of myocyte power and could serve as a regional target for small molecule therapy to unmask myocyte power reserve capacity in human failing hearts.
Collapse
Affiliation(s)
- Laurin M. Hanft
- Department of Medical Pharmacology and Physiology, School of Medicine, University of Missouri, Columbia, MO, USA
| | - Joel C. Robinett
- Department of Medical Pharmacology and Physiology, School of Medicine, University of Missouri, Columbia, MO, USA
| | - Theodore J. Kalogeris
- Department of Medical Pharmacology and Physiology, School of Medicine, University of Missouri, Columbia, MO, USA
| | - Kenneth S. Campbell
- Department of Physiology and Division of Cardiovascular Medicine, University of Kentucky, Lexington, KY, USA
| | | | - Kerry S. McDonald
- Department of Medical Pharmacology and Physiology, School of Medicine, University of Missouri, Columbia, MO, USA
| |
Collapse
|
3
|
Salhi HE, Shettigar V, Salyer L, Sturgill S, Brundage EA, Robinett J, Xu Z, Abay E, Lowe J, Janssen PML, Rafael-Fortney JA, Weisleder N, Ziolo MT, Biesiadecki BJ. The lack of Troponin I Ser-23/24 phosphorylation is detrimental to in vivo cardiac function and exacerbates cardiac disease. J Mol Cell Cardiol 2023; 176:84-96. [PMID: 36724829 PMCID: PMC10074981 DOI: 10.1016/j.yjmcc.2023.01.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Revised: 01/11/2023] [Accepted: 01/24/2023] [Indexed: 01/30/2023]
Abstract
Troponin I (TnI) is a key regulator of cardiac contraction and relaxation with TnI Ser-23/24 phosphorylation serving as a myofilament mechanism to modulate cardiac function. Basal cardiac TnI Ser-23/24 phosphorylation is high such that both increased and decreased TnI phosphorylation may modulate cardiac function. While the effects of increasing TnI Ser-23/24 phosphorylation on heart function are well established, the effects of decreasing TnI Ser-23/24 phosphorylation are not clear. To understand the in vivo role of decreased TnI Ser-23/24 phosphorylation, mice expressing TnI with Ser-23/24 mutated to alanine (TnI S23/24A) that lack the ability to be phosphorylated at these residues were subjected to echocardiography and pressure-volume hemodynamic measurements in the absence or presence of physiological (pacing increasing heart rate or adrenergic stimulation) or pathological (transverse aortic constriction (TAC)) stress. In the absence of pathological stress, the lack of TnI Ser-23/24 phosphorylation impaired systolic and diastolic function. TnI S23/24A mice also had an impaired systolic and diastolic response upon stimulation increased heart rate and an impaired adrenergic response upon dobutamine infusion. Following pathological cardiac stress induced by TAC, TnI S23/24A mice had a greater increase in ventricular mass, worse diastolic function, and impaired systolic and diastolic function upon increasing heart rate. These findings demonstrate that mice lacking the ability to phosphorylate TnI at Ser-23/24 have impaired in vivo systolic and diastolic cardiac function, a blunted cardiac reserve and a worse response to pathological stress supporting decreased TnI Ser23/24 phosphorylation is a modulator of these processes in vivo.
Collapse
Affiliation(s)
- Hussam E Salhi
- Department of Physiology and Cell Biology and Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH, United States of America
| | - Vikram Shettigar
- Department of Physiology and Cell Biology and Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH, United States of America
| | - Lorien Salyer
- Department of Physiology and Cell Biology and Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH, United States of America
| | - Sarah Sturgill
- Department of Physiology and Cell Biology and Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH, United States of America
| | - Elizabeth A Brundage
- Department of Physiology and Cell Biology and Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH, United States of America
| | - Joel Robinett
- Department of Physiology and Cell Biology and Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH, United States of America
| | - Zhaobin Xu
- Department of Physiology and Cell Biology and Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH, United States of America
| | - Eaman Abay
- Department of Physiology and Cell Biology and Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH, United States of America
| | - Jeovanna Lowe
- Department of Physiology and Cell Biology and Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH, United States of America
| | - Paul M L Janssen
- Department of Physiology and Cell Biology and Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH, United States of America
| | - Jill A Rafael-Fortney
- Department of Physiology and Cell Biology and Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH, United States of America
| | - Noah Weisleder
- Department of Physiology and Cell Biology and Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH, United States of America
| | - Mark T Ziolo
- Department of Physiology and Cell Biology and Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH, United States of America
| | - Brandon J Biesiadecki
- Department of Physiology and Cell Biology and Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH, United States of America.
| |
Collapse
|
4
|
Sevrieva IR, Ponnam S, Yan Z, Irving M, Kampourakis T, Sun YB. Phosphorylation-dependent interactions of myosin-binding protein C and troponin coordinate the myofilament response to protein kinase A. J Biol Chem 2023; 299:102767. [PMID: 36470422 PMCID: PMC9826837 DOI: 10.1016/j.jbc.2022.102767] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Revised: 11/23/2022] [Accepted: 11/24/2022] [Indexed: 12/12/2022] Open
Abstract
PKA-mediated phosphorylation of sarcomeric proteins enhances heart muscle performance in response to β-adrenergic stimulation and is associated with accelerated relaxation and increased cardiac output for a given preload. At the cellular level, the latter translates to a greater dependence of Ca2+ sensitivity and maximum force on sarcomere length (SL), that is, enhanced length-dependent activation. However, the mechanisms by which PKA phosphorylation of the most notable sarcomeric PKA targets, troponin I (cTnI) and myosin-binding protein C (cMyBP-C), lead to these effects remain elusive. Here, we specifically altered the phosphorylation level of cTnI in heart muscle cells and characterized the structural and functional effects at different levels of background phosphorylation of cMyBP-C and with two different SLs. We found Ser22/23 bisphosphorylation of cTnI was indispensable for the enhancement of length-dependent activation by PKA, as was cMyBP-C phosphorylation. This high level of coordination between cTnI and cMyBP-C may suggest coupling between their regulatory mechanisms. Further evidence for this was provided by our finding that cardiac troponin (cTn) can directly interact with cMyBP-C in vitro, in a phosphorylation- and Ca2+-dependent manner. In addition, bisphosphorylation at Ser22/Ser23 increased Ca2+ sensitivity at long SL in the presence of endogenously phosphorylated cMyBP-C. When cMyBP-C was dephosphorylated, bisphosphorylation of cTnI increased Ca2+ sensitivity and decreased cooperativity at both SLs, which may translate to deleterious effects in physiological settings. Our results could have clinical relevance for disease pathways, where PKA phosphorylation of cTnI may be functionally uncoupled from cMyBP-C phosphorylation due to mutations or haploinsufficiency.
Collapse
Affiliation(s)
- Ivanka R Sevrieva
- Randall Centre for Cell and Molecular Biophysics, and British Heart Foundation Centre of Research Excellence, King's College London, London, United Kingdom.
| | - Saraswathi Ponnam
- Randall Centre for Cell and Molecular Biophysics, and British Heart Foundation Centre of Research Excellence, King's College London, London, United Kingdom
| | - Ziqian Yan
- Randall Centre for Cell and Molecular Biophysics, and British Heart Foundation Centre of Research Excellence, King's College London, London, United Kingdom
| | - Malcolm Irving
- Randall Centre for Cell and Molecular Biophysics, and British Heart Foundation Centre of Research Excellence, King's College London, London, United Kingdom
| | - Thomas Kampourakis
- Randall Centre for Cell and Molecular Biophysics, and British Heart Foundation Centre of Research Excellence, King's College London, London, United Kingdom
| | - Yin-Biao Sun
- Randall Centre for Cell and Molecular Biophysics, and British Heart Foundation Centre of Research Excellence, King's College London, London, United Kingdom
| |
Collapse
|
5
|
Gömöri K, Herwig M, Budde H, Hassoun R, Mostafi N, Zhazykbayeva S, Sieme M, Modi S, Szabados T, Pipis J, Farkas-Morvay N, Leprán I, Ágoston G, Baczkó I, Kovács Á, Mügge A, Ferdinandy P, Görbe A, Bencsik P, Hamdani N. Ca2+/calmodulin-dependent protein kinase II and protein kinase G oxidation contributes to impaired sarcomeric proteins in hypertrophy model. ESC Heart Fail 2022; 9:2585-2600. [PMID: 35584900 PMCID: PMC9288768 DOI: 10.1002/ehf2.13973] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Revised: 04/20/2022] [Accepted: 05/04/2022] [Indexed: 11/24/2022] Open
Abstract
Aims Volume overload (VO) induced hypertrophy is one of the hallmarks to the development of heart diseases. Understanding the compensatory mechanisms involved in this process might help preventing the disease progression. Methods and results Therefore, the present study used 2 months old Wistar rats, which underwent an aortocaval fistula to develop VO‐induced hypertrophy. The animals were subdivided into four different groups, two sham operated animals served as age‐matched controls and two groups with aortocaval fistula. Echocardiography was performed prior termination after 4‐ and 8‐month. Functional and molecular changes of several sarcomeric proteins and their signalling pathways involved in the regulation and modulation of cardiomyocyte function were investigated. Results The model was characterized with preserved ejection fraction in all groups and with elevated heart/body weight ratio, left/right ventricular and atrial weight at 4‐ and 8‐month, which indicates VO‐induced hypertrophy. In addition, 8‐months groups showed increased left ventricular internal diameter during diastole, RV internal diameter, stroke volume and velocity‐time index compared with their age‐matched controls. These changes were accompanied by increased Ca2+ sensitivity and titin‐based cardiomyocyte stiffness in 8‐month VO rats compared with other groups. The altered cardiomyocyte mechanics was associated with phosphorylation deficit of sarcomeric proteins cardiac troponin I, myosin binding protein C and titin, also accompanied with impaired signalling pathways involved in phosphorylation of these sarcomeric proteins in 8‐month VO rats compared with age‐matched control group. Impaired protein phosphorylation status and dysregulated signalling pathways were associated with significant alterations in the oxidative status of both kinases CaMKII and PKG explaining by this the elevated Ca2+ sensitivity and titin‐based cardiomyocyte stiffness and perhaps the development of hypertrophy. Conclusions Our findings showed VO‐induced cardiomyocyte dysfunction via deranged phosphorylation of myofilament proteins and signalling pathways due to increased oxidative state of CaMKII and PKG and this might contribute to the development of hypertrophy.
Collapse
Affiliation(s)
- Kamilla Gömöri
- Department of Pharmacology and Pharmacotherapy, University of Szeged, Szeged, Hungary.,Institut für Forschung und Lehre (IFL), Molecular and Experimental Cardiology, Ruhr University Bochum, Bochum, Germany.,Department of Pharmacology and Pharmacotherapy, Semmelweis University, Budapest, Hungary
| | - Melissa Herwig
- Institut für Forschung und Lehre (IFL), Molecular and Experimental Cardiology, Ruhr University Bochum, Bochum, Germany.,Department of Cardiology, St. Josef-Hospital, Ruhr University Bochum, Bochum, Germany
| | - Heidi Budde
- Institut für Forschung und Lehre (IFL), Molecular and Experimental Cardiology, Ruhr University Bochum, Bochum, Germany.,Department of Cardiology, St. Josef-Hospital, Ruhr University Bochum, Bochum, Germany
| | - Roua Hassoun
- Institut für Forschung und Lehre (IFL), Molecular and Experimental Cardiology, Ruhr University Bochum, Bochum, Germany.,Department of Cardiology, St. Josef-Hospital, Ruhr University Bochum, Bochum, Germany
| | - Nusratul Mostafi
- Institut für Forschung und Lehre (IFL), Molecular and Experimental Cardiology, Ruhr University Bochum, Bochum, Germany.,Department of Cardiology, St. Josef-Hospital, Ruhr University Bochum, Bochum, Germany
| | - Saltanat Zhazykbayeva
- Institut für Forschung und Lehre (IFL), Molecular and Experimental Cardiology, Ruhr University Bochum, Bochum, Germany.,Department of Cardiology, St. Josef-Hospital, Ruhr University Bochum, Bochum, Germany
| | - Marcel Sieme
- Institut für Forschung und Lehre (IFL), Molecular and Experimental Cardiology, Ruhr University Bochum, Bochum, Germany.,Department of Cardiology, St. Josef-Hospital, Ruhr University Bochum, Bochum, Germany
| | - Suvasini Modi
- Institut für Forschung und Lehre (IFL), Molecular and Experimental Cardiology, Ruhr University Bochum, Bochum, Germany.,Department of Cardiology, St. Josef-Hospital, Ruhr University Bochum, Bochum, Germany
| | - Tamara Szabados
- Department of Pharmacology and Pharmacotherapy, University of Szeged, Szeged, Hungary.,Pharmahungary Group, Szeged, Hungary
| | - Judit Pipis
- Department of Pharmacology and Pharmacotherapy, University of Szeged, Szeged, Hungary.,Pharmahungary Group, Szeged, Hungary
| | | | - István Leprán
- Department of Pharmacology and Pharmacotherapy, University of Szeged, Szeged, Hungary
| | - Gergely Ágoston
- Institute of Family Medicine, University of Szeged, Szeged, Hungary
| | - István Baczkó
- Department of Pharmacology and Pharmacotherapy, University of Szeged, Szeged, Hungary
| | - Árpád Kovács
- Institut für Forschung und Lehre (IFL), Molecular and Experimental Cardiology, Ruhr University Bochum, Bochum, Germany.,Department of Cardiology, St. Josef-Hospital, Ruhr University Bochum, Bochum, Germany
| | - Andreas Mügge
- Department of Cardiology, St. Josef-Hospital, Ruhr University Bochum, Bochum, Germany
| | - Péter Ferdinandy
- Department of Pharmacology and Pharmacotherapy, Semmelweis University, Budapest, Hungary.,Pharmahungary Group, Szeged, Hungary
| | - Anikó Görbe
- Department of Pharmacology and Pharmacotherapy, University of Szeged, Szeged, Hungary.,Department of Pharmacology and Pharmacotherapy, Semmelweis University, Budapest, Hungary.,Pharmahungary Group, Szeged, Hungary
| | - Péter Bencsik
- Department of Pharmacology and Pharmacotherapy, University of Szeged, Szeged, Hungary.,Pharmahungary Group, Szeged, Hungary
| | - Nazha Hamdani
- Institut für Forschung und Lehre (IFL), Molecular and Experimental Cardiology, Ruhr University Bochum, Bochum, Germany.,Department of Pharmacology and Pharmacotherapy, Semmelweis University, Budapest, Hungary.,Department of Cardiology, St. Josef-Hospital, Ruhr University Bochum, Bochum, Germany.,HCEMM-Cardiovascular Research Group, Department of Pharmacology and Pharmacotherapy, Semmelweis University, Budapest, Hungary
| |
Collapse
|
6
|
Kwon HK, Choi H, Park SG, Park WJ, Kim, DH, Park ZY. Integrated Quantitative Phosphoproteomics and Cell-based Functional Screening Reveals Specific Pathological Cardiac Hypertrophy-related Phosphorylation Sites. Mol Cells 2021; 44:500-516. [PMID: 34158421 PMCID: PMC8334354 DOI: 10.14348/molcells.2021.4002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2019] [Accepted: 01/07/2019] [Indexed: 12/29/2022] Open
Abstract
Cardiac hypertrophic signaling cascades resulting in heart failure diseases are mediated by protein phosphorylation. Recent developments in mass spectrometry-based phosphoproteomics have led to the identification of thousands of differentially phosphorylated proteins and their phosphorylation sites. However, functional studies of these differentially phosphorylated proteins have not been conducted in a large-scale or high-throughput manner due to a lack of methods capable of revealing the functional relevance of each phosphorylation site. In this study, an integrated approach combining quantitative phosphoproteomics and cell-based functional screening using phosphorylation competition peptides was developed. A pathological cardiac hypertrophy model, junctate-1 transgenic mice and control mice, were analyzed using label-free quantitative phosphoproteomics to identify differentially phosphorylated proteins and sites. A cell-based functional assay system measuring hypertrophic cell growth of neonatal rat ventricle cardiomyocytes (NRVMs) following phenylephrine treatment was applied, and changes in phosphorylation of individual differentially phosphorylated sites were induced by incorporation of phosphorylation competition peptides conjugated with cell-penetrating peptides. Cell-based functional screening against 18 selected phosphorylation sites identified three phosphorylation sites (Ser-98, Ser-179 of Ldb3, and Ser-1146 of palladin) displaying near-complete inhibition of cardiac hypertrophic growth of NRVMs. Changes in phosphorylation levels of Ser-98 and Ser-179 in Ldb3 were further confirmed in NRVMs and other pathological/physiological hypertrophy models, including transverse aortic constriction and swimming models, using site-specific phospho-antibodies. Our integrated approach can be used to identify functionally important phosphorylation sites among differentially phosphorylated sites, and unlike conventional approaches, it is easily applicable for large-scale and/or high-throughput analyses.
Collapse
Affiliation(s)
- Hye Kyeong Kwon
- School of Life Sciences, Gwangju Institute of Science and Technology (GIST), Gwangju 61005, Korea
| | - Hyunwoo Choi
- School of Life Sciences, Gwangju Institute of Science and Technology (GIST), Gwangju 61005, Korea
| | - Sung-Gyoo Park
- School of Life Sciences, Gwangju Institute of Science and Technology (GIST), Gwangju 61005, Korea
| | - Woo Jin Park
- School of Life Sciences, Gwangju Institute of Science and Technology (GIST), Gwangju 61005, Korea
| | - Do Han Kim,
- School of Life Sciences, Gwangju Institute of Science and Technology (GIST), Gwangju 61005, Korea
| | - Zee-Yong Park
- School of Life Sciences, Gwangju Institute of Science and Technology (GIST), Gwangju 61005, Korea
| |
Collapse
|
7
|
Hanft LM, Fitzsimons DP, Hacker TA, Moss RL, McDonald KS. Cardiac MyBP-C phosphorylation regulates the Frank-Starling relationship in murine hearts. J Gen Physiol 2021; 153:e202012770. [PMID: 33646280 PMCID: PMC7927661 DOI: 10.1085/jgp.202012770] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Revised: 01/04/2021] [Accepted: 01/26/2021] [Indexed: 01/08/2023] Open
Abstract
The Frank-Starling relationship establishes that elevated end-diastolic volume progressively increases ventricular pressure and stroke volume in healthy hearts. The relationship is modulated by a number of physiological inputs and is often depressed in human heart failure. Emerging evidence suggests that cardiac myosin-binding protein-C (cMyBP-C) contributes to the Frank-Starling relationship. We measured contractile properties at multiple levels of structural organization to determine the role of cMyBP-C and its phosphorylation in regulating (1) the sarcomere length dependence of power in cardiac myofilaments and (2) the Frank-Starling relationship in vivo. We compared transgenic mice expressing wild-type cMyBP-C on the null background, which have ∼50% phosphorylated cMyBP-C (Controls), to transgenic mice lacking cMyBP-C (KO) and to mice expressing cMyBP-C that have serine-273, -282, and -302 mutated to aspartate (cMyBP-C t3SD) or alanine (cMyBP-C t3SA) on the null background to mimic either constitutive PKA phosphorylation or nonphosphorylated cMyBP-C, respectively. We observed a continuum of length dependence of power output in myocyte preparations. Sarcomere length dependence of power progressively increased with a rank ordering of cMyBP-C KO = cMyBP-C t3SA < Control < cMyBP-C t3SD. Length dependence of myofilament power translated, at least in part, to hearts, whereby Frank-Starling relationships were steepest in cMyBP-C t3SD mice. The results support the hypothesis that cMyBP-C and its phosphorylation state tune sarcomere length dependence of myofibrillar power, and these regulatory processes translate across spatial levels of myocardial organization to control beat-to-beat ventricular performance.
Collapse
Affiliation(s)
- Laurin M. Hanft
- Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, MO
| | - Daniel P. Fitzsimons
- Department of Cell and Regenerative Biology, University of Wisconsin-Madison, Madison, WI
| | - Timothy A. Hacker
- Department of Medicine, University of Wisconsin-Madison, Madison, WI
| | - Richard L. Moss
- Department of Cell and Regenerative Biology, University of Wisconsin-Madison, Madison, WI
| | - Kerry S. McDonald
- Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, MO
| |
Collapse
|
8
|
Genetic Restrictive Cardiomyopathy: Causes and Consequences-An Integrative Approach. Int J Mol Sci 2021; 22:ijms22020558. [PMID: 33429969 PMCID: PMC7827163 DOI: 10.3390/ijms22020558] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Revised: 01/05/2021] [Accepted: 01/06/2021] [Indexed: 12/12/2022] Open
Abstract
The sarcomere as the smallest contractile unit is prone to alterations in its functional, structural and associated proteins. Sarcomeric dysfunction leads to heart failure or cardiomyopathies like hypertrophic (HCM) or restrictive cardiomyopathy (RCM) etc. Genetic based RCM, a very rare but severe disease with a high mortality rate, might be induced by mutations in genes of non-sarcomeric, sarcomeric and sarcomere associated proteins. In this review, we discuss the functional effects in correlation to the phenotype and present an integrated model for the development of genetic RCM.
Collapse
|
9
|
Vikhorev PG, Vikhoreva NN, Yeung W, Li A, Lal S, dos Remedios CG, Blair CA, Guglin M, Campbell KS, Yacoub MH, de Tombe P, Marston SB. Titin-truncating mutations associated with dilated cardiomyopathy alter length-dependent activation and its modulation via phosphorylation. Cardiovasc Res 2020; 118:241-253. [PMID: 33135063 PMCID: PMC8752363 DOI: 10.1093/cvr/cvaa316] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/08/2019] [Accepted: 10/20/2020] [Indexed: 12/18/2022] Open
Abstract
Abstract
Aims
Dilated cardiomyopathy (DCM) is associated with mutations in many genes encoding sarcomere proteins. Truncating mutations in the titin gene TTN are the most frequent. Proteomic and functional characterizations are required to elucidate the origin of the disease and the pathogenic mechanisms of TTN-truncating variants.
Methods and results
We isolated myofibrils from DCM hearts carrying truncating TTN mutations and measured the Ca2+ sensitivity of force and its length dependence. Simultaneous measurement of force and adenosine triphosphate (ATP) consumption in skinned cardiomyocytes was also performed. Phosphorylation levels of troponin I (TnI) and myosin binding protein-C (MyBP-C) were manipulated using protein kinase A and λ phosphatase. mRNA sequencing was employed to overview gene expression profiles. We found that Ca2+ sensitivity of myofibrils carrying TTN mutations was significantly higher than in myofibrils from donor hearts. The length dependence of the Ca2+ sensitivity was absent in DCM myofibrils with TTN-truncating variants. No significant difference was found in the expression level of TTN mRNA between the DCM and donor groups. TTN exon usage and splicing were also similar. However, we identified down-regulation of genes encoding Z-disk proteins, while the atrial-specific regulatory myosin light chain gene, MYL7, was up-regulated in DCM patients with TTN-truncating variants.
Conclusion
Titin-truncating mutations lead to decreased length-dependent activation and increased elasticity of myofibrils. Phosphorylation levels of TnI and MyBP-C seen in the left ventricles are essential for the length-dependent changes in Ca2+ sensitivity in healthy donors, but they are reduced in DCM patients with TTN-truncating variants. A decrease in expression of Z-disk proteins may explain the observed decrease in myofibril passive stiffness and length-dependent activation.
Collapse
Affiliation(s)
- Petr G Vikhorev
- National Heart and Lung Institute, Imperial College London, Du Cane Road, London W12 0NN, UK
| | - Natalia N Vikhoreva
- Heart Science Centre, Magdi Yacoub Institute, Harefield Hospital, London UB9 6JH, UK
| | - WaiChun Yeung
- National Heart and Lung Institute, Imperial College London, Du Cane Road, London W12 0NN, UK
| | - Amy Li
- Department of Pharmacy and Biomedical Sciences, La Trobe University, Bendigo, VIC 3550, Australia
| | - Sean Lal
- School of Medical Sciences, Faculty of Medicine and Health, University of Sydney, NSW 2006, Australia
| | - Cristobal G dos Remedios
- Division of Molecular Cardiology and Biophysics, Victor Chang Cardiac Research Institute, Darlinghurst, NSW 2010, Australia
| | - Cheavar A Blair
- Division of Cardiovascular Medicine, Department of Physiology, University of Kentucky, Lexington, KY, USA
| | - Maya Guglin
- Division of Cardiovascular Medicine, Department of Physiology, University of Kentucky, Lexington, KY, USA
| | - Kenneth S Campbell
- Division of Cardiovascular Medicine, Department of Physiology, University of Kentucky, Lexington, KY, USA
| | - Magdi H Yacoub
- National Heart and Lung Institute, Imperial College London, Du Cane Road, London W12 0NN, UK
| | - Pieter de Tombe
- National Heart and Lung Institute, Imperial College London, Du Cane Road, London W12 0NN, UK
- Heart Science Centre, Magdi Yacoub Institute, Harefield Hospital, London UB9 6JH, UK
- Department of Physiology and Biophysics, University of Illinois at Chicago, Chicago, IL, USA
| | - Steven B Marston
- National Heart and Lung Institute, Imperial College London, Du Cane Road, London W12 0NN, UK
| |
Collapse
|
10
|
Blair CA, Brundage EA, Thompson KL, Stromberg A, Guglin M, Biesiadecki BJ, Campbell KS. Heart Failure in Humans Reduces Contractile Force in Myocardium From Both Ventricles. JACC Basic Transl Sci 2020; 5:786-798. [PMID: 32875169 PMCID: PMC7452203 DOI: 10.1016/j.jacbts.2020.05.014] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Revised: 05/18/2020] [Accepted: 05/18/2020] [Indexed: 01/01/2023]
Abstract
Contractile assays were performed using multicellular preparations isolated from the left and right ventricles of organ donors and patients with heart failure. Heart failure reduced maximum force and power by approximately 30% in the myocardium from both ventricles. Heart failure increased the Ca2+ sensitivity of contraction, but the effect was bigger in right ventricular tissue than in left ventricular samples. The changes in Ca2+ sensitivity may reflect ventricle-specific post-translational modifications to sarcomeric proteins.
This study measured how heart failure affects the contractile properties of the human myocardium from the left and right ventricles. The data showed that maximum force and maximum power were reduced by approximately 30% in multicellular preparations from both ventricles, possibly because of ventricular remodeling (e.g., cellular disarray and/or excess fibrosis). Heart failure increased the calcium (Ca2+) sensitivity of contraction in both ventricles, but the effect was bigger in right ventricular samples. The changes in Ca2+ sensitivity were associated with ventricle-specific changes in the phosphorylation of troponin I, which indicated that adrenergic stimulation might induce different effects in the left and right ventricles.
Collapse
Key Words
- Ca2+ sensitivity
- Ca2+, calcium
- Fact, maximum Ca2+-activated force
- Fpas, passive force
- LV, left ventricle
- MyBP-C, myosin binding protein-C
- PKA, protein kinase A
- Pmax, maximum power output
- RLC, regulatory light chain
- RV, right ventricle
- TnI, troponin I
- Vmax, maximum shortening velocity
- heart failure
- human myocardium
- ktr, rate of force recovery
- myofilament proteins
- nH, Hill coefficient
- ventricular function
Collapse
Affiliation(s)
- Cheavar A Blair
- Department of Physiology, University of Kentucky, Lexington, Kentucky
| | - Elizabeth A Brundage
- Department of Physiology and Cell Biology and The Davis Heart and Lung Research Institute, The Ohio State University, Columbus, Ohio
| | | | - Arnold Stromberg
- Department of Statistics, University of Kentucky, Lexington, Kentucky
| | - Maya Guglin
- Division of Cardiovascular Medicine, University of Kentucky, Lexington, Kentucky
| | - Brandon J Biesiadecki
- Department of Physiology and Cell Biology and The Davis Heart and Lung Research Institute, The Ohio State University, Columbus, Ohio
| | - Kenneth S Campbell
- Department of Physiology, University of Kentucky, Lexington, Kentucky.,Division of Cardiovascular Medicine, University of Kentucky, Lexington, Kentucky
| |
Collapse
|
11
|
McDonald KS, Hanft LM, Robinett JC, Guglin M, Campbell KS. Regulation of Myofilament Contractile Function in Human Donor and Failing Hearts. Front Physiol 2020; 11:468. [PMID: 32523542 PMCID: PMC7261867 DOI: 10.3389/fphys.2020.00468] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Accepted: 04/16/2020] [Indexed: 01/14/2023] Open
Abstract
Heart failure (HF) often includes changes in myocardial contractile function. This study addressed the myofibrillar basis for contractile dysfunction in failing human myocardium. Regulation of contractile properties was measured in cardiac myocyte preparations isolated from frozen, left ventricular mid-wall biopsies of donor (n = 7) and failing human hearts (n = 8). Permeabilized cardiac myocyte preparations were attached between a force transducer and a position motor, and both the Ca2+ dependence and sarcomere length (SL) dependence of force, rate of force, loaded shortening, and power output were measured at 15 ± 1°C. The myocyte preparation size was similar between groups (donor: length 148 ± 10 μm, width 21 ± 2 μm, n = 13; HF: length 131 ± 9 μm, width 23 ± 1 μm, n = 16). The maximal Ca2+-activated isometric force was also similar between groups (donor: 47 ± 4 kN⋅m-2; HF: 44 ± 5 kN⋅m-2), which implicates that previously reported force declines in multi-cellular preparations reflect, at least in part, tissue remodeling. Maximal force development rates were also similar between groups (donor: k tr = 0.60 ± 0.05 s-1; HF: k tr = 0.55 ± 0.04 s-1), and both groups exhibited similar Ca2+ activation dependence of k tr values. Human cardiac myocyte preparations exhibited a Ca2+ activation dependence of loaded shortening and power output. The peak power output normalized to isometric force (PNPO) decreased by ∼12% from maximal Ca2+ to half-maximal Ca2+ activations in both groups. Interestingly, the SL dependence of PNPO was diminished in failing myocyte preparations. During sub-maximal Ca2+ activation, a reduction in SL from ∼2.25 to ∼1.95 μm caused a ∼26% decline in PNPO in donor myocytes but only an ∼11% change in failing myocytes. These results suggest that altered length-dependent regulation of myofilament function impairs ventricular performance in failing human hearts.
Collapse
Affiliation(s)
- Kerry S. McDonald
- Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, MO, United States
| | - Laurin M. Hanft
- Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, MO, United States
| | - Joel C. Robinett
- Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, MO, United States
| | - Maya Guglin
- Division of Cardiovascular Medicine, University of Kentucky, Lexington, KY, United States
| | - Kenneth S. Campbell
- Division of Cardiovascular Medicine, University of Kentucky, Lexington, KY, United States
- Department of Physiology, University of Kentucky, Lexington, KY, United States
| |
Collapse
|
12
|
Cimiotti D, Fujita-Becker S, Möhner D, Smolina N, Budde H, Wies A, Morgenstern L, Gudkova A, Sejersen T, Sjöberg G, Mügge A, Nowaczyk MM, Reusch P, Pfitzer G, Stehle R, Schröder RR, Mannherz HG, Kostareva A, Jaquet K. Infantile restrictive cardiomyopathy: cTnI-R170G/W impair the interplay of sarcomeric proteins and the integrity of thin filaments. PLoS One 2020; 15:e0229227. [PMID: 32182250 PMCID: PMC7077804 DOI: 10.1371/journal.pone.0229227] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2019] [Accepted: 01/31/2020] [Indexed: 12/11/2022] Open
Abstract
TNNI3 encoding cTnI, the inhibitory subunit of the troponin complex, is the main target for mutations leading to restrictive cardiomyopathy (RCM). Here we investigate two cTnI-R170G/W amino acid replacements, identified in infantile RCM patients, which are located in the regulatory C-terminus of cTnI. The C-terminus is thought to modulate the function of the inhibitory region of cTnI. Both cTnI-R170G/W strongly enhanced the Ca2+-sensitivity of skinned fibres, as is typical for RCM-mutations. Both mutants strongly enhanced the affinity of troponin (cTn) to tropomyosin compared to wildtype cTn, whereas binding to actin was either strengthened (R170G) or weakened (R170W). Furthermore, the stability of reconstituted thin filaments was reduced as revealed by electron microscopy. Filaments containing R170G/W appeared wavy and showed breaks. Decoration of filaments with myosin subfragment S1 was normal in the presence of R170W, but was irregular with R170G. Surprisingly, both mutants did not affect the Ca2+-dependent activation of reconstituted cardiac thin filaments. In the presence of the N-terminal fragment of cardiac myosin binding protein C (cMyBPC-C0C2) cooperativity of thin filament activation was increased only when the filaments contained wildtype cTn. No effect was observed in the presence of cTn containing R170G/W. cMyBPC-C0C2 significantly reduced binding of wildtype troponin to actin/tropomyosin, but not of both mutant cTn. Moreover, we found a direct troponin/cMyBPC-C0C2 interaction using microscale thermophoresis and identified cTnI and cTnT, but not cTnC as binding partners for cMyBPC-C0C2. Only cTn containing cTnI-R170G showed a reduced affinity towards cMyBPC-C0C2. Our results suggest that the RCM cTnI variants R170G/W impair the communication between thin and thick filament proteins and destabilize thin filaments.
Collapse
Affiliation(s)
- Diana Cimiotti
- Department of Clinical Pharmacology and Molecular Cardiology, Ruhr-University of Bochum, Bochum, Germany.,Cardiology, Bergmannsheil and St. Josef Hospital, Clinics of the Ruhr-University Bochum, Bochum, Germany
| | - Setsuko Fujita-Becker
- Cryoelectron Microscopy, BioQuant, Medical Faculty, University of Heidelberg, Heidelberg, Germany
| | - Desirée Möhner
- Vegetative Physiology, University of Cologne, Cologne, Germany
| | - Natalia Smolina
- Department of Molecular Biology and Genetics, Almazov Federal Medical Research Center, St. Petersburg, Russia
| | - Heidi Budde
- Department of Clinical Pharmacology and Molecular Cardiology, Ruhr-University of Bochum, Bochum, Germany.,Cardiology, Bergmannsheil and St. Josef Hospital, Clinics of the Ruhr-University Bochum, Bochum, Germany
| | - Aline Wies
- Vegetative Physiology, University of Cologne, Cologne, Germany
| | - Lisa Morgenstern
- Department of Clinical Pharmacology and Molecular Cardiology, Ruhr-University of Bochum, Bochum, Germany.,Cardiology, Bergmannsheil and St. Josef Hospital, Clinics of the Ruhr-University Bochum, Bochum, Germany
| | - Alexandra Gudkova
- Department of Molecular Biology and Genetics, Almazov Federal Medical Research Center, St. Petersburg, Russia
| | - Thomas Sejersen
- Department of Women's and Children's Health and Center for Molecular Medicine, Karolinska Institute, Stockholm, Sweden
| | - Gunnar Sjöberg
- Department of Women's and Children's Health and Center for Molecular Medicine, Karolinska Institute, Stockholm, Sweden
| | - Andreas Mügge
- Cardiology, Bergmannsheil and St. Josef Hospital, Clinics of the Ruhr-University Bochum, Bochum, Germany
| | - Marc M Nowaczyk
- Plant Biochemistry, Faculty of Biology and Biotechnology, Ruhr-University Bochum, Bochum, Germany
| | - Peter Reusch
- Department of Clinical Pharmacology and Molecular Cardiology, Ruhr-University of Bochum, Bochum, Germany
| | | | - Robert Stehle
- Vegetative Physiology, University of Cologne, Cologne, Germany
| | - Rasmus R Schröder
- Cryoelectron Microscopy, BioQuant, Medical Faculty, University of Heidelberg, Heidelberg, Germany
| | - Hans G Mannherz
- Department of Clinical Pharmacology and Molecular Cardiology, Ruhr-University of Bochum, Bochum, Germany.,Department of Anatomy and Embryology, Medical Faculty, Ruhr-University Bochum, Bochum, Germany
| | - Anna Kostareva
- Department of Molecular Biology and Genetics, Almazov Federal Medical Research Center, St. Petersburg, Russia.,Department of Women's and Children's Health and Center for Molecular Medicine, Karolinska Institute, Stockholm, Sweden
| | - Kornelia Jaquet
- Department of Clinical Pharmacology and Molecular Cardiology, Ruhr-University of Bochum, Bochum, Germany.,Cardiology, Bergmannsheil and St. Josef Hospital, Clinics of the Ruhr-University Bochum, Bochum, Germany
| |
Collapse
|
13
|
Nakano SJ, Walker JS, Walker LA, Li X, Du Y, Miyamoto SD, Sucharov CC, Garcia AM, Mitchell MB, Ambardekar AV, Stauffer BL. Increased myocyte calcium sensitivity in end-stage pediatric dilated cardiomyopathy. Am J Physiol Heart Circ Physiol 2019; 317:H1221-H1230. [PMID: 31625780 DOI: 10.1152/ajpheart.00409.2019] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Dilated cardiomyopathy (DCM) is the most common cause of heart failure (HF) in children, resulting in high mortality and need for heart transplantation. The pathophysiology underlying pediatric DCM is largely unclear; however, there is emerging evidence that molecular adaptations and response to conventional HF medications differ between children and adults. To gain insight into alterations leading to systolic dysfunction in pediatric DCM, we measured cardiomyocyte contractile properties and sarcomeric protein phosphorylation in explanted pediatric DCM myocardium (N = 8 subjects) compared with nonfailing (NF) pediatric hearts (N = 8 subjects). Force-pCa curves were generated from skinned cardiomyocytes in the presence and absence of protein kinase A. Sarcomeric protein phosphorylation was quantified with Pro-Q Diamond staining after gel electrophoresis. Pediatric DCM cardiomyocytes demonstrate increased calcium sensitivity (pCa50 =5.70 ± 0.0291), with an associated decrease in troponin (Tn)I phosphorylation compared with NF pediatric cardiomyocytes (pCa50 =5.59 ± 0.0271, P = 0.0073). Myosin binding protein C and TnT phosphorylation are also lower in pediatric DCM, whereas desmin phosphorylation is increased. Pediatric DCM cardiomyocytes generate peak tension comparable to that of NF pediatric cardiomyocytes [DCM 29.7 mN/mm2, interquartile range (IQR) 21.5-49.2 vs. NF 32.8 mN/mm2, IQR 21.5-49.2 mN/mm2; P = 0.6125]. In addition, cooperativity is decreased in pediatric DCM compared with pediatric NF (Hill coefficient: DCM 1.56, IQR 1.31-1.94 vs. NF 1.94, IQR 1.36-2.86; P = 0.0425). Alterations in sarcomeric phosphorylation and cardiomyocyte contractile properties may represent an impaired compensatory response, contributing to the detrimental DCM phenotype in children.NEW & NOTEWORTHY Our study is the first to demonstrate that cardiomyocytes from infants and young children with dilated cardiomyopathy (DCM) exhibit increased calcium sensitivity (likely mediated by decreased troponin I phosphorylation) compared with nonfailing pediatric cardiomyocytes. Compared with published values in adult cardiomyocytes, pediatric cardiomyocytes have notably decreased cooperativity, with a further reduction in the setting of DCM. Distinct adaptations in cardiomyocyte contractile properties may contribute to a differential response to pharmacological therapies in the pediatric DCM population.
Collapse
Affiliation(s)
- Stephanie J Nakano
- Division of Cardiology, Department of Pediatrics, University of Colorado Denver, Aurora, Colorado
| | - John S Walker
- Division of Cardiology, Department of Medicine, University of Colorado Denver, Aurora, Colorado
| | - Lori A Walker
- Division of Cardiology, Department of Medicine, University of Colorado Denver, Aurora, Colorado
| | - Xiaotao Li
- Division of Cardiology, Department of Medicine, University of Colorado Denver, Aurora, Colorado
| | - Yanmei Du
- Division of Cardiology, Department of Medicine, University of Colorado Denver, Aurora, Colorado
| | - Shelley D Miyamoto
- Division of Cardiology, Department of Pediatrics, University of Colorado Denver, Aurora, Colorado
| | - Carmen C Sucharov
- Division of Cardiology, Department of Medicine, University of Colorado Denver, Aurora, Colorado
| | - Anastacia M Garcia
- Division of Cardiology, Department of Pediatrics, University of Colorado Denver, Aurora, Colorado
| | - Max B Mitchell
- Division of Cardiothoracic Surgery, Department of Surgery, University of Colorado Denver, Aurora, Colorado
| | - Amrut V Ambardekar
- Division of Cardiology, Department of Medicine, University of Colorado Denver, Aurora, Colorado
| | - Brian L Stauffer
- Division of Cardiology, Department of Medicine, University of Colorado Denver, Aurora, Colorado.,Division of Cardiology, Department of Medicine, Denver Health and Hospital Authority, Denver, Colorado
| |
Collapse
|
14
|
Abstract
The cardiac troponin complex, composed of three regulatory proteins (cTnI, cTnT, TnC), functions as the critical regulator of cardiac muscle contraction and relaxation. Myofilament protein-protein interactions are regulated by post-translational modifications (PTMs) to the protein constituents of this complex. Dysregulation of troponin PTMs, particularly phosphorylation, results in altered cardiac contractility. Altered PTMs and isoforms have been increasingly recognized as the molecular mechanisms underlying heart diseases. Therefore, it is essential to comprehensively analyze cardiac troponin proteoforms that arise from PTMs, alternative splicing, and sequence variations. In this chapter, we described two detailed protocols for the enrichment and purification of endogenous cardiac troponin proteoforms from cardiac tissue. Subsequently, mass spectrometry (MS)-based top-down proteomics utilizing online liquid chromatography (LC)/quadrupole time-of-flight (Q-TOF) MS for separation, profiling, and quantification of the troponins was demonstrated. Characterization of troponin amino acid sequence and the localization of PTMs were shown using Fourier-transform ion cyclotron resonance (FT-ICR) MS with electron capture dissociation (ECD) and collisionally activated dissociation (CAD). Furthermore, we described the use of MASH software, a comprehensive and free software package developed in our lab, for top-down proteomics data analysis. The methods we described can be applied for the analysis of troponin proteoforms in cardiac tissues, from animal models to human clinical samples, for heart disease.
Collapse
|
15
|
van der Velden J, Stienen GJM. Cardiac Disorders and Pathophysiology of Sarcomeric Proteins. Physiol Rev 2019; 99:381-426. [PMID: 30379622 DOI: 10.1152/physrev.00040.2017] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The sarcomeric proteins represent the structural building blocks of heart muscle, which are essential for contraction and relaxation. During recent years, it has become evident that posttranslational modifications of sarcomeric proteins, in particular phosphorylation, tune cardiac pump function at rest and during exercise. This delicate, orchestrated interaction is also influenced by mutations, predominantly in sarcomeric proteins, which cause hypertrophic or dilated cardiomyopathy. In this review, we follow a bottom-up approach starting from a description of the basic components of cardiac muscle at the molecular level up to the various forms of cardiac disorders at the organ level. An overview is given of sarcomere changes in acquired and inherited forms of cardiac disease and the underlying disease mechanisms with particular reference to human tissue. A distinction will be made between the primary defect and maladaptive/adaptive secondary changes. Techniques used to unravel functional consequences of disease-induced protein changes are described, and an overview of current and future treatments targeted at sarcomeric proteins is given. The current evidence presented suggests that sarcomeres not only form the basis of cardiac muscle function but also represent a therapeutic target to combat cardiac disease.
Collapse
Affiliation(s)
- Jolanda van der Velden
- Amsterdam UMC, Vrije Universiteit Amsterdam, Physiology, Amsterdam Cardiovascular Sciences, Amsterdam , The Netherlands ; and Department of Physiology, Kilimanjaro Christian Medical University College, Moshi, Tanzania
| | - Ger J M Stienen
- Amsterdam UMC, Vrije Universiteit Amsterdam, Physiology, Amsterdam Cardiovascular Sciences, Amsterdam , The Netherlands ; and Department of Physiology, Kilimanjaro Christian Medical University College, Moshi, Tanzania
| |
Collapse
|
16
|
Biesiadecki BJ, Westfall MV. Troponin I modulation of cardiac performance: Plasticity in the survival switch. Arch Biochem Biophys 2019; 664:9-14. [PMID: 30684464 DOI: 10.1016/j.abb.2019.01.025] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Revised: 12/11/2018] [Accepted: 01/22/2019] [Indexed: 01/21/2023]
Abstract
Signaling complexes targeting the myofilament are essential in modulating cardiac performance. A central target of this signaling is cardiac troponin I (cTnI) phosphorylation. This review focuses on cTnI phosphorylation as a model for myofilament signaling, discussing key gaps and future directions towards understanding complex myofilament modulation of cardiac performance. Human heart cTnI is phosphorylated at 14 sites, giving rise to a complex modulatory network of varied functional responses. For example, while classical Ser23/24 phosphorylation mediates accelerated relaxation, protein kinase C phosphorylation of cTnI serves as a brake on contractile function. Additionally, the functional response of cTnI multi-site phosphorylation cannot necessarily be predicted from the response of individual sites alone. These complexities underscore the need for systematically evaluating single and multi-site phosphorylation on myofilament cellular and in vivo contractile function. Ultimately, a complete understanding of these multi-site responses requires work to establish site occupancy and dominance, kinase/phosphatase signaling balance, and the function of adaptive secondary phosphorylation. As cTnI phosphorylation is essential for modulating cardiac performance, future insight into the complex role of cTnI phosphorylation is important to establish sarcomere signaling in the healthy heart as well as identification of novel myofilament targets in the treatment of disease.
Collapse
Affiliation(s)
- Brandon J Biesiadecki
- Department of Physiology and Cell Biology, The Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH, 43210, USA.
| | - Margaret V Westfall
- Department of Cardiac Surgery, University of Michigan, Ann Arbor, MI, 48109, USA.
| |
Collapse
|
17
|
Vikhorev PG, Vikhoreva NN. Cardiomyopathies and Related Changes in Contractility of Human Heart Muscle. Int J Mol Sci 2018; 19:ijms19082234. [PMID: 30065175 PMCID: PMC6121228 DOI: 10.3390/ijms19082234] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2018] [Revised: 07/22/2018] [Accepted: 07/27/2018] [Indexed: 02/07/2023] Open
Abstract
About half of hypertrophic and dilated cardiomyopathies cases have been recognized as genetic diseases with mutations in sarcomeric proteins. The sarcomeric proteins are involved in cardiomyocyte contractility and its regulation, and play a structural role. Mutations in non-sarcomeric proteins may induce changes in cell signaling pathways that modify contractile response of heart muscle. These facts strongly suggest that contractile dysfunction plays a central role in initiation and progression of cardiomyopathies. In fact, abnormalities in contractile mechanics of myofibrils have been discovered. However, it has not been revealed how these mutations increase risk for cardiomyopathy and cause the disease. Much research has been done and still much is being done to understand how the mechanism works. Here, we review the facts of cardiac myofilament contractility in patients with cardiomyopathy and heart failure.
Collapse
Affiliation(s)
- Petr G Vikhorev
- National Heart and Lung Institute, Imperial College London, London W12 0NN, UK.
| | - Natalia N Vikhoreva
- Heart Science Centre, Magdi Yacoub Institute, Harefield Hospital, London UB9 6JH, UK.
| |
Collapse
|
18
|
Ryba DM, Li J, Cowan CL, Russell B, Wolska BM, Solaro RJ. Long-Term Biased β-Arrestin Signaling Improves Cardiac Structure and Function in Dilated Cardiomyopathy. Circulation 2017; 135:1056-1070. [PMID: 28104714 DOI: 10.1161/circulationaha.116.024482] [Citation(s) in RCA: 64] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/13/2016] [Accepted: 01/12/2017] [Indexed: 12/20/2022]
Abstract
BACKGROUND Biased agonism of the angiotensin II receptor is known to promote cardiac contractility. Our laboratory indicated that these effects may be attributable to changes at the level of the myofilaments. However, these signaling mechanisms remain unknown. Because a common finding in dilated cardiomyopathy is a reduction in the myofilament-Ca2+ response, we hypothesized that β-arrestin signaling would increase myofilament-Ca2+ responsiveness in a model of familial dilated cardiomyopathy and improve cardiac function and morphology. METHODS We treated a dilated cardiomyopathy-linked mouse model expressing a mutant tropomyosin (Tm-E54K) for 3 months with either TRV120067, a β-arrestin 2-biased ligand of the angiotensin II receptor, or losartan, an angiotensin II receptor blocker. At the end of the treatment protocol, we assessed cardiac function using echocardiography, the myofilament-Ca2+ response of detergent-extracted fiber bundles, and used proteomic approaches to understand changes in posttranslational modifications of proteins that may explain functional changes. We also assessed signaling pathways altered in vivo and by using isolated myocytes. RESULTS TRV120067- treated Tm-E54K mice showed improved cardiac structure and function, whereas losartan-treated mice had no improvement. Myofilaments of TRV120067-treated Tm-E54K mice had significantly improved myofilament-Ca2+ responsiveness, which was depressed in untreated Tm-E54K mice. We attributed these changes to increased MLC2v and MYPT1/2 phosphorylation seen only in TRV120067-treated mice. We found that the functional changes were attributable to an activation of ERK1/2-RSK3 signaling, mediated through β-arrestin, which may have a novel role in increasing MLC2v phosphorylation through a previously unrecognized interaction of β-arrestin localized to the sarcomere. CONCLUSIONS Long-term β-arrestin 2-biased agonism of the angiotensin II receptor may be a viable approach to the treatment of dilated cardiomyopathy by not only preventing maladaptive signaling, but also improving cardiac function by altering the myofilament-Ca2+ response via β-arrestin signaling pathways.
Collapse
Affiliation(s)
- David M Ryba
- From Department of Physiology and Biophysics and Center for Cardiovascular Research, University of Illinois at Chicago (D.M.R., J.L., B.R., B.M.W., R.J.S.); Department of Medicine, Division of Cardiology, University of Illinois at Chicago (B.M.W.); and Trevena, Inc. King of Prussia, PA (B.M.W.)
| | - Jieli Li
- From Department of Physiology and Biophysics and Center for Cardiovascular Research, University of Illinois at Chicago (D.M.R., J.L., B.R., B.M.W., R.J.S.); Department of Medicine, Division of Cardiology, University of Illinois at Chicago (B.M.W.); and Trevena, Inc. King of Prussia, PA (B.M.W.)
| | - Conrad L Cowan
- From Department of Physiology and Biophysics and Center for Cardiovascular Research, University of Illinois at Chicago (D.M.R., J.L., B.R., B.M.W., R.J.S.); Department of Medicine, Division of Cardiology, University of Illinois at Chicago (B.M.W.); and Trevena, Inc. King of Prussia, PA (B.M.W.)
| | - Brenda Russell
- From Department of Physiology and Biophysics and Center for Cardiovascular Research, University of Illinois at Chicago (D.M.R., J.L., B.R., B.M.W., R.J.S.); Department of Medicine, Division of Cardiology, University of Illinois at Chicago (B.M.W.); and Trevena, Inc. King of Prussia, PA (B.M.W.)
| | - Beata M Wolska
- From Department of Physiology and Biophysics and Center for Cardiovascular Research, University of Illinois at Chicago (D.M.R., J.L., B.R., B.M.W., R.J.S.); Department of Medicine, Division of Cardiology, University of Illinois at Chicago (B.M.W.); and Trevena, Inc. King of Prussia, PA (B.M.W.)
| | - R John Solaro
- From Department of Physiology and Biophysics and Center for Cardiovascular Research, University of Illinois at Chicago (D.M.R., J.L., B.R., B.M.W., R.J.S.); Department of Medicine, Division of Cardiology, University of Illinois at Chicago (B.M.W.); and Trevena, Inc. King of Prussia, PA (B.M.W.).
| |
Collapse
|
19
|
Salhi HE, Hassel NC, Siddiqui JK, Brundage EA, Ziolo MT, Janssen PML, Davis JP, Biesiadecki BJ. Myofilament Calcium Sensitivity: Mechanistic Insight into TnI Ser-23/24 and Ser-150 Phosphorylation Integration. Front Physiol 2016; 7:567. [PMID: 28018230 PMCID: PMC5156683 DOI: 10.3389/fphys.2016.00567] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2016] [Accepted: 11/08/2016] [Indexed: 11/14/2022] Open
Abstract
Troponin I (TnI) is a major regulator of cardiac muscle contraction and relaxation. During physiological and pathological stress, TnI is differentially phosphorylated at multiple residues through different signaling pathways to match cardiac function to demand. The combination of these TnI phosphorylations can exhibit an expected or unexpected functional integration, whereby the function of two phosphorylations are different than that predicted from the combined function of each individual phosphorylation alone. We have shown that TnI Ser-23/24 and Ser-150 phosphorylation exhibit functional integration and are simultaneously increased in response to cardiac stress. In the current study, we investigated the functional integration of TnI Ser-23/24 and Ser-150 to alter cardiac contraction. We hypothesized that Ser-23/24 and Ser-150 phosphorylation each utilize distinct molecular mechanisms to alter the TnI binding affinity within the thin filament. Mathematical modeling predicts that Ser-23/24 and Ser-150 phosphorylation affect different TnI affinities within the thin filament to distinctly alter the Ca2+-binding properties of troponin. Protein binding experiments validate this assertion by demonstrating pseudo-phosphorylated Ser-150 decreases the affinity of isolated TnI for actin, whereas Ser-23/24 pseudo-phosphorylation is not different from unphosphorylated. Thus, our data supports that TnI Ser-23/24 affects TnI-TnC binding, while Ser-150 phosphorylation alters TnI-actin binding. By measuring force development in troponin-exchanged skinned myocytes, we demonstrate that the Ca2+ sensitivity of force is directly related to the amount of phosphate present on TnI. Furthermore, we demonstrate that Ser-150 pseudo-phosphorylation blunts Ser-23/24-mediated decreased Ca2+-sensitive force development whether on the same or different TnI molecule. Therefore, TnI phosphorylations can integrate across troponins along the myofilament. These data demonstrate that TnI Ser-23/24 and Ser-150 phosphorylation regulates muscle contraction in part by modulating different TnI interactions in the thin filament and it is the combination of these differential mechanisms that provides understanding of their functional integration.
Collapse
Affiliation(s)
- Hussam E Salhi
- Department of Physiology and Cell Biology and Davis Heart and Lung Research Institute, Ohio State University Columbus, OH, USA
| | - Nathan C Hassel
- Department of Physiology and Cell Biology and Davis Heart and Lung Research Institute, Ohio State University Columbus, OH, USA
| | - Jalal K Siddiqui
- Department of Physiology and Cell Biology and Davis Heart and Lung Research Institute, Ohio State University Columbus, OH, USA
| | - Elizabeth A Brundage
- Department of Physiology and Cell Biology and Davis Heart and Lung Research Institute, Ohio State University Columbus, OH, USA
| | - Mark T Ziolo
- Department of Physiology and Cell Biology and Davis Heart and Lung Research Institute, Ohio State University Columbus, OH, USA
| | - Paul M L Janssen
- Department of Physiology and Cell Biology and Davis Heart and Lung Research Institute, Ohio State University Columbus, OH, USA
| | - Jonathan P Davis
- Department of Physiology and Cell Biology and Davis Heart and Lung Research Institute, Ohio State University Columbus, OH, USA
| | - Brandon J Biesiadecki
- Department of Physiology and Cell Biology and Davis Heart and Lung Research Institute, Ohio State University Columbus, OH, USA
| |
Collapse
|
20
|
Gresham KS, Stelzer JE. The contributions of cardiac myosin binding protein C and troponin I phosphorylation to β-adrenergic enhancement of in vivo cardiac function. J Physiol 2016; 594:669-86. [PMID: 26635197 DOI: 10.1113/jp270959] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2015] [Accepted: 11/30/2015] [Indexed: 01/12/2023] Open
Abstract
KEY POINTS β-adrenergic stimulation increases cardiac myosin binding protein C (MyBP-C) and troponin I phosphorylation to accelerate pressure development and relaxation in vivo, although their relative contributions remain unknown. Using a novel mouse model lacking protein kinase A-phosphorylatable troponin I (TnI) and MyBP-C, we examined in vivo haemodynamic function before and after infusion of the β-agonist dobutamine. Mice expressing phospho-ablated MyBP-C displayed cardiac hypertrophy and prevented full acceleration of pressure development and relaxation in response to dobutamine, whereas expression of phosphor-ablated TnI alone had little effect on the acceleration of contractile function in response to dobutamine. Our data demonstrate that MyBP-C phosphorylation is the principal mediator of the contractile response to increased β-agonist stimulation in vivo. These results help us understand why MyBP-C dephosphorylation in the failing heart contributes to contractile dysfunction and decreased adrenergic reserve in response to acute stress. β-adrenergic stimulation plays a critical role in accelerating ventricular contraction and speeding relaxation to match cardiac output to changing circulatory demands. Two key myofilaments proteins, troponin I (TnI) and myosin binding protein-C (MyBP-C), are phosphorylated following β-adrenergic stimulation; however, their relative contributions to the enhancement of in vivo cardiac contractility are unknown. To examine the roles of TnI and MyBP-C phosphorylation in β-adrenergic-mediated enhancement of cardiac function, transgenic (TG) mice expressing non-phosphorylatable TnI protein kinase A (PKA) residues (i.e. serine to alanine substitution at Ser23/24; TnI(PKA-)) were bred with mice expressing non-phosphorylatable MyBP-C PKA residues (i.e. serine to alanine substitution at Ser273, Ser282 and Ser302; MyBPC(PKA-)) to generate a novel mouse model expressing non-phosphorylatable PKA residues in TnI and MyBP-C (DBL(PKA-)). MyBP-C dephosphorylation produced cardiac hypertrophy and increased wall thickness in MyBPC(PKA-) and DBL(PKA-) mice, and in vivo echocardiography and pressure-volume catheterization studies revealed impaired systolic function and prolonged diastolic relaxation compared to wild-type and TnI(PKA-) mice. Infusion of the β-agonist dobutamine resulted in accelerated rates of pressure development and relaxation in all mice; however, MyBPC(PKA-) and DBL(PKA-) mice displayed a blunted contractile response compared to wild-type and TnI(PKA-) mice. Furthermore, unanaesthesized MyBPC(PKA-) and DBL(PKA-) mice displayed depressed maximum systolic pressure in response to dobutamine as measured using implantable telemetry devices. Taken together, our data show that MyBP-C phosphorylation is a critical modulator of the in vivo acceleration of pressure development and relaxation as a result of enhanced β-adrenergic stimulation, and reduced MyBP-C phosphorylation may underlie depressed adrenergic reserve in heart failure.
Collapse
Affiliation(s)
- Kenneth S Gresham
- 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
| |
Collapse
|
21
|
Lorenzen-Schmidt I, Clarke SB, Pyle WG. The neglected messengers: Control of cardiac myofilaments by protein phosphatases. J Mol Cell Cardiol 2016; 101:81-89. [PMID: 27721025 DOI: 10.1016/j.yjmcc.2016.10.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Revised: 10/03/2016] [Accepted: 10/05/2016] [Indexed: 01/21/2023]
Abstract
Cardiac myofilaments act as the central contractile apparatus of heart muscle cells. Covalent modification of constituent proteins through phosphorylation is a rapid and powerful mechanism to control myofilament function, and is increasingly seen as a mechanism of disease. While the relationship between protein kinases and cardiac myofilaments has been widely examined, the impact of protein dephosphorylation by protein phosphatases is poorly understood. This review outlines the mechanisms by which the mostly widely expressed protein phosphatases in cardiac myocytes regulate myofilament function, and the emerging role of myofilament-associated protein phosphatases in heart failure. The importance of regulatory subunits and subcellular compartmentalization in determining the functional impact of protein phosphatases on myofilament and myocardial function is also discussed, as are discrepancies about the roles of protein phosphatases in regulating myofilament function. The potential for targeting these molecular messengers in the treatment of heart failure is discussed as a key future direction.
Collapse
Affiliation(s)
- Ilka Lorenzen-Schmidt
- Centre for Cardiovascular Investigations, Department of Biomedical Sciences, Ontario Veterinary College, University of Guelph, Guelph, ON N1G 2W1, Canada
| | - Samantha B Clarke
- Centre for Cardiovascular Investigations, Department of Biomedical Sciences, Ontario Veterinary College, University of Guelph, Guelph, ON N1G 2W1, Canada
| | - W Glen Pyle
- Centre for Cardiovascular Investigations, Department of Biomedical Sciences, Ontario Veterinary College, University of Guelph, Guelph, ON N1G 2W1, Canada.
| |
Collapse
|
22
|
Westfall MV. Contribution of Post-translational Phosphorylation to Sarcomere-Linked Cardiomyopathy Phenotypes. Front Physiol 2016; 7:407. [PMID: 27683560 PMCID: PMC5021686 DOI: 10.3389/fphys.2016.00407] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2016] [Accepted: 08/30/2016] [Indexed: 01/24/2023] Open
Abstract
Secondary shifts develop in post-translational phosphorylation of sarcomeric proteins in multiple animal models of inherited cardiomyopathy. These signaling alterations together with the primary mutation are predicted to contribute to the overall cardiac phenotype. As a result, identification and integration of post-translational myofilament signaling responses are identified as priorities for gaining insights into sarcomeric cardiomyopathies. However, significant questions remain about the nature and contribution of post-translational phosphorylation to structural remodeling and cardiac dysfunction in animal models and human patients. This perspective essay discusses specific goals for filling critical gaps about post-translational signaling in response to these inherited mutations, especially within sarcomeric proteins. The discussion focuses primarily on pre-clinical analysis of animal models and defines challenges and future directions in this field.
Collapse
|
23
|
Birch CL, Behunin SM, Lopez-Pier MA, Danilo C, Lipovka Y, Saripalli C, Granzier H, Konhilas JP. Sex dimorphisms of crossbridge cycling kinetics in transgenic hypertrophic cardiomyopathy mice. Am J Physiol Heart Circ Physiol 2016; 311:H125-36. [PMID: 27199124 DOI: 10.1152/ajpheart.00592.2015] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/27/2015] [Accepted: 05/03/2016] [Indexed: 11/22/2022]
Abstract
Familial hypertrophic cardiomyopathy (HCM) is a disease of the sarcomere and may lead to hypertrophic, dilated, restrictive, and/or arrhythmogenic cardiomyopathy, congestive heart failure, or sudden cardiac death. We hypothesized that hearts from transgenic HCM mice harboring a mutant myosin heavy chain increase the energetic cost of contraction in a sex-specific manner. To do this, we assessed Ca(2+) sensitivity of tension and crossbridge kinetics in demembranated cardiac trabeculas from male and female wild-type (WT) and HCM hearts at an early time point (2 mo of age). We found a significant effect of sex on Ca(2+) sensitivity such that male, but not female, HCM mice displayed a decrease in Ca(2+) sensitivity compared with WT counterparts. The HCM transgene and sex significantly impacted the rate of force redevelopment by a rapid release-restretch protocol and tension cost by the ATPase-tension relationship. In each of these measures, HCM male trabeculas displayed a gain-of-function when compared with WT counterparts. In addition, cardiac remodeling measured by echocardiography, histology, morphometry, and posttranslational modifications demonstrated sex- and HCM-specific effects. In conclusion, female and male HCM mice display sex dimorphic crossbridge kinetics accompanied by sex- and HCM-dependent cardiac remodeling at the morphometric, histological, and cellular level.
Collapse
Affiliation(s)
- Camille L Birch
- Sarver Molecular Cardiovascular Research Program, University of Arizona, Tucson, Arizona; Department of Biomedical Engineering, University of Arizona, Tucson, Arizona
| | - Samantha M Behunin
- Department of Physiology, University of Arizona, Tucson, Arizona; Sarver Molecular Cardiovascular Research Program, University of Arizona, Tucson, Arizona
| | - Marissa A Lopez-Pier
- Sarver Molecular Cardiovascular Research Program, University of Arizona, Tucson, Arizona; Department of Biomedical Engineering, University of Arizona, Tucson, Arizona
| | - Christiane Danilo
- Department of Physiology, University of Arizona, Tucson, Arizona; Sarver Molecular Cardiovascular Research Program, University of Arizona, Tucson, Arizona
| | - Yulia Lipovka
- Sarver Molecular Cardiovascular Research Program, University of Arizona, Tucson, Arizona; Department of Molecular and Cellular Biology, University of Arizona, Tucson, Arizona; and
| | - Chandra Saripalli
- Sarver Molecular Cardiovascular Research Program, University of Arizona, Tucson, Arizona; Department of Cellular and Molecular Medicine, University of Arizona, Tucson, Arizona
| | - Henk Granzier
- Sarver Molecular Cardiovascular Research Program, University of Arizona, Tucson, Arizona; Department of Cellular and Molecular Medicine, University of Arizona, Tucson, Arizona
| | - John P Konhilas
- Department of Physiology, University of Arizona, Tucson, Arizona; Sarver Molecular Cardiovascular Research Program, University of Arizona, Tucson, Arizona;
| |
Collapse
|
24
|
Ramirez-Correa GA, Ma J, Slawson C, Zeidan Q, Lugo-Fagundo NS, Xu M, Shen X, Gao WD, Caceres V, Chakir K, DeVine L, Cole RN, Marchionni L, Paolocci N, Hart GW, Murphy AM. Removal of Abnormal Myofilament O-GlcNAcylation Restores Ca2+ Sensitivity in Diabetic Cardiac Muscle. Diabetes 2015; 64:3573-87. [PMID: 26109417 PMCID: PMC4587639 DOI: 10.2337/db14-1107] [Citation(s) in RCA: 69] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/01/2014] [Accepted: 05/14/2015] [Indexed: 11/13/2022]
Abstract
Contractile dysfunction and increased deposition of O-linked β-N-acetyl-d-glucosamine (O-GlcNAc) in cardiac proteins are a hallmark of the diabetic heart. However, whether and how this posttranslational alteration contributes to lower cardiac function remains unclear. Using a refined β-elimination/Michael addition with tandem mass tags (TMT)-labeling proteomic technique, we show that CpOGA, a bacterial analog of O-GlcNAcase (OGA) that cleaves O-GlcNAc in vivo, removes site-specific O-GlcNAcylation from myofilaments, restoring Ca(2+) sensitivity in streptozotocin (STZ) diabetic cardiac muscles. We report that in control rat hearts, O-GlcNAc and O-GlcNAc transferase (OGT) are mainly localized at the Z-line, whereas OGA is at the A-band. Conversely, in diabetic hearts O-GlcNAc levels are increased and OGT and OGA delocalized. Consistent changes were found in human diabetic hearts. STZ diabetic hearts display increased physical interactions of OGA with α-actin, tropomyosin, and myosin light chain 1, along with reduced OGT and increased OGA activities. Our study is the first to reveal that specific removal of O-GlcNAcylation restores myofilament response to Ca(2+) in diabetic hearts and that altered O-GlcNAcylation is due to the subcellular redistribution of OGT and OGA rather than to changes in their overall activities. Thus, preventing sarcomeric OGT and OGA displacement represents a new possible strategy for treating diabetic cardiomyopathy.
Collapse
Affiliation(s)
- Genaro A Ramirez-Correa
- Division of Cardiology, Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Junfeng Ma
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Chad Slawson
- Department of Biochemistry and Molecular Biology, University of Kansas Medical Center, Kansas City, KS
| | - Quira Zeidan
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Nahyr S Lugo-Fagundo
- Division of Cardiology, Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Mingguo Xu
- Division of Cardiology, Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Xiaoxu Shen
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Wei Dong Gao
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Viviane Caceres
- Division of Cardiology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Khalid Chakir
- Division of Cardiology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Lauren DeVine
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Robert N Cole
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Luigi Marchionni
- Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Nazareno Paolocci
- Division of Cardiology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Gerald W Hart
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Anne M Murphy
- Division of Cardiology, Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, MD
| |
Collapse
|
25
|
Vikhorev PG, Song W, Wilkinson R, Copeland O, Messer AE, Ferenczi MA, Marston SB. The dilated cardiomyopathy-causing mutation ACTC E361G in cardiac muscle myofibrils specifically abolishes modulation of Ca(2+) regulation by phosphorylation of troponin I. Biophys J 2015; 107:2369-80. [PMID: 25418306 PMCID: PMC4241448 DOI: 10.1016/j.bpj.2014.10.024] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2014] [Revised: 09/25/2014] [Accepted: 10/16/2014] [Indexed: 01/30/2023] Open
Abstract
Phosphorylation of troponin I by protein kinase A (PKA) reduces Ca2+ sensitivity and increases the rate of Ca2+ release from troponin C and the rate of relaxation in cardiac muscle. In vitro experiments indicate that mutations that cause dilated cardiomyopathy (DCM) uncouple this modulation, but this has not been demonstrated in an intact contractile system. Using a Ca2+-jump protocol, we measured the effect of the DCM-causing mutation ACTC E361G on the equilibrium and kinetic parameters of Ca2+ regulation of contractility in single transgenic mouse heart myofibrils. We used propranolol treatment of mice to reduce the level of troponin I and myosin binding protein C (MyBP-C) phosphorylation in their hearts before isolating the myofibrils. In nontransgenic mouse myofibrils, the Ca2+ sensitivity of force was increased, the fast relaxation phase rate constant, kREL, was reduced, and the length of the slow linear phase, tLIN, was increased when the troponin I phosphorylation level was reduced from 1.02 to 0.3 molPi/TnI (EC50 P/unP = 1.8 ± 0.2, p < 0.001). Native myofibrils from ACTC E361G transgenic mice had a 2.4-fold higher Ca2+ sensitivity than nontransgenic mouse myofibrils. Strikingly, the Ca2+ sensitivity and relaxation parameters of ACTC E361G myofibrils did not depend on the troponin I phosphorylation level (EC50 P/unP = 0.88 ± 0.17, p = 0.39). Nevertheless, modulation of the Ca2+ sensitivity of ACTC E361G myofibrils by sarcomere length or EMD57033 was indistinguishable from that of nontransgenic myofibrils. Overall, EC50 measured in different conditions varied over a 7-fold range. The time course of relaxation, as defined by tLIN and kREL, was correlated with EC50 but varied by just 2.7- and 3.3-fold, respectively. Our results confirm that troponin I phosphorylation specifically alters the Ca2+ sensitivity of isometric tension and the time course of relaxation in cardiac muscle myofibrils. Moreover, the DCM-causing mutation ACTC E361G blunts this phosphorylation-dependent response without affecting other parameters of contraction, including length-dependent activation and the response to EMD57033.
Collapse
Affiliation(s)
- Petr G Vikhorev
- National Heart and Lung Institute, Imperial College London, London, UK
| | - Weihua Song
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore
| | - Ross Wilkinson
- National Heart and Lung Institute, Imperial College London, London, UK
| | - O'Neal Copeland
- National Heart and Lung Institute, Imperial College London, London, UK
| | - Andrew E Messer
- National Heart and Lung Institute, Imperial College London, London, UK
| | - Michael A Ferenczi
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore
| | - Steven B Marston
- National Heart and Lung Institute, Imperial College London, London, UK.
| |
Collapse
|
26
|
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.
Collapse
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.
| |
Collapse
|
27
|
Wijnker PJM, Li Y, Zhang P, Foster DB, dos Remedios C, Van Eyk JE, Stienen GJM, Murphy AM, van der Velden J. A novel phosphorylation site, Serine 199, in the C-terminus of cardiac troponin I regulates calcium sensitivity and susceptibility to calpain-induced proteolysis. J Mol Cell Cardiol 2015; 82:93-103. [PMID: 25771144 DOI: 10.1016/j.yjmcc.2015.03.006] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/26/2014] [Revised: 03/04/2015] [Accepted: 03/05/2015] [Indexed: 12/28/2022]
Abstract
Phosphorylation of cardiac troponin I (cTnI) by protein kinase C (PKC) is implicated in cardiac dysfunction. Recently, Serine 199 (Ser199) was identified as a target for PKC phosphorylation and increased Ser199 phosphorylation occurs in end-stage failing compared with non-failing human myocardium. The functional consequences of cTnI-Ser199 phosphorylation in the heart are unknown. Therefore, we investigated the impact of phosphorylation of cTnI-Ser199 on myofilament function in human cardiac tissue and the susceptibility of cTnI to proteolysis. cTnI-Ser199 was replaced by aspartic acid (199D) or alanine (199A) to mimic phosphorylation and dephosphorylation, respectively, with recombinant wild-type (Wt) cTn as a negative control. Force development was measured at various [Ca(2+)] and at sarcomere lengths of 1.8 and 2.2 μm in demembranated cardiomyocytes in which endogenous cTn complex was exchanged with the recombinant human cTn complexes. In idiopathic dilated cardiomyopathy samples, myofilament Ca(2+)-sensitivity (pCa50) at 2.2 μm was significantly higher in 199D (pCa50 = 5.79 ± 0.01) compared to 199A (pCa50 = 5.65 ± 0.01) and Wt (pCa50 = 5.66 ± 0.02) at ~63% cTn exchange. Myofilament Ca(2+)-sensitivity was significantly higher even with only 5.9 ± 2.5% 199D exchange compared to 199A, and saturated at 12.3 ± 2.6% 199D exchange. Ser199 pseudo-phosphorylation decreased cTnI binding to both actin and actin-tropomyosin. Moreover, altered susceptibility of cTnI to proteolysis by calpain I was found when Ser199 was pseudo-phosphorylated. Our data demonstrate that low levels of cTnI-Ser199 pseudo-phosphorylation (~6%) increase myofilament Ca(2+)-sensitivity in human cardiomyocytes, most likely by decreasing the binding affinity of cTnI for actin-tropomyosin. In addition, cTnI-Ser199 pseudo-phosphorylation or mutation regulates calpain I mediated proteolysis of cTnI.
Collapse
Affiliation(s)
- Paul J M Wijnker
- Department of Physiology, Institute for Cardiovascular Research, VU University Medical Center, Amsterdam, The Netherlands; Department of Experimental Pharmacology and Toxicology, Cardiovascular Research Center, University Medical Center Hamburg-Eppendorf, Hamburg, Germany; Department of Physiology, Institute for Cardiovascular Research, VU University Medical Center, Amsterdam, The Netherlands.
| | - Yuejin Li
- Department of Pediatrics, Division of Cardiology, Johns Hopkins University School of Medicine, Baltimore, USA
| | - Pingbo Zhang
- Department of Pediatrics, Division of Cardiology, Johns Hopkins University School of Medicine, Baltimore, USA
| | - D Brian Foster
- Department of Pediatrics, Division of Cardiology, Johns Hopkins University School of Medicine, Baltimore, USA
| | - Cris dos Remedios
- Muscle Research Unit, Bosch Institute, The University of Sydney, Sydney, Australia
| | - Jennifer E Van Eyk
- The Advanced Clinical Biosystems Research Institute, The Heart Institute, Department of Medicine, Cedars Sinai Medical Center, Los Angeles, CA, USA
| | - Ger J M Stienen
- Department of Physiology, Institute for Cardiovascular Research, VU University Medical Center, Amsterdam, The Netherlands; Department of Physics and Astronomy, VU University, Amsterdam, The Netherlands
| | - Anne M Murphy
- Department of Pediatrics, Division of Cardiology, Johns Hopkins University School of Medicine, Baltimore, USA
| | - Jolanda van der Velden
- Department of Physiology, Institute for Cardiovascular Research, VU University Medical Center, Amsterdam, The Netherlands; ICIN-Netherlands Heart Institute, Utrecht, The Netherlands
| |
Collapse
|
28
|
Papp Z, van der Velden J, Borbély A, Édes I, Stienen GJM. Altered myocardial force generation in end-stage human heart failure. ESC Heart Fail 2015; 1:160-165. [PMID: 28834631 DOI: 10.1002/ehf2.12020] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2014] [Revised: 11/07/2014] [Accepted: 11/17/2014] [Indexed: 11/06/2022] Open
Abstract
AIMS This study aimed to elucidate the molecular background of increased Ca2+ sensitivity of force production in cardiomyocytes of end-stage human heart failure. METHODS AND RESULTS Ca2+ -activated isometric force and the cross-bridge specific rate of force redevelopment (ktr ) were determined in Triton-skinned myocytes from end-stage failing and non-failing donor hearts. Measurements (control: pH 7.2, 0 mM inorganic phosphate (Pi )) were performed under test conditions that probed either the Ca2+ -regulatory function of the thin filaments (pH 6.5), the kinetics of the actin-myosin cross-bridge cycle (10 mM Pi ), or both (pH 6.5, 10 mM Pi ). The control maximal Ca2+ -activated force (Fo ) and ktrmax did not differ between failing and non-failing myocytes. At submaximal [Ca2+ ], however, both force and ktr were higher in failing than in donor myocytes. The difference in the Ca2+ sensitivities of force production was preserved when the thin filament regulatory function was perturbed by acidosis (pH 6.5) but was abolished by cross-bridge modulation (i.e. by Pi ) both at pH 7.2 and at pH 6.5. Pi induced a larger reduction in force but a smaller increase in ktr in the failing myocytes than in the non-failing myocytes at submaximal [Ca2+ ]. CONCLUSION The enhanced Pi sensitivity of the actin-myosin interaction suggests that the Pi release step of the actin-myosin cross-bridge cycle is modified during end-stage human heart failure. This might be of functional importance when Pi accumulates (e.g. during cardiac ischaemia). Moreover, this alteration can influence cardiac energetics and the clinical efficacy of sarcomere targeted agents in human heart failure.
Collapse
Affiliation(s)
- Zoltán Papp
- Division of Clinical Physiology, Institute of Cardiology, University of Debrecen, 4032, Debrecen, Hungary
| | - Jolanda van der Velden
- Laboratory for Physiology, Institute of Cardiovascular Research (ICaR-VU), VU University Medical Center, Amsterdam, Netherlands
| | - Attila Borbély
- Division of Clinical Physiology, Institute of Cardiology, University of Debrecen, 4032, Debrecen, Hungary
| | - István Édes
- Division of Clinical Physiology, Institute of Cardiology, University of Debrecen, 4032, Debrecen, Hungary
| | - Ger J M Stienen
- Laboratory for Physiology, Institute of Cardiovascular Research (ICaR-VU), VU University Medical Center, Amsterdam, Netherlands
| |
Collapse
|
29
|
Biesiadecki BJ, Davis JP, Ziolo MT, Janssen PML. Tri-modal regulation of cardiac muscle relaxation; intracellular calcium decline, thin filament deactivation, and cross-bridge cycling kinetics. Biophys Rev 2014; 6:273-289. [PMID: 28510030 PMCID: PMC4255972 DOI: 10.1007/s12551-014-0143-5] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2014] [Accepted: 06/27/2014] [Indexed: 01/09/2023] Open
Abstract
Cardiac muscle relaxation is an essential step in the cardiac cycle. Even when the contraction of the heart is normal and forceful, a relaxation phase that is too slow will limit proper filling of the ventricles. Relaxation is too often thought of as a mere passive process that follows contraction. However, many decades of advancements in our understanding of cardiac muscle relaxation have shown it is a highly complex and well-regulated process. In this review, we will discuss three distinct events that can limit the rate of cardiac muscle relaxation: the rate of intracellular calcium decline, the rate of thin-filament de-activation, and the rate of cross-bridge cycling. Each of these processes are directly impacted by a plethora of molecular events. In addition, these three processes interact with each other, further complicating our understanding of relaxation. Each of these processes is continuously modulated by the need to couple bodily oxygen demand to cardiac output by the major cardiac physiological regulators. Length-dependent activation, frequency-dependent activation, and beta-adrenergic regulation all directly and indirectly modulate calcium decline, thin-filament deactivation, and cross-bridge kinetics. We hope to convey our conclusion that cardiac muscle relaxation is a process of intricate checks and balances, and should not be thought of as a single rate-limiting step that is regulated at a single protein level. Cardiac muscle relaxation is a system level property that requires fundamental integration of three governing systems: intracellular calcium decline, thin filament deactivation, and cross-bridge cycling kinetics.
Collapse
Affiliation(s)
- Brandon J Biesiadecki
- Department of Physiology and Cell Biology and Dorothy M. Davis Heart Lung Institute, College of Medicine, The Ohio State University, 304 Hamilton Hall, 1645 Neil Avenue, Columbus, OH, 43210-1218, USA
| | - Jonathan P Davis
- Department of Physiology and Cell Biology and Dorothy M. Davis Heart Lung Institute, College of Medicine, The Ohio State University, 304 Hamilton Hall, 1645 Neil Avenue, Columbus, OH, 43210-1218, USA
| | - Mark T Ziolo
- Department of Physiology and Cell Biology and Dorothy M. Davis Heart Lung Institute, College of Medicine, The Ohio State University, 304 Hamilton Hall, 1645 Neil Avenue, Columbus, OH, 43210-1218, USA
| | - Paul M L Janssen
- Department of Physiology and Cell Biology and Dorothy M. Davis Heart Lung Institute, College of Medicine, The Ohio State University, 304 Hamilton Hall, 1645 Neil Avenue, Columbus, OH, 43210-1218, USA.
| |
Collapse
|
30
|
Negative inotropic effects of epinephrine in the presence of increased β-adrenoceptor sensitivity during hypothermia in a rat model. Cryobiology 2014; 70:9-16. [PMID: 25445571 DOI: 10.1016/j.cryobiol.2014.10.012] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2014] [Revised: 10/21/2014] [Accepted: 10/29/2014] [Indexed: 11/22/2022]
Abstract
BACKGROUND Animal studies show reduced inotropic effects of cardiac β-adrenoceptor agonists like epinephrine (Epi) during hypothermia and rewarming, while drugs targeting other pharmacological mechanisms have positive effects. This study therefore aimed to determine β-adrenoceptor sensitivity in isolated cardiomyocytes and investigate hemodynamic effects of Epi and its ability to stimulate cardiac β-adrenoceptors at different temperatures in vivo. METHODS Isolated rat myocardial cells were incubated with the radioactive β-adrenoceptor ligand [(3)H]-CGP12177 and propranolol, used as a displacer. Cells were subjected to normothermia (37 °C) or hypothermia (15 °C). After incubation, radioactivity was measured to estimate β-adrenoceptor affinity for propranolol (IC50), as a measure of β-adrenoceptor sensitivity. In separate in vivo experiments, Epi (1.25 μg/min) was administered the last 5min of experiments in normothermic (37 °C, 5h), hypothermic (4h at 15 °C) and rewarmed rats (4h at 15 °C, and subsequently rewarmed to 37 °C). Hemodynamic parameters were monitored during infusion. Hearts were thereafter freeze-clamped and tissue cAMP was measured. RESULTS In vitro measurements of IC50 for propranolol showed a hypothermia-induced increase in β-adrenoceptor sensitivity at 15 °C. Corresponding in vivo experiments at 15 °C showed decreased cardiac output and stroke volume, whereas total peripheral resistance (TPR) increased during Epi infusion, simultaneous with a 4-fold cAMP increase. CONCLUSIONS This experiment shows a hypothermia-induced in vivo and in vitro increase of cardiac β-adrenoceptor sensitivity, and simultaneous lack of inotropic effects of Epi in the presence of increased TPR. Our findings therefore indicate that hypothermia-induced reduction in inotropic effects of Epi is due to substantial elevation of TPR, rather than β-adrenoceptor dysfunction.
Collapse
|
31
|
Salhi HE, Walton SD, Hassel NC, Brundage EA, de Tombe PP, Janssen PML, Davis JP, Biesiadecki BJ. Cardiac troponin I tyrosine 26 phosphorylation decreases myofilament Ca2+ sensitivity and accelerates deactivation. J Mol Cell Cardiol 2014; 76:257-64. [PMID: 25252176 DOI: 10.1016/j.yjmcc.2014.09.013] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/07/2014] [Revised: 09/09/2014] [Accepted: 09/12/2014] [Indexed: 10/24/2022]
Abstract
Troponin I (TnI), the inhibitory subunit of the troponin complex, can be phosphorylated as a key regulatory mechanism to alter the calcium regulation of contraction. Recent work has identified phosphorylation of TnI Tyr-26 in the human heart with unknown functional effects. We hypothesized that TnI Tyr-26N-terminal phosphorylation decreases calcium sensitivity of the thin filament, similar to the desensitizing effects of TnI Ser-23/24 phosphorylation. Our results demonstrate that Tyr-26 phosphorylation and pseudo-phosphorylation decrease calcium binding to troponin C (TnC) on the thin filament and calcium sensitivity of force development to a similar magnitude as TnI Ser-23/24 pseudo-phosphorylation. To investigate the effects of TnI Tyr-26 phosphorylation on myofilament deactivation, we measured the rate of calcium dissociation from TnC. Results demonstrate that filaments containing Tyr-26 pseudo-phosphorylated TnI accelerate the rate of calcium dissociation from TnC similar to that of TnI Ser-23/24. Finally, to assess functional integration of TnI Tyr-26 with Ser-23/24 phosphorylation, we generated recombinant TnI phospho-mimetic substitutions at all three residues. Our biochemical analyses demonstrated no additive effect on calcium sensitivity or calcium-sensitive force development imposed by Tyr-26 and Ser-23/24 phosphorylation integration. However, integration of Tyr-26 phosphorylation with pseudo-phosphorylated Ser-23/24 further accelerated thin filament deactivation. Our findings suggest that TnI Tyr-26 phosphorylation functions similarly to Ser-23/24N-terminal phosphorylation to decrease myofilament calcium sensitivity and accelerate myofilament relaxation. Furthermore, Tyr-26 phosphorylation can buffer the desensitization of Ser-23/24 phosphorylation while further accelerating thin filament deactivation. Therefore, the functional integration of TnI phosphorylation may be a common mechanism to modulate Ser-23/24 phosphorylation function.
Collapse
Affiliation(s)
- Hussam E Salhi
- The Department of Physiology and Cell Biology, The Ohio State University, Columbus, OH 43210, USA; The Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH 43210, USA
| | - Shane D Walton
- The Department of Physiology and Cell Biology, The Ohio State University, Columbus, OH 43210, USA; The Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH 43210, USA
| | - Nathan C Hassel
- The Department of Physiology and Cell Biology, The Ohio State University, Columbus, OH 43210, USA; The Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH 43210, USA
| | - Elizabeth A Brundage
- The Department of Physiology and Cell Biology, The Ohio State University, Columbus, OH 43210, USA; The Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH 43210, USA
| | - Pieter P de Tombe
- The Department of Cell and Molecular Physiology, Health Sciences Division, Loyola University Chicago, Maywood, IL 60153, USA
| | - Paul M L Janssen
- The Department of Physiology and Cell Biology, The Ohio State University, Columbus, OH 43210, USA; The Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH 43210, USA
| | - Jonathan P Davis
- The Department of Physiology and Cell Biology, The Ohio State University, Columbus, OH 43210, USA; The Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH 43210, USA
| | - Brandon J Biesiadecki
- The Department of Physiology and Cell Biology, The Ohio State University, Columbus, OH 43210, USA; The Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH 43210, USA.
| |
Collapse
|
32
|
Manders E, Bogaard HJ, Handoko ML, van de Veerdonk MC, Keogh A, Westerhof N, Stienen GJM, Dos Remedios CG, Humbert M, Dorfmüller P, Fadel E, Guignabert C, van der Velden J, Vonk-Noordegraaf A, de Man FS, Ottenheijm CAC. Contractile dysfunction of left ventricular cardiomyocytes in patients with pulmonary arterial hypertension. J Am Coll Cardiol 2014; 64:28-37. [PMID: 24998125 DOI: 10.1016/j.jacc.2014.04.031] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/27/2014] [Accepted: 04/16/2014] [Indexed: 10/25/2022]
Abstract
BACKGROUND After lung transplantation, increased left ventricular (LV) filling can lead to LV failure, increasing the risk of post-operative complications and mortality. LV dysfunction in pulmonary arterial hypertension (PAH) is characterized by a reduced LV ejection fraction and impaired diastolic function. OBJECTIVES The pathophysiology of LV dysfunction in PAH is incompletely understood. This study sought to assess the contribution of atrophy and contractility of cardiomyocytes to LV dysfunction in PAH patients. METHODS LV function was assessed by cardiac magnetic resonance imaging. In addition, LV biopsies were obtained in 9 PAH patients and 10 donors. The cross-sectional area (CSA) and force-generating capacity of isolated single cardiomyocytes was investigated. RESULTS Magnetic resonance imaging analysis revealed a significant reduction in LV ejection fraction in PAH patients, indicating a reduction in LV contractility. The CSA of LV cardiomyocytes of PAH patients was significantly reduced (~30%), indicating LV cardiomyocyte atrophy. The maximal force-generating capacity, normalized to cardiomyocyte CSA, was significantly reduced (~25%). Also, a reduction in the number of available myosin-based cross-bridges was found to cause the contractile weakness of cardiomyocytes. This finding was supported by protein analyses, which showed an ~30% reduction in the myosin/actin ratio in cardiomyocytes from PAH patients. Finally, the phosphorylation level of sarcomeric proteins was reduced in PAH patients, which was accompanied by increased calcium sensitivity of force generation. CONCLUSIONS The contractile function and the CSA of LV cardiomyocytes is substantially reduced in PAH patients. We propose that these changes contribute to the reduced in vivo contractility of the LV in PAH patients.
Collapse
Affiliation(s)
- Emmy Manders
- Department of Pulmonology, Vrije Universiteit (VU) University Medical Center, Amsterdam, the Netherlands; Department of Physiology, VU University Medical Center, Amsterdam, the Netherlands
| | - Harm-Jan Bogaard
- Department of Pulmonology, Vrije Universiteit (VU) University Medical Center, Amsterdam, the Netherlands
| | - M Louis Handoko
- Department of Physiology, VU University Medical Center, Amsterdam, the Netherlands; Cardiology Institute for Cardiovascular Research, VU University Medical Center, Amsterdam, the Netherlands
| | - Marielle C van de Veerdonk
- Department of Pulmonology, Vrije Universiteit (VU) University Medical Center, Amsterdam, the Netherlands
| | - Anne Keogh
- Heart Transplant Unit, St. Vincent's Hospital, Sydney, Australia
| | - Nico Westerhof
- Department of Pulmonology, Vrije Universiteit (VU) University Medical Center, Amsterdam, the Netherlands; Department of Physiology, VU University Medical Center, Amsterdam, the Netherlands
| | - Ger J M Stienen
- Department of Physiology, VU University Medical Center, Amsterdam, the Netherlands; Department of Physics and Astronomy, VU University, Amsterdam, the Netherlands
| | | | - Marc Humbert
- University of Paris-Sud, Faculté de Médecine, Le Kremlin-Bicêtre, France; Assistance Publique-Hôpitaux de Paris, Service de Pneumologie, Département Hospitalo-Universitaire, Thorax Innovation (DHU TORINO), Hôpital Bicêtre, Le Kremlin-Bicêtre, France; Inserm U999, Laboratoire d'Excellence en Recherche sur le Médicament et l'Innovation Thérapeutique (LabEx LERMIT), Centre Chirurgical Marie Lannelongue, Le Plessis-Robinson, France
| | - Peter Dorfmüller
- University of Paris-Sud, Faculté de Médecine, Le Kremlin-Bicêtre, France; Inserm U999, Laboratoire d'Excellence en Recherche sur le Médicament et l'Innovation Thérapeutique (LabEx LERMIT), Centre Chirurgical Marie Lannelongue, Le Plessis-Robinson, France; Service d'Anatomie Pathologique, Centre Chirurgical Marie Lannelongue, Le Plessis-Robinson, France
| | - Elie Fadel
- University of Paris-Sud, Faculté de Médecine, Le Kremlin-Bicêtre, France; Inserm U999, Laboratoire d'Excellence en Recherche sur le Médicament et l'Innovation Thérapeutique (LabEx LERMIT), Centre Chirurgical Marie Lannelongue, Le Plessis-Robinson, France; Service de Chirurgie Thoracique, Centre Chirurgical Marie Lannelongue, Le Plessis-Robinson, France
| | - Christophe Guignabert
- University of Paris-Sud, Faculté de Médecine, Le Kremlin-Bicêtre, France; Inserm U999, Laboratoire d'Excellence en Recherche sur le Médicament et l'Innovation Thérapeutique (LabEx LERMIT), Centre Chirurgical Marie Lannelongue, Le Plessis-Robinson, France
| | - Jolanda van der Velden
- Department of Physiology, VU University Medical Center, Amsterdam, the Netherlands; ICIN Netherlands Heart Institute, Utrecht, the Netherlands
| | - Anton Vonk-Noordegraaf
- Department of Pulmonology, Vrije Universiteit (VU) University Medical Center, Amsterdam, the Netherlands
| | - Frances S de Man
- Department of Pulmonology, Vrije Universiteit (VU) University Medical Center, Amsterdam, the Netherlands.
| | - Coen A C Ottenheijm
- Department of Physiology, VU University Medical Center, Amsterdam, the Netherlands.
| |
Collapse
|
33
|
Messer AE, Marston SB. Investigating the role of uncoupling of troponin I phosphorylation from changes in myofibrillar Ca(2+)-sensitivity in the pathogenesis of cardiomyopathy. Front Physiol 2014; 5:315. [PMID: 25202278 PMCID: PMC4142463 DOI: 10.3389/fphys.2014.00315] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2014] [Accepted: 08/02/2014] [Indexed: 12/12/2022] Open
Abstract
Contraction in the mammalian heart is controlled by the intracellular Ca(2+) concentration as it is in all striated muscle, but the heart has an additional signaling system that comes into play to increase heart rate and cardiac output during exercise or stress. β-adrenergic stimulation of heart muscle cells leads to release of cyclic-AMP and the activation of protein kinase A which phosphorylates key proteins in the sarcolemma, sarcoplasmic reticulum and contractile apparatus. Troponin I (TnI) and Myosin Binding Protein C (MyBP-C) are the prime targets in the myofilaments. TnI phosphorylation lowers myofibrillar Ca(2+)-sensitivity and increases the speed of Ca(2+)-dissociation and relaxation (lusitropic effect). Recent studies have shown that this relationship between Ca(2+)-sensitivity and TnI phosphorylation may be unstable. In familial cardiomyopathies, both dilated and hypertrophic (DCM and HCM), a mutation in one of the proteins of the thin filament often results in the loss of the relationship (uncoupling) and blunting of the lusitropic response. For familial dilated cardiomyopathy in thin filament proteins it has been proposed that this uncoupling is causative of the phenotype. Uncoupling has also been found in human heart tissue from patients with hypertrophic obstructive cardiomyopathy as a secondary effect. Recently, it has been found that Ca(2+)-sensitizing drugs can promote uncoupling, whilst one Ca(2+)-desensitizing drug Epigallocatechin 3-Gallate (EGCG) can reverse uncoupling. We will discuss recent findings about the role of uncoupling in the development of cardiomyopathies and the molecular mechanism of the process.
Collapse
Affiliation(s)
- Andrew E. Messer
- National Heart & Lung Institute, Imperial College LondonLondon, UK
| | | |
Collapse
|
34
|
Najafi A, Schlossarek S, van Deel ED, van den Heuvel N, Güçlü A, Goebel M, Kuster DWD, Carrier L, van der Velden J. Sexual dimorphic response to exercise in hypertrophic cardiomyopathy-associated MYBPC3-targeted knock-in mice. Pflugers Arch 2014; 467:1303-17. [PMID: 25010737 DOI: 10.1007/s00424-014-1570-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2014] [Revised: 06/27/2014] [Accepted: 06/27/2014] [Indexed: 01/02/2023]
Abstract
Hypertrophic cardiomyopathy (HCM), the most common genetic cardiac disorder, is frequently caused by mutations in MYBPC3, encoding cardiac myosin-binding protein C (cMyBP-C). Moreover, HCM is the leading cause of sudden cardiac death (SCD) in young athletes. Interestingly, SCD is more likely to occur in male than in female athletes. However, the pathophysiological mechanisms leading to sex-specific differences are poorly understood. Therefore, we studied the effect of sex and exercise on functional properties of the heart and sarcomeres in mice carrying a MYBPC3 point mutation (G > A transition in exon 6) associated with human HCM. Echocardiography followed by isometric force measurements in left ventricular (LV) membrane-permeabilized cardiomyocytes was performed in wild-type (WT) and heterozygous (HET) knock-in mice of both sex (N = 5 per group) in sedentary mice and mice that underwent an 8-week voluntary wheel-running exercise protocol. Isometric force measurements in single cardiomyocytes revealed a lower maximal force generation (F max) of the sarcomeres in male sedentary HET (13.0 ± 1.1 kN/m(2)) compared to corresponding WT (18.4 ± 1.8 kN/m(2)) male mice. Exercise induced a higher F max in HET male mice, while it did not affect HET females. Interestingly, a low cardiac troponin I bisphosphorylation, increased myofilament Ca(2+)-sensitivity, and LV hypertrophy were particularly observed in exercised HET females. In conclusion, in sedentary animals, contractile differences are seen between male and female HET mice. Male and female HET hearts adapted differently to a voluntary exercise protocol, indicating that physiological stimuli elicit a sexually dimorphic cardiac response in heterozygous MYBPC3-targeted knock-in mice.
Collapse
Affiliation(s)
- Aref Najafi
- Department of Physiology, VU University Medical Center, Room B-156, Van der Boechorstraat 7, 1081 BT, Amsterdam, The Netherlands,
| | | | | | | | | | | | | | | | | |
Collapse
|
35
|
Nixon BR, Walton SD, Zhang B, Brundage EA, Little SC, Ziolo MT, Davis JP, Biesiadecki BJ. Combined troponin I Ser-150 and Ser-23/24 phosphorylation sustains thin filament Ca(2+) sensitivity and accelerates deactivation in an acidic environment. J Mol Cell Cardiol 2014; 72:177-85. [PMID: 24657721 PMCID: PMC4075059 DOI: 10.1016/j.yjmcc.2014.03.010] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/01/2013] [Revised: 03/10/2014] [Accepted: 03/13/2014] [Indexed: 01/09/2023]
Abstract
The binding of Ca(2+) to troponin C (TnC) in the troponin complex is a critical step regulating the thin filament, the actin-myosin interaction and cardiac contraction. Phosphorylation of the troponin complex is a key regulatory mechanism to match cardiac contraction to demand. Here we demonstrate that phosphorylation of the troponin I (TnI) subunit is simultaneously increased at Ser-150 and Ser-23/24 during in vivo myocardial ischemia. Myocardial ischemia decreases intracellular pH resulting in depressed binding of Ca(2+) to TnC and impaired contraction. To determine the pathological relevance of these simultaneous TnI phosphorylations we measured individual TnI Ser-150 (S150D), Ser-23/24 (S23/24D) and combined (S23/24/150D) pseudo-phosphorylation effects on thin filament regulation at acidic pH similar to that in myocardial ischemia. Results demonstrate that while acidic pH decreased thin filament Ca(2+) binding to TnC regardless of TnI composition, TnI S150D attenuated this decrease rendering it similar to non-phosphorylated TnI at normal pH. The dissociation of Ca(2+) from TnC was unaltered by pH such that TnI S150D remained slow, S23/24D remained accelerated and the combined S23/24/150D remained accelerated. This effect of the combined TnI Ser-150 and Ser-23/24 pseudo-phosphorylations to maintain Ca(2+) binding while accelerating Ca(2+) dissociation represents the first post-translational modification of troponin by phosphorylation to both accelerate thin filament deactivation and maintain Ca(2+) sensitive activation. These data suggest that TnI Ser-150 phosphorylation induced attenuation of the pH-dependent decrease in Ca(2+) sensitivity and its combination with Ser-23/24 phosphorylation to maintain accelerated thin filament deactivation may impart an adaptive role to preserve contraction during acidic ischemia pH without slowing relaxation.
Collapse
Affiliation(s)
- Benjamin R Nixon
- Department of Physiology and Cell Biology, Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH 43210, USA
| | - Shane D Walton
- Department of Physiology and Cell Biology, Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH 43210, USA
| | - Bo Zhang
- Department of Physiology and Cell Biology, Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH 43210, USA
| | - Elizabeth A Brundage
- Department of Physiology and Cell Biology, Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH 43210, USA
| | - Sean C Little
- Department of Physiology and Cell Biology, Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH 43210, USA
| | - Mark T Ziolo
- Department of Physiology and Cell Biology, Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH 43210, USA
| | - Jonathan P Davis
- Department of Physiology and Cell Biology, Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH 43210, USA
| | - Brandon J Biesiadecki
- Department of Physiology and Cell Biology, Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH 43210, USA.
| |
Collapse
|
36
|
Rain S, Bos DDSG, Handoko ML, Westerhof N, Stienen G, Ottenheijm C, Goebel M, Dorfmüller P, Guignabert C, Humbert M, Bogaard HJ, Remedios CD, Saripalli C, Hidalgo CG, Granzier HL, Vonk-Noordegraaf A, van der Velden J, de Man FS. Protein changes contributing to right ventricular cardiomyocyte diastolic dysfunction in pulmonary arterial hypertension. J Am Heart Assoc 2014; 3:e000716. [PMID: 24895160 PMCID: PMC4309054 DOI: 10.1161/jaha.113.000716] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Background Right ventricular (RV) diastolic function is impaired in patients with pulmonary arterial hypertension (PAH). Our previous study showed that elevated cardiomyocyte stiffness and myofilament Ca2+ sensitivity underlie diastolic dysfunction in PAH. This study investigates protein modifications contributing to cellular diastolic dysfunction in PAH. Methods and Results RV samples from PAH patients undergoing heart‐lung transplantation were compared to non‐failing donors (Don). Titin stiffness contribution to RV diastolic dysfunction was determined by Western‐blot analyses using antibodies to protein‐kinase‐A (PKA), Cα (PKCα) and Ca2+/calmoduling‐dependent‐kinase (CamKIIδ) titin and phospholamban (PLN) phosphorylation sites: N2B (Ser469), PEVK (Ser170 and Ser26), and PLN (Thr17), respectively. PKA and PKCα sites were significantly less phosphorylated in PAH compared with donors (P<0.0001). To test the functional relevance of PKA‐, PKCα‐, and CamKIIδ‐mediated titin phosphorylation, we measured the stiffness of single RV cardiomyocytes before and after kinase incubation. PKA significantly decreased PAH RV cardiomyocyte diastolic stiffness, PKCα further increased stiffness while CamKIIδ had no major effect. CamKIIδ activation was determined indirectly by measuring PLN Thr17phosphorylation level. No significant changes were found between the groups. Myofilament Ca2+ sensitivity is mediated by sarcomeric troponin I (cTnI) phosphorylation. We observed increased unphosphorylated cTnI in PAH compared with donors (P<0.05) and reduced PKA‐mediated cTnI phosphorylation (Ser22/23) (P<0.001). Finally, alterations in Ca2+‐handling proteins contribute to RV diastolic dysfunction due to insufficient diastolic Ca2+ clearance. PAH SERCA2a levels and PLN phosphorylation were significantly reduced compared with donors (P<0.05). Conclusions Increased titin stiffness, reduced cTnI phosphorylation, and altered levels of phosphorylation of Ca2+ handling proteins contribute to RV diastolic dysfunction in PAH.
Collapse
Affiliation(s)
- Silvia Rain
- Department of Pulmonology, VU University Medical Center/Institute for Cardiovascular Research, Amsterdam, The Netherlands (S.R., D.S.G.B., N.W., H.J.B., A.V.N., F.S.M.) Department of Physiology, VU University Medical Center/Institute for Cardiovascular Research, Amsterdam, The Netherlands (S.R., L.H., N.W., G.S., C.O., M.G., J.V., F.S.M.)
| | - Denielli da Silva Goncalves Bos
- Department of Pulmonology, VU University Medical Center/Institute for Cardiovascular Research, Amsterdam, The Netherlands (S.R., D.S.G.B., N.W., H.J.B., A.V.N., F.S.M.)
| | - M Louis Handoko
- Department of Physiology, VU University Medical Center/Institute for Cardiovascular Research, Amsterdam, The Netherlands (S.R., L.H., N.W., G.S., C.O., M.G., J.V., F.S.M.) Department of Cardiology, VU University Medical Center/Institute for Cardiovascular Research, Amsterdam, The Netherlands (L.H.)
| | - Nico Westerhof
- Department of Pulmonology, VU University Medical Center/Institute for Cardiovascular Research, Amsterdam, The Netherlands (S.R., D.S.G.B., N.W., H.J.B., A.V.N., F.S.M.) Department of Physiology, VU University Medical Center/Institute for Cardiovascular Research, Amsterdam, The Netherlands (S.R., L.H., N.W., G.S., C.O., M.G., J.V., F.S.M.)
| | - Ger Stienen
- Department of Physiology, VU University Medical Center/Institute for Cardiovascular Research, Amsterdam, The Netherlands (S.R., L.H., N.W., G.S., C.O., M.G., J.V., F.S.M.) Department of Physics and Astronomy, VU University Medical Center/Institute for Cardiovascular Research, Amsterdam, The Netherlands (G.S.)
| | - Coen Ottenheijm
- Department of Physiology, VU University Medical Center/Institute for Cardiovascular Research, Amsterdam, The Netherlands (S.R., L.H., N.W., G.S., C.O., M.G., J.V., F.S.M.)
| | - Max Goebel
- Department of Physiology, VU University Medical Center/Institute for Cardiovascular Research, Amsterdam, The Netherlands (S.R., L.H., N.W., G.S., C.O., M.G., J.V., F.S.M.)
| | - Peter Dorfmüller
- Faculté de Médecine, Université Paris-Sud, Le Kremlin-Bicêtre, France (P.D., C.G., M.H.) Inserm U999, LabEx LERMIT, Centre Chirurgical Marie Lannelongue, Le Plessis Robinson, France (P.D., C.G., M.H.)
| | - Christophe Guignabert
- Faculté de Médecine, Université Paris-Sud, Le Kremlin-Bicêtre, France (P.D., C.G., M.H.) Inserm U999, LabEx LERMIT, Centre Chirurgical Marie Lannelongue, Le Plessis Robinson, France (P.D., C.G., M.H.)
| | - Marc Humbert
- Faculté de Médecine, Université Paris-Sud, Le Kremlin-Bicêtre, France (P.D., C.G., M.H.) Inserm U999, LabEx LERMIT, Centre Chirurgical Marie Lannelongue, Le Plessis Robinson, France (P.D., C.G., M.H.) Service d'Anatomie Pathologique, Centre Chirurgical Marie Lannelongue, Le Plessis Robinson, France (M.H.) Assistance Publique-Hôspitaux de Paris, Service de Pneumologie, Département Hôspital Universitaire, Thorax innovation, (DHU-TORINO), Hôpital Bicêtre, France (M.H.)
| | - Harm-Jan Bogaard
- Department of Pulmonology, VU University Medical Center/Institute for Cardiovascular Research, Amsterdam, The Netherlands (S.R., D.S.G.B., N.W., H.J.B., A.V.N., F.S.M.)
| | - Cris Dos Remedios
- Muscle Research Unit, Discipline of Anatomy & Histology, Bosch Institute, The University of Sydney, Sydney, Australia (C.R.)
| | - Chandra Saripalli
- Sarver Molecular Cardiovascular Research Program, Department of Physiology, University of Arizona, Tucson, AZ, The Netherlands (C.S., C.G.H., H.L.G.)
| | - Carlos G Hidalgo
- Sarver Molecular Cardiovascular Research Program, Department of Physiology, University of Arizona, Tucson, AZ, The Netherlands (C.S., C.G.H., H.L.G.)
| | - Henk L Granzier
- Sarver Molecular Cardiovascular Research Program, Department of Physiology, University of Arizona, Tucson, AZ, The Netherlands (C.S., C.G.H., H.L.G.)
| | - Anton Vonk-Noordegraaf
- Department of Pulmonology, VU University Medical Center/Institute for Cardiovascular Research, Amsterdam, The Netherlands (S.R., D.S.G.B., N.W., H.J.B., A.V.N., F.S.M.)
| | - Jolanda van der Velden
- Department of Physiology, VU University Medical Center/Institute for Cardiovascular Research, Amsterdam, The Netherlands (S.R., L.H., N.W., G.S., C.O., M.G., J.V., F.S.M.) ICIN - The Netherlands Heart Institute, Amsterdam, The Netherlands (J.V.)
| | - Frances S de Man
- Department of Pulmonology, VU University Medical Center/Institute for Cardiovascular Research, Amsterdam, The Netherlands (S.R., D.S.G.B., N.W., H.J.B., A.V.N., F.S.M.) Department of Physiology, VU University Medical Center/Institute for Cardiovascular Research, Amsterdam, The Netherlands (S.R., L.H., N.W., G.S., C.O., M.G., J.V., F.S.M.)
| |
Collapse
|
37
|
Milani-Nejad N, Janssen PML. Small and large animal models in cardiac contraction research: advantages and disadvantages. Pharmacol Ther 2014; 141:235-49. [PMID: 24140081 PMCID: PMC3947198 DOI: 10.1016/j.pharmthera.2013.10.007] [Citation(s) in RCA: 305] [Impact Index Per Article: 30.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2013] [Accepted: 08/15/2013] [Indexed: 12/22/2022]
Abstract
The mammalian heart is responsible for not only pumping blood throughout the body but also adjusting this pumping activity quickly depending upon sudden changes in the metabolic demands of the body. For the most part, the human heart is capable of performing its duties without complications; however, throughout many decades of use, at some point this system encounters problems. Research into the heart's activities during healthy states and during adverse impacts that occur in disease states is necessary in order to strategize novel treatment options to ultimately prolong and improve patients' lives. Animal models are an important aspect of cardiac research where a variety of cardiac processes and therapeutic targets can be studied. However, there are differences between the heart of a human being and an animal and depending on the specific animal, these differences can become more pronounced and in certain cases limiting. There is no ideal animal model available for cardiac research, the use of each animal model is accompanied with its own set of advantages and disadvantages. In this review, we will discuss these advantages and disadvantages of commonly used laboratory animals including mouse, rat, rabbit, canine, swine, and sheep. Since the goal of cardiac research is to enhance our understanding of human health and disease and help improve clinical outcomes, we will also discuss the role of human cardiac tissue in cardiac research. This review will focus on the cardiac ventricular contractile and relaxation kinetics of humans and animal models in order to illustrate these differences.
Collapse
Affiliation(s)
- Nima Milani-Nejad
- Department of Physiology and Cell Biology and D. Davis Heart Lung Institute, College of Medicine, The Ohio State University, OH, USA
| | - Paul M L Janssen
- Department of Physiology and Cell Biology and D. Davis Heart Lung Institute, College of Medicine, The Ohio State University, OH, USA.
| |
Collapse
|
38
|
Sequeira V, Witjas-Paalberends ER, Kuster DWD, van der Velden J. Cardiac myosin-binding protein C: hypertrophic cardiomyopathy mutations and structure-function relationships. Pflugers Arch 2013; 466:201-6. [PMID: 24240729 DOI: 10.1007/s00424-013-1400-3] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2013] [Revised: 10/30/2013] [Accepted: 10/31/2013] [Indexed: 01/05/2023]
Abstract
Cardiac myosin-binding protein C (cMyBP-C) research has been characterized by two waves. Initial interest was piqued by its discovery in 1973 as a contaminant of myosin preparations from skeletal muscle. The second wave started in 1995 by the discovery that mutations in the gene encoding cMyBP-C cause hypertrophic cardiomyopathy (HCM). In this review, we will address what is known of cMyBP-C's role as a regulator of contraction as well as its role in HCM.
Collapse
Affiliation(s)
- Vasco Sequeira
- Department of Physiology, Institute for Cardiovascular Research (ICaR-VU), VU University Medical Center, van der Boechorststraat 7, 1081, BT, Amsterdam, The Netherlands
| | | | | | | |
Collapse
|
39
|
Kooij V, Zhang P, Piersma SR, Sequeira V, Boontje NM, Wijnker PJM, Jiménez CR, Jaquet KE, dos Remedios C, Murphy AM, Van Eyk JE, van der Velden J, Stienen GJM. PKCα-specific phosphorylation of the troponin complex in human myocardium: a functional and proteomics analysis. PLoS One 2013; 8:e74847. [PMID: 24116014 PMCID: PMC3792062 DOI: 10.1371/journal.pone.0074847] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2013] [Accepted: 08/07/2013] [Indexed: 11/18/2022] Open
Abstract
Aims Protein kinase Cα (PKCα) is one of the predominant PKC isoforms that phosphorylate cardiac troponin. PKCα is implicated in heart failure and serves as a potential therapeutic target, however, the exact consequences for contractile function in human myocardium are unclear. This study aimed to investigate the effects of PKCα phosphorylation of cardiac troponin (cTn) on myofilament function in human failing cardiomyocytes and to resolve the potential targets involved. Methods and Results Endogenous cTn from permeabilized cardiomyocytes from patients with end-stage idiopathic dilated cardiomyopathy was exchanged (∼69%) with PKCα-treated recombinant human cTn (cTn (DD+PKCα)). This complex has Ser23/24 on cTnI mutated into aspartic acids (D) to rule out in vitro cross-phosphorylation of the PKA sites by PKCα. Isometric force was measured at various [Ca2+] after exchange. The maximal force (Fmax) in the cTn (DD+PKCα) group (17.1±1.9 kN/m2) was significantly reduced compared to the cTn (DD) group (26.1±1.9 kN/m2). Exchange of endogenous cTn with cTn (DD+PKCα) increased Ca2+-sensitivity of force (pCa50 = 5.59±0.02) compared to cTn (DD) (pCa50 = 5.51±0.02). In contrast, subsequent PKCα treatment of the cells exchanged with cTn (DD+PKCα) reduced pCa50 to 5.45±0.02. Two PKCα-phosphorylated residues were identified with mass spectrometry: Ser198 on cTnI and Ser179 on cTnT, although phosphorylation of Ser198 is very low. Using mass spectrometry based-multiple reaction monitoring, the extent of phosphorylation of the cTnI sites was quantified before and after treatment with PKCα and showed the highest phosphorylation increase on Thr143. Conclusion PKCα-mediated phosphorylation of the cTn complex decreases Fmax and increases myofilament Ca2+-sensitivity, while subsequent treatment with PKCα in situ decreased myofilament Ca2+-sensitivity. The known PKC sites as well as two sites which have not been previously linked to PKCα are phosphorylated in human cTn complex treated with PKCα with a high degree of specificity for Thr143.
Collapse
Affiliation(s)
- Viola Kooij
- Laboratory for Physiology, Institute for Cardiovascular Research, VU Medical Center, Amsterdam, The Netherlands
- Johns Hopkins Bayview Proteomics Center, Department of Medicine, School of Medicine, Johns Hopkins University, Baltimore, Maryland, United States of America
- * E-mail:
| | - Pingbo Zhang
- Johns Hopkins Bayview Proteomics Center, Department of Medicine, School of Medicine, Johns Hopkins University, Baltimore, Maryland, United States of America
| | - Sander R. Piersma
- OncoProteomics Laboratory, Department of Medical Oncology, VU Medical Center, Amsterdam, The Netherlands
| | - Vasco Sequeira
- Laboratory for Physiology, Institute for Cardiovascular Research, VU Medical Center, Amsterdam, The Netherlands
| | - Nicky M. Boontje
- Laboratory for Physiology, Institute for Cardiovascular Research, VU Medical Center, Amsterdam, The Netherlands
| | - Paul J. M. Wijnker
- Laboratory for Physiology, Institute for Cardiovascular Research, VU Medical Center, Amsterdam, The Netherlands
| | - Connie R. Jiménez
- OncoProteomics Laboratory, Department of Medical Oncology, VU Medical Center, Amsterdam, The Netherlands
| | - Kornelia E. Jaquet
- St Josef-Hospital/Bergmannsheil, Clinic of the Ruhr-University of Bochum, Bochum, Germany
| | - Cris dos Remedios
- Muscle Research Unit, Institute for Biomedical Research, The University of Sydney, Sydney, Australia
| | - Anne M. Murphy
- Institute of Molecular Cardiobiology, Department of Pediatrics, School of Medical, Johns Hopkins University, Baltimore, Maryland, United States of America
| | - Jennifer E. Van Eyk
- Johns Hopkins Bayview Proteomics Center, Department of Medicine, School of Medicine, Johns Hopkins University, Baltimore, Maryland, United States of America
| | - Jolanda van der Velden
- Laboratory for Physiology, Institute for Cardiovascular Research, VU Medical Center, Amsterdam, The Netherlands
| | - Ger JM. Stienen
- Laboratory for Physiology, Institute for Cardiovascular Research, VU Medical Center, Amsterdam, The Netherlands
- Department of Physics and Astronomy, VU University, Amsterdam, The Netherlands
| |
Collapse
|
40
|
Posttranslational modifications of cardiac troponin T: An overview. J Mol Cell Cardiol 2013; 63:47-56. [DOI: 10.1016/j.yjmcc.2013.07.004] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/21/2013] [Revised: 06/18/2013] [Accepted: 07/08/2013] [Indexed: 12/22/2022]
|
41
|
Hanft LM, Biesiadecki BJ, McDonald KS. Length dependence of striated muscle force generation is controlled by phosphorylation of cTnI at serines 23/24. J Physiol 2013; 591:4535-47. [PMID: 23836688 PMCID: PMC3784197 DOI: 10.1113/jphysiol.2013.258400] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2013] [Accepted: 07/02/2013] [Indexed: 01/24/2023] Open
Abstract
According to the Frank-Starling relationship, greater end-diastolic volume increases ventricular output. The Frank-Starling relationship is based, in part, on the length-tension relationship in cardiac myocytes. Recently, we identified a dichotomy in the steepness of length-tension relationships in mammalian cardiac myocytes that was dependent upon protein kinase A (PKA)-induced myofibrillar phosphorylation. Because PKA has multiple myofibrillar substrates including titin, myosin-binding protein-C and cardiac troponin I (cTnI), we sought to define if phosphorylation of one of these molecules could control length-tension relationships. We focused on cTnI as troponin can be exchanged in permeabilized striated muscle cell preparations, and tested the hypothesis that phosphorylation of cTnI modulates length dependence of force generation. For these experiments, we exchanged unphosphorylated recombinant cTn into either a rat cardiac myocyte preparation or a skinned slow-twitch skeletal muscle fibre. In all cases unphosphorylated cTn yielded a shallow length-tension relationship, which was shifted to a steep relationship after PKA treatment. Furthermore, exchange with cTn having cTnI serines 23/24 mutated to aspartic acids to mimic phosphorylation always shifted a shallow length-tension relationship to a steep relationship. Overall, these results indicate that phosphorylation of cTnI serines 23/24 is a key regulator of length dependence of force generation in striated muscle.
Collapse
Affiliation(s)
- Laurin M Hanft
- K. S. McDonald: Department of Medical Pharmacology & Physiology, University of Missouri, Columbia, MO 65212, USA.
| | | | | |
Collapse
|
42
|
Chen H, Hwang H, McKee LAK, Perez JN, Regan JA, Constantopoulos E, Lafleur B, Konhilas JP. Temporal and morphological impact of pressure overload in transgenic FHC mice. Front Physiol 2013; 4:205. [PMID: 23986715 PMCID: PMC3753457 DOI: 10.3389/fphys.2013.00205] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2013] [Accepted: 07/19/2013] [Indexed: 01/19/2023] Open
Abstract
Although familial hypertrophic cardiomyopathy (FHC) is characterized as cardiac disease in the absence of overt stressors, disease penetrance, and pathological progression largely depend on modifying factors. Accordingly, pressure overload by transverse aortic constriction (TAC) was induced in 2-month-old, male mice with and without a FHC (R403Q) mutation in α-myosin heavy chain. A significantly greater number of FHC mice (n = 8) than wild-type (WT) mice (n = 5) died during the 9-week study period. TAC induced a significant increase in cardiac mass whether measured at 2 or 9 weeks post-TAC in both WT and FHC mice, albeit to a different extent. However, the temporal and morphological trajectory of ventricular remodeling was impacted by the FHC transgene. Both WT and FHC hearts responded to TAC with an early (2 weeks post-TAC) and significant augmentation of the relative wall thickness (RWT) indicative of concentric hypertrophy. By 9 weeks post-TAC, RWT decreased in WT hearts (eccentric hypertrophy) but remained elevated in FHC hearts. WT hearts following TAC demonstrated enhanced cardiac function as measured by the end-systolic pressure-volume relationship, pre-load recruitable stroke work (PRSW), and myocardial relaxation indicative of compensatory hypertrophy. Similarly, TAC induced differential histological and cellular remodeling; TAC reduced expression of the sarcoplasmic reticulum Ca(2+)-ATPase (2a) (SERCA2a; 2 and 9 weeks) and phospholamban (PLN; 2 weeks) but increased PLN phosphorylation (2 weeks) and β-myosin heavy chain (β-MyHC; 9 weeks) in WT hearts. FHC-TAC hearts showed increased β-MyHC (2 and 9 weeks) and a late (9 weeks) decrease in PLN expression concomitant with a significant increase in PLN phosphorylation. We conclude that FHC hearts respond to TAC induced pressure overload with increased premature death, severe concentric hypertrophy, and a differential ability to undergo morphological, functional, or cellular remodeling compared to WT hearts.
Collapse
Affiliation(s)
- Hao Chen
- Molecular Cardiovascular Research Program, Department of Physiology, University of Arizona Tucson, AZ, USA
| | | | | | | | | | | | | | | |
Collapse
|
43
|
Kirk JA, Zhang P, Murphy AM, Van Eyk JE. Troponin I alterations detected by multiple-reaction monitoring: how might this impact the study of heart failure? Expert Rev Proteomics 2013; 10:5-8. [PMID: 23414352 DOI: 10.1586/epr.12.77] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
44
|
McKee LA, Chen H, Regan JA, Behunin SM, Walker JW, Walker JS, Konhilas JP. Sexually dimorphic myofilament function and cardiac troponin I phosphospecies distribution in hypertrophic cardiomyopathy mice. Arch Biochem Biophys 2013; 535:39-48. [PMID: 23352598 PMCID: PMC3640654 DOI: 10.1016/j.abb.2012.12.023] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2012] [Revised: 12/12/2012] [Accepted: 12/14/2012] [Indexed: 11/16/2022]
Abstract
The pathological progression of hypertrophic cardiomyopathy (HCM) is sexually dimorphic such that male HCM mice develop phenotypic indicators of cardiac disease well before female HCM mice. Here, we hypothesized that alterations in myofilament function underlies, in part, this sex dimorphism in HCM disease development. Firstly, 10-12month female HCM (harboring a mutant [R403Q] myosin heavy chain) mice presented with proportionately larger hearts than male HCM mice. Next, we determined Ca(2+)-sensitive tension development in demembranated cardiac trabeculae excised from 10-12month female and male HCM mice. Whereas HCM did not impact Ca(2+)-sensitive tension development in male trabeculae, female HCM trabeculae were more sensitive to Ca(2+) than wild-type (WT) counterparts and both WT and HCM males. We hypothesized that the underlying cause of this sex difference in Ca(2+)-sensitive tension development was due to changes in Ca(2+) handling and sarcomeric proteins, including expression of SR Ca(2+) ATPase (2a) (SERCA2a), β-myosin heavy chain (β-MyHC) and post-translational modifications of myofilament proteins. Female HCM hearts showed an elevation of SERCA2a and β-MyHC protein whereas male HCM hearts showed a similar elevation of β-MyHC protein but a reduced level of cardiac troponin T (cTnT) phosphorylation. We also measured the distribution of cardiac troponin I (cTnI) phosphospecies using phosphate-affinity SDS-PAGE. The distribution of cTnI phosphospecies depended on sex and HCM. In conclusion, female and male HCM mice display sex dimorphic myofilament function that is accompanied by a sex- and HCM-dependent distribution of sarcomeric proteins and cTnI phosphospecies.
Collapse
Affiliation(s)
- Laurel A.K. McKee
- Department of Physiology, Sarver Molecular Cardiovascular Research Program, University of Arizona, 1501 N. Campbell Ave., Tucson, AZ 85724, USA
| | - Hao Chen
- Department of Physiology, Sarver Molecular Cardiovascular Research Program, University of Arizona, 1501 N. Campbell Ave., Tucson, AZ 85724, USA
| | - Jessica A. Regan
- Department of Physiology, Sarver Molecular Cardiovascular Research Program, University of Arizona, 1501 N. Campbell Ave., Tucson, AZ 85724, USA
| | - Samantha M. Behunin
- Department of Physiology, Sarver Molecular Cardiovascular Research Program, University of Arizona, 1501 N. Campbell Ave., Tucson, AZ 85724, USA
| | - Jeffery W. Walker
- Department of Physiology, Sarver Molecular Cardiovascular Research Program, University of Arizona, 1501 N. Campbell Ave., Tucson, AZ 85724, USA
| | - John S. Walker
- University of Colorado Denver, Department of Medicine/Cardiology, Aurora, CO 80045, USA
| | - John P. Konhilas
- Department of Physiology, Sarver Molecular Cardiovascular Research Program, University of Arizona, 1501 N. Campbell Ave., Tucson, AZ 85724, USA
| |
Collapse
|
45
|
Wang X, Wang J, Su M, Wang C, Chen J, Wang H, Song L, Zou Y, Zhang L, Zhang Y, Hui R. TNNI3K, a cardiac-specific kinase, promotes physiological cardiac hypertrophy in transgenic mice. PLoS One 2013; 8:e58570. [PMID: 23472207 PMCID: PMC3589374 DOI: 10.1371/journal.pone.0058570] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2012] [Accepted: 02/06/2013] [Indexed: 01/09/2023] Open
Abstract
Purpose Protein kinase plays an essential role in controlling cardiac growth and hypertrophic remodeling. The cardiac troponin I-interacting kinase (TNNI3K), a novel cardiac specific kinase, is associated with cardiomyocyte hypertrophy. However, the precise function of TNNI3K in regulating cardiac remodeling has remained controversial. Methods and Results In a rat model of cardiac hypertrophy generated by transverse aortic constriction, myocardial TNNI3K expression was significantly increased by 1.62 folds (P<0.05) after constriction for 15 days. To investigate the role of TNNI3K in cardiac hypertrophy, we generated transgenic mouse lines with overexpression of human TNNI3K specifically in the heart. At the age of 3 months, the high-copy-number TNNI3K transgenic mice demonstrated a phenotype of concentric hypertrophy with increased heart weight normalized to body weight (1.31 fold, P<0.01). Echocardiography and non-invasive hemodynamic assessments showed enhanced cardiac function. No necrosis or myocyte disarray was observed in the heart of TNNI3K transgenic mice. This concentric hypertrophy maintained up to 12 months of age without cardiac dysfunction. The phospho amino acid analysis revealed that TNNI3K is a protein-tyrosine kinase. The yeast two-hybrid screen and co-immunoprecipitation assay identified cTnI as a target for TNNI3K. Moreover, TNNI3K overexpression induced cTnI phosphorylation at Ser22/Ser23 in vivo and in vitro, suggesting that TNNI3K is a novel upstream regulator for cTnI phosphorylation. Conclusion TNNI3K promotes a concentric hypertrophy with enhancement of cardiac function via regulating the phosphorylation of cTnI. TNNI3K could be a potential therapeutic target for preventing from heart failure.
Collapse
Affiliation(s)
- Xiaojian Wang
- Sino-German Laboratory for Molecular Medicine, State Key Laboratory of Cardiovascular Disease, FuWai Hospital & Cardiovascular Institute, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, People's Republic of China
| | - Jizheng Wang
- Sino-German Laboratory for Molecular Medicine, State Key Laboratory of Cardiovascular Disease, FuWai Hospital & Cardiovascular Institute, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, People's Republic of China
| | - Ming Su
- Sino-German Laboratory for Molecular Medicine, State Key Laboratory of Cardiovascular Disease, FuWai Hospital & Cardiovascular Institute, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, People's Republic of China
| | - Changxin Wang
- Sino-German Laboratory for Molecular Medicine, State Key Laboratory of Cardiovascular Disease, FuWai Hospital & Cardiovascular Institute, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, People's Republic of China
| | - Jingzhou Chen
- Sino-German Laboratory for Molecular Medicine, State Key Laboratory of Cardiovascular Disease, FuWai Hospital & Cardiovascular Institute, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, People's Republic of China
| | - Hu Wang
- Sino-German Laboratory for Molecular Medicine, State Key Laboratory of Cardiovascular Disease, FuWai Hospital & Cardiovascular Institute, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, People's Republic of China
| | - Lei Song
- Department of Cardiology, State Key Laboratory of Cardiovascular Disease, FuWai Hospital & Cardiovascular Institute, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, People's Republic of China
| | - Yubao Zou
- Department of Cardiology, State Key Laboratory of Cardiovascular Disease, FuWai Hospital & Cardiovascular Institute, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, People's Republic of China
| | - Lianfeng Zhang
- Key Laboratory of Human Disease Comparative Medicine, Ministry of Health, Institute of Laboratory Animal Science, Chinese Academy of Medical Sciences and Comparative Medical Center, Peking Union Medical College, Beijing, People's Republic of China
| | - Youyi Zhang
- Institute of Vascular Medicine, Peking University Third Hospital, Beijing, People's Republic of China
| | - Rutai Hui
- Sino-German Laboratory for Molecular Medicine, State Key Laboratory of Cardiovascular Disease, FuWai Hospital & Cardiovascular Institute, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, People's Republic of China
- * E-mail:
| |
Collapse
|
46
|
Zhang P, Kirk JA, Ji W, dos Remedios CG, Kass DA, Van Eyk JE, Murphy AM. Multiple reaction monitoring to identify site-specific troponin I phosphorylated residues in the failing human heart. Circulation 2012; 126:1828-37. [PMID: 22972900 DOI: 10.1161/circulationaha.112.096388] [Citation(s) in RCA: 112] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Human cardiac troponin I is known to be phosphorylated at multiple amino acid residues by several kinases. Advances in mass spectrometry allow sensitive detection of known and novel phosphorylation sites and measurement of the level of phosphorylation simultaneously at each site in myocardial samples. METHODS AND RESULTS On the basis of in silico prediction and liquid chromatography/mass spectrometry data, 14 phosphorylation sites on cardiac troponin I, including 6 novel residues (S4, S5, Y25, T50, T180, S198), were assessed in explanted hearts from end-stage heart failure transplantation patients with ischemic heart disease or idiopathic dilated cardiomyopathy and compared with samples obtained from nonfailing donor hearts (n=10 per group). Thirty mass spectrometry-based multiple reaction monitoring quantitative tryptic peptide assays were developed for each phosphorylatable and corresponding nonphosphorylated site. The results show that in heart failure there is a decrease in the extent of phosphorylation of the known protein kinase A sites (S22, S23) and other newly discovered phosphorylation sites located in the N-terminal extension of cardiac troponin I (S4, S5, Y25), an increase in phosphorylation of the protein kinase C sites (S41, S43, T142), and an increase in phosphorylation of the IT-arm domain residues (S76, T77) and C-terminal domain novel phosphorylation sites of cardiac troponin I (S165, T180, S198). In a canine dyssynchronous heart failure model, enhanced phosphorylation at 3 novel sites was found to decline toward control after resynchronization therapy. CONCLUSIONS Selective, functionally significant phosphorylation alterations occurred on individual residues of cardiac troponin I in heart failure, likely reflecting an imbalance in kinase/phosphatase activity. Such changes can be reversed by cardiac resynchronization.
Collapse
Affiliation(s)
- Pingbo Zhang
- Department of Medicine, Division of Cardiology, Johns Hopkins University, Baltimore, MD, USA
| | | | | | | | | | | | | |
Collapse
|
47
|
Dirkx E, Cazorla O, Schwenk RW, Lorenzen-Schmidt I, Sadayappan S, Van Lint J, Carrier L, van Eys GJJM, Glatz JFC, Luiken JJFP. Protein kinase D increases maximal Ca2+-activated tension of cardiomyocyte contraction by phosphorylation of cMyBP-C-Ser315. Am J Physiol Heart Circ Physiol 2012; 303:H323-31. [PMID: 22636676 DOI: 10.1152/ajpheart.00749.2011] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Cardiac myosin-binding protein C (cMyBP-C) is involved in the regulation of cardiac myofilament contraction. Recent evidence showed that protein kinase D (PKD) is one of the kinases that phosphorylate cMyBP-C. However, the mechanism by which PKD-induced cMyBP-C phosphorylation affects cardiac contractile responses is not known. Using immunoprecipitation, we showed that, in contracting cardiomyocytes, PKD binds to cMyBP-C and phosphorylates it at Ser(315). The effect of PKD-mediated phosphorylation of cMyBP-C on cardiac myofilament function was investigated in permeabilized ventricular myocytes, isolated from wild-type (WT) and from cMyBP-C knockout (KO) mice, incubated in the presence of full-length active PKD. In WT myocytes, PKD increased both myofilament Ca(2+) sensitivity (pCa(50)) and maximal Ca(2+)-activated tension of contraction (T(max)). In cMyBP-C KO skinned myocytes, PKD increased pCa(50) but did not alter T(max). This suggests that cMyBP-C is not involved in PKD-mediated sensitization of myofilaments to Ca(2+) but is essential for PKD-induced increase in T(max). Furthermore, the phosphorylation of both PKD-Ser(916) and cMyBP-C-Ser(315) was contraction frequency-dependent, suggesting that PKD-mediated cMyBP-C phosphorylation is operational primarily during periods of increased contractile activity. Thus, during high contraction frequency, PKD facilitates contraction of cardiomyocytes by increasing Ca(2+) sensitivity and by an increased T(max) through phosphorylation of cMyBP-C.
Collapse
Affiliation(s)
- Ellen Dirkx
- Department of Molecular Genetics, Cardiovascular Research Institute Maastricht, Maastricht University, the Netherlands.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
48
|
van Dijk SJ, Paalberends ER, Najafi A, Michels M, Sadayappan S, Carrier L, Boontje NM, Kuster DWD, van Slegtenhorst M, Dooijes D, dos Remedios C, ten Cate FJ, Stienen GJM, van der Velden J. Contractile dysfunction irrespective of the mutant protein in human hypertrophic cardiomyopathy with normal systolic function. Circ Heart Fail 2011; 5:36-46. [PMID: 22178992 DOI: 10.1161/circheartfailure.111.963702] [Citation(s) in RCA: 100] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Hypertrophic cardiomyopathy (HCM), typically characterized by asymmetrical left ventricular hypertrophy, frequently is caused by mutations in sarcomeric proteins. We studied if changes in sarcomeric properties in HCM depend on the underlying protein mutation. METHODS AND RESULTS Comparisons were made between cardiac samples from patients carrying a MYBPC3 mutation (MYBPC3(mut); n=17), mutation negative HCM patients without an identified sarcomere mutation (HCM(mn); n=11), and nonfailing donors (n=12). All patients had normal systolic function, but impaired diastolic function. Protein expression of myosin binding protein C (cMyBP-C) was significantly lower in MYBPC3(mut) by 33±5%, and similar in HCM(mn) compared with donor. cMyBP-C phosphorylation in MYBPC3(mut) was similar to donor, whereas it was significantly lower in HCM(mn). Troponin I phosphorylation was lower in both patient groups compared with donor. Force measurements in single permeabilized cardiomyocytes demonstrated comparable sarcomeric dysfunction in both patient groups characterized by lower maximal force generating capacity in MYBPC3(mut) and HCM(mn,) compared with donor (26.4±2.9, 28.0±3.7, and 37.2±2.3 kN/m(2), respectively), and higher myofilament Ca(2+)-sensitivity (EC(50)=2.5±0.2, 2.4±0.2, and 3.0±0.2 μmol/L, respectively). The sarcomere length-dependent increase in Ca(2+)-sensitivity was significantly smaller in both patient groups compared with donor (ΔEC(50): 0.46±0.04, 0.37±0.05, and 0.75±0.07 μmol/L, respectively). Protein kinase A treatment restored myofilament Ca(2+)-sensitivity and length-dependent activation in both patient groups to donor values. CONCLUSIONS Changes in sarcomere function reflect the clinical HCM phenotype rather than the specific MYBPC3 mutation. Hypocontractile sarcomeres are a common deficit in human HCM with normal systolic left ventricular function and may contribute to HCM disease progression.
Collapse
Affiliation(s)
- Sabine J van Dijk
- Laboratory for Physiology, Institute for Cardiovascular Research, VU University Medical Center, Amsterdam, The Netherlands
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
49
|
Kuster DWD, Bawazeer AC, Zaremba R, Goebel M, Boontje NM, van der Velden J. Cardiac myosin binding protein C phosphorylation in cardiac disease. J Muscle Res Cell Motil 2011; 33:43-52. [PMID: 22127559 PMCID: PMC3351594 DOI: 10.1007/s10974-011-9280-7] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2011] [Accepted: 11/23/2011] [Indexed: 12/14/2022]
Abstract
Perturbations in sarcomeric function may in part underlie systolic and diastolic dysfunction of the failing heart. Sarcomeric dysfunction has been ascribed to changes in phosphorylation status of sarcomeric proteins caused by an altered balance between intracellular kinases and phosphatases during the development of cardiac disease. In the present review we discuss changes in phosphorylation of the thick filament protein myosin binding protein C (cMyBP-C) reported in failing myocardium, with emphasis on phosphorylation changes observed in familial hypertrophic cardiomyopathy caused by mutations in MYBPC3. Moreover, we will discuss assays which allow to distinguish between functional consequences of mutant sarcomeric proteins and (mal)adaptive changes in sarcomeric protein phosphorylation.
Collapse
MESH Headings
- Animals
- Calcium/metabolism
- Cardiomyopathy, Hypertrophic, Familial/genetics
- Cardiomyopathy, Hypertrophic, Familial/metabolism
- Cardiomyopathy, Hypertrophic, Familial/pathology
- Carrier Proteins/genetics
- Carrier Proteins/metabolism
- Cyclic AMP-Dependent Protein Kinases/metabolism
- Heart Failure, Systolic/metabolism
- Heart Failure, Systolic/pathology
- Humans
- Mice
- Mice, Transgenic
- Mutation
- Myocardium/metabolism
- Myocardium/pathology
- Myocytes, Cardiac/metabolism
- Myocytes, Cardiac/pathology
- Phosphoric Monoester Hydrolases/metabolism
- Phosphorylation
- Sarcomeres/metabolism
- Sarcomeres/pathology
Collapse
Affiliation(s)
- Diederik W D Kuster
- Department of Physiology, VU University Medical Center, Amsterdam, The Netherlands.
| | | | | | | | | | | |
Collapse
|
50
|
Protein phosphatase 2A affects myofilament contractility in non-failing but not in failing human myocardium. J Muscle Res Cell Motil 2011; 32:221-33. [PMID: 21959857 PMCID: PMC3205269 DOI: 10.1007/s10974-011-9261-x] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2011] [Accepted: 09/09/2011] [Indexed: 02/04/2023]
Abstract
Protein phosphatase (PP) type 2A is a multifunctional serine/threonine phosphatase that is involved in cardiac excitation-contraction coupling. The PP2A core enzyme is a dimer, consisting of a catalytic C and a scaffolding A subunit, which is targeted to several cardiac proteins by a regulatory B subunit. At present, it is controversial whether PP2A and its subunits play a critical role in end-stage human heart failure. Here we report that the application of purified PP2AC significantly increased the Ca2+-sensitivity (ΔpCa50=0.05±0.01) of the contractile apparatus in isolated skinned myocytes of non-failing (NF) hearts. A higher phosphorylation of troponin I (cTnI) was found at protein kinase A sites (Ser23/24) in NF compared to failing myocardium. The basal Ca2+-responsiveness of myofilaments was enhanced in myocytes of ischemic (ICM, ΔpCa50=0.10±0.03) and dilated (DCM, ΔpCa50=0.06±0.04) cardiomyopathy compared to NF. However, in contrast to NF myocytes the treatment with PP2AC did not shift force-pCa relationships in failing myocytes. The higher basal Ca2+-sensitivity in failing myocytes coincided with a reduced protein expression of PP2AC in left ventricular tissue from patients suffering from ICM and DCM (by 50 and 56% compared to NF, respectively). However, PP2A activity was unchanged in failing hearts despite an increase of both total PP and PP1 activity. The expression of PP2AB56α was also decreased by 51 and 62% in ICM and DCM compared to NF, respectively. The phosphorylation of cTnI at Ser23/24 was reduced by 66 and 49% in ICM and DCM compared to NF hearts, respectively. Our results demonstrate that PP2A increases myofilament Ca2+-sensitivity in NF human hearts, most likely via cTnI dephosphorylation. This effect is not present in failing hearts, probably due to the lower baseline cTnI phosphorylation in failing compared to non-failing hearts.
Collapse
|