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Solaro RJ, Goldspink PH, Wolska BM. Emerging Concepts of Mechanisms Controlling Cardiac Tension: Focus on Familial Dilated Cardiomyopathy (DCM) and Sarcomere-Directed Therapies. Biomedicines 2024; 12:999. [PMID: 38790961 PMCID: PMC11117855 DOI: 10.3390/biomedicines12050999] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2024] [Revised: 04/28/2024] [Accepted: 04/30/2024] [Indexed: 05/26/2024] Open
Abstract
Novel therapies for the treatment of familial dilated cardiomyopathy (DCM) are lacking. Shaping research directions to clinical needs is critical. Triggers for the progression of the disorder commonly occur due to specific gene variants that affect the production of sarcomeric/cytoskeletal proteins. Generally, these variants cause a decrease in tension by the myofilaments, resulting in signaling abnormalities within the micro-environment, which over time result in structural and functional maladaptations, leading to heart failure (HF). Current concepts support the hypothesis that the mutant sarcomere proteins induce a causal depression in the tension-time integral (TTI) of linear preparations of cardiac muscle. However, molecular mechanisms underlying tension generation particularly concerning mutant proteins and their impact on sarcomere molecular signaling are currently controversial. Thus, there is a need for clarification as to how mutant proteins affect sarcomere molecular signaling in the etiology and progression of DCM. A main topic in this controversy is the control of the number of tension-generating myosin heads reacting with the thin filament. One line of investigation proposes that this number is determined by changes in the ratio of myosin heads in a sequestered super-relaxed state (SRX) or in a disordered relaxed state (DRX) poised for force generation upon the Ca2+ activation of the thin filament. Contrasting evidence from nanometer-micrometer-scale X-ray diffraction in intact trabeculae indicates that the SRX/DRX states may have a lesser role. Instead, the proposal is that myosin heads are in a basal OFF state in relaxation then transfer to an ON state through a mechano-sensing mechanism induced during early thin filament activation and increasing thick filament strain. Recent evidence about the modulation of these mechanisms by protein phosphorylation has also introduced a need for reconsidering the control of tension. We discuss these mechanisms that lead to different ideas related to how tension is disturbed by levels of mutant sarcomere proteins linked to the expression of gene variants in the complex landscape of DCM. Resolving the various mechanisms and incorporating them into a unified concept is crucial for gaining a comprehensive understanding of DCM. This deeper understanding is not only important for diagnosis and treatment strategies with small molecules, but also for understanding the reciprocal signaling processes that occur between cardiac myocytes and their micro-environment. By unraveling these complexities, we can pave the way for improved therapeutic interventions for managing DCM.
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Affiliation(s)
- R. John Solaro
- Department of Physiology and Biophysics, Center for Cardiovascular Research, University of Illinois at Chicago, Chicago, IL 60612, USA; (P.H.G.); (B.M.W.)
| | - Paul H. Goldspink
- Department of Physiology and Biophysics, Center for Cardiovascular Research, University of Illinois at Chicago, Chicago, IL 60612, USA; (P.H.G.); (B.M.W.)
| | - Beata M. Wolska
- Department of Physiology and Biophysics, Center for Cardiovascular Research, University of Illinois at Chicago, Chicago, IL 60612, USA; (P.H.G.); (B.M.W.)
- Department of Medicine, Section of Cardiology, University of Illinois at Chicago, Chicago, IL 60612, USA
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Salyer LG, Salhi HE, Brundage EA, Shettigar V, Sturgill SL, Zanella H, Templeton B, Abay E, Emmer KM, Lowe J, Rafael-Fortney JA, Parinandi N, Foster DB, McKinsey TA, Woulfe KC, Ziolo MT, Biesiadecki BJ. Troponin I Tyrosine Phosphorylation Beneficially Accelerates Diastolic Function. Circ Res 2024; 134:33-45. [PMID: 38095088 PMCID: PMC10872382 DOI: 10.1161/circresaha.123.323132] [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: 05/23/2023] [Accepted: 11/28/2023] [Indexed: 01/06/2024]
Abstract
BACKGROUND A healthy heart is able to modify its function and increase relaxation through post-translational modifications of myofilament proteins. While there are known examples of serine/threonine kinases directly phosphorylating myofilament proteins to modify heart function, the roles of tyrosine (Y) phosphorylation to directly modify heart function have not been demonstrated. The myofilament protein TnI (troponin I) is the inhibitory subunit of the troponin complex and is a key regulator of cardiac contraction and relaxation. We previously demonstrated that TnI-Y26 phosphorylation decreases calcium-sensitive force development and accelerates calcium dissociation, suggesting a novel role for tyrosine kinase-mediated TnI-Y26 phosphorylation to regulate cardiac relaxation. Therefore, we hypothesize that increasing TnI-Y26 phosphorylation will increase cardiac relaxation in vivo and be beneficial during pathological diastolic dysfunction. METHODS The signaling pathway involved in TnI-Y26 phosphorylation was predicted in silico and validated by tyrosine kinase activation and inhibition in primary adult murine cardiomyocytes. To investigate how TnI-Y26 phosphorylation affects cardiac muscle, structure, and function in vivo, we developed a novel TnI-Y26 phosphorylation-mimetic mouse that was subjected to echocardiography, pressure-volume loop hemodynamics, and myofibril mechanical studies. TnI-Y26 phosphorylation-mimetic mice were further subjected to the nephrectomy/DOCA (deoxycorticosterone acetate) model of diastolic dysfunction to investigate the effects of increased TnI-Y26 phosphorylation in disease. RESULTS Src tyrosine kinase is sufficient to phosphorylate TnI-Y26 in cardiomyocytes. TnI-Y26 phosphorylation accelerates in vivo relaxation without detrimental structural or systolic impairment. In a mouse model of diastolic dysfunction, TnI-Y26 phosphorylation is beneficial and protects against the development of disease. CONCLUSIONS We have demonstrated that tyrosine kinase phosphorylation of TnI is a novel mechanism to directly and beneficially accelerate myocardial relaxation in vivo.
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Affiliation(s)
- Lorien G Salyer
- Department of Physiology and Cell Biology, Davis Heart and Lung Research Institute (L.G.S., H.E.S., E.A.B., V.S., S.L.S., H.Z., B.T., E.A., J.L., J.A.R.-F., M.T.Z., B.J.B.), Ohio State University, Columbus
| | - Hussam E Salhi
- Department of Physiology and Cell Biology, Davis Heart and Lung Research Institute (L.G.S., H.E.S., E.A.B., V.S., S.L.S., H.Z., B.T., E.A., J.L., J.A.R.-F., M.T.Z., B.J.B.), Ohio State University, Columbus
| | - Elizabeth A Brundage
- Department of Physiology and Cell Biology, Davis Heart and Lung Research Institute (L.G.S., H.E.S., E.A.B., V.S., S.L.S., H.Z., B.T., E.A., J.L., J.A.R.-F., M.T.Z., B.J.B.), Ohio State University, Columbus
| | - Vikram Shettigar
- Department of Physiology and Cell Biology, Davis Heart and Lung Research Institute (L.G.S., H.E.S., E.A.B., V.S., S.L.S., H.Z., B.T., E.A., J.L., J.A.R.-F., M.T.Z., B.J.B.), Ohio State University, Columbus
| | - Sarah L Sturgill
- Department of Physiology and Cell Biology, Davis Heart and Lung Research Institute (L.G.S., H.E.S., E.A.B., V.S., S.L.S., H.Z., B.T., E.A., J.L., J.A.R.-F., M.T.Z., B.J.B.), Ohio State University, Columbus
| | - Helena Zanella
- Department of Physiology and Cell Biology, Davis Heart and Lung Research Institute (L.G.S., H.E.S., E.A.B., V.S., S.L.S., H.Z., B.T., E.A., J.L., J.A.R.-F., M.T.Z., B.J.B.), Ohio State University, Columbus
| | - Benjamin Templeton
- Department of Physiology and Cell Biology, Davis Heart and Lung Research Institute (L.G.S., H.E.S., E.A.B., V.S., S.L.S., H.Z., B.T., E.A., J.L., J.A.R.-F., M.T.Z., B.J.B.), Ohio State University, Columbus
| | - Eaman Abay
- Department of Physiology and Cell Biology, Davis Heart and Lung Research Institute (L.G.S., H.E.S., E.A.B., V.S., S.L.S., H.Z., B.T., E.A., J.L., J.A.R.-F., M.T.Z., B.J.B.), Ohio State University, Columbus
| | - Kathryn M Emmer
- University Laboratory Animal Resources (K.M.E.), Ohio State University, Columbus
| | - Jeovanna Lowe
- Department of Physiology and Cell Biology, Davis Heart and Lung Research Institute (L.G.S., H.E.S., E.A.B., V.S., S.L.S., H.Z., B.T., E.A., J.L., J.A.R.-F., M.T.Z., B.J.B.), Ohio State University, Columbus
| | - Jill A Rafael-Fortney
- Department of Physiology and Cell Biology, Davis Heart and Lung Research Institute (L.G.S., H.E.S., E.A.B., V.S., S.L.S., H.Z., B.T., E.A., J.L., J.A.R.-F., M.T.Z., B.J.B.), Ohio State University, Columbus
| | - Narasimham Parinandi
- Division of Pulmonary, Critical Care and Sleep Medicine (N.P.), Ohio State University, Columbus
| | - D Brian Foster
- Division of Cardiology, Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, MD (D.B.F.)
| | - Timothy A McKinsey
- Department of Medicine, Division of Cardiology (T.A.M., K.C.W.), University of Colorado Anschutz Medical Campus, Aurora
- Consortium for Fibrosis Research and Translation (T.A.M.), University of Colorado Anschutz Medical Campus, Aurora
| | - Kathleen C Woulfe
- Department of Medicine, Division of Cardiology (T.A.M., K.C.W.), University of Colorado Anschutz Medical Campus, Aurora
| | - Mark T Ziolo
- Department of Physiology and Cell Biology, Davis Heart and Lung Research Institute (L.G.S., H.E.S., E.A.B., V.S., S.L.S., H.Z., B.T., E.A., J.L., J.A.R.-F., M.T.Z., B.J.B.), Ohio State University, Columbus
| | - Brandon J Biesiadecki
- Department of Physiology and Cell Biology, Davis Heart and Lung Research Institute (L.G.S., H.E.S., E.A.B., V.S., S.L.S., H.Z., B.T., E.A., J.L., J.A.R.-F., M.T.Z., B.J.B.), Ohio State University, Columbus
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Langa P, Marszalek RJ, Warren CM, Chowdhury SK, Halas M, Batra A, Rafael-Clyke K, Bacon A, Goldspink PH, Solaro RJ, Wolska BM. Altered coronary artery function, arteriogenesis and endothelial YAP signaling in postnatal hypertrophic cardiomyopathy. Front Physiol 2023; 14:1136852. [PMID: 37064918 PMCID: PMC10102353 DOI: 10.3389/fphys.2023.1136852] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Accepted: 03/13/2023] [Indexed: 04/03/2023] Open
Abstract
Introduction: Hypertrophic cardiomyopathy (HCM) is a cardiovascular genetic disease caused largely by sarcomere protein mutations. Gaps in our understanding exist as to how maladaptive sarcomeric biophysical signals are transduced to intra- and extracellular compartments leading to HCM progression. To investigate early HCM progression, we focused on the onset of myofilament dysfunction during neonatal development and examined cardiac dynamics, coronary vascular structure and function, and mechano-transduction signaling in mice harboring a thin-filament HCM mutation. Methods: We studied postnatal days 7-28 (P7-P28) in transgenic (TG) TG-cTnT-R92Q and non-transgenic (NTG) mice using skinned fiber mechanics, echocardiography, biochemistry, histology, and immunohistochemistry. Results: At P7, skinned myofiber bundles exhibited an increased Ca2+-sensitivity (pCa50 TG: 5.97 ± 0.04, NTG: 5.84 ± 0.01) resulting from cTnT-R92Q expression on a background of slow skeletal (fetal) troponin I and α/β myosin heavy chain isoform expression. Despite the transition to adult isoform expressions between P7-P14, the increased Ca2+- sensitivity persisted through P28 with no apparent differences in gross morphology among TG and NTG hearts. At P7 significant diastolic dysfunction was accompanied by coronary flow perturbation (mean diastolic velocity, TG: 222.5 ± 18.81 mm/s, NTG: 338.7 ± 28.07 mm/s) along with localized fibrosis (TG: 4.36% ± 0.44%, NTG: 2.53% ± 0.47%). Increased phosphorylation of phospholamban (PLN) was also evident indicating abnormalities in Ca2+ homeostasis. By P14 there was a decline in arteriolar cross-sectional area along with an expansion of fibrosis (TG: 9.72% ± 0.73%, NTG: 2.72% ± 0.2%). In comparing mechano-transduction signaling in the coronary arteries, we uncovered an increase in endothelial YAP expression with a decrease in its nuclear to cytosolic ratio at P14 in TG hearts, which was reversed by P28. Conclusion: We conclude that those early mechanisms that presage hypertrophic remodeling in HCM include defective biophysical signals within the sarcomere that drive diastolic dysfunction, impacting coronary flow dynamics, defective arteriogenesis and fibrosis. Changes in mechano-transduction signaling between the different cellular compartments contribute to the pathogenesis of HCM.
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Affiliation(s)
- Paulina Langa
- Department of Physiology and Biophysics, College of Medicine, University of Illinois at Chicago, Chicago, IL, United States
- Center for Cardiovascular Research, College of Medicine, University of Illinois at Chicago, Chicago, IL, United States
| | - Richard J. Marszalek
- Department of Physiology and Biophysics, College of Medicine, University of Illinois at Chicago, Chicago, IL, United States
- Center for Cardiovascular Research, College of Medicine, University of Illinois at Chicago, Chicago, IL, United States
| | - Chad M. Warren
- Department of Physiology and Biophysics, College of Medicine, University of Illinois at Chicago, Chicago, IL, United States
- Center for Cardiovascular Research, College of Medicine, University of Illinois at Chicago, Chicago, IL, United States
| | - Shamim K. Chowdhury
- Department of Physiology and Biophysics, College of Medicine, University of Illinois at Chicago, Chicago, IL, United States
| | - Monika Halas
- Department of Physiology and Biophysics, College of Medicine, University of Illinois at Chicago, Chicago, IL, United States
| | - Ashley Batra
- Department of Physiology and Biophysics, College of Medicine, University of Illinois at Chicago, Chicago, IL, United States
| | - Koreena Rafael-Clyke
- Department of Physiology and Biophysics, College of Medicine, University of Illinois at Chicago, Chicago, IL, United States
| | - Angelie Bacon
- Department of Physiology and Biophysics, College of Medicine, University of Illinois at Chicago, Chicago, IL, United States
| | - Paul H. Goldspink
- Department of Physiology and Biophysics, College of Medicine, University of Illinois at Chicago, Chicago, IL, United States
- Center for Cardiovascular Research, College of Medicine, University of Illinois at Chicago, Chicago, IL, United States
| | - R. John Solaro
- Department of Physiology and Biophysics, College of Medicine, University of Illinois at Chicago, Chicago, IL, United States
- Center for Cardiovascular Research, College of Medicine, University of Illinois at Chicago, Chicago, IL, United States
| | - Beata M. Wolska
- Department of Physiology and Biophysics, College of Medicine, University of Illinois at Chicago, Chicago, IL, United States
- Center for Cardiovascular Research, College of Medicine, University of Illinois at Chicago, Chicago, IL, United States
- Department of Medicine, Division of Cardiology, College of Medicine, University of Illinois at Chicago, Chicago, IL, United States
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4
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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.
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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.
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Phillips EH, Bindokas VP, Jung D, Teamer J, Kitajewski JK, Solaro RJ, Wolska BM, Lee SSY. Three-dimensional spatial quantitative analysis of cardiac lymphatics in the mouse heart. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.01.526338. [PMID: 36778334 PMCID: PMC9915594 DOI: 10.1101/2023.02.01.526338] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Objective 3D microscopy and image data analysis are necessary for studying the morphology of cardiac lymphatic vessels (LyVs) and association with other cell types. We aimed to develop a methodology for 3D multiplexed lightsheet microscopy and highly sensitive and quantitative image analysis to identify pathological remodeling in the 3D morphology of LyVs in young adult mouse hearts with familial hypertrophic cardiomyopathy (HCM). Methods We developed a 3D lightsheet microscopy workflow providing a quick turn-around (as few as 5-6 days), multiplex fluorescence detection, and preservation of LyV structure and epitope markers. Hearts from non-transgenic (NTG) and transgenic (TG) HCM mice were arrested in diastole, retrograde perfused, immunolabeled, optically cleared, and imaged. We built an image processing pipeline to quantify LyV morphological parameters at the chamber and branch levels. Results Chamber-specific pathological alterations of LyVs were identified, but most significantly in the right atrium (RA). TG hearts had a higher volume fraction of ER-TR7 + fibroblasts and reticular fibers. In the RA, we found associations between ER-TR7 + volume fraction and both LyV segment density and median diameter. Conclusions This workflow and study enabled multi-scale analysis of pathological changes in cardiac LyVs of young adult mice, inviting ideas for research on LyVs in cardiac disease.
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Prill K, Jones MR, Steffensen K, Teng GZ, Dawson JF. Increasing the calcium sensitivity of muscle using trifluoperazine-induced manipulations in silico, in vitro and in vivo systems. Arch Biochem Biophys 2023; 735:109521. [PMID: 36657606 DOI: 10.1016/j.abb.2023.109521] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Revised: 01/09/2023] [Accepted: 01/14/2023] [Indexed: 01/18/2023]
Abstract
Many therapeutics for cardiomyopathy treat the symptoms of the disease rather than the underlying mechanism. The mechanism of cardiomyopathy onset is believed to include two means: calcium sensitivity changes and myosin activity alteration. Trifluoperazine is a compound that binds troponin, and other components of the calcium pathway, which impacts calcium regulation of contraction. Here, the ability of TFP to shift calcium sensitivity was examined in vitro with purified proteins and the impact of TFP on heart function was assessed in vivo using embryonic zebrafish. The binding of TFP to troponin was modeled in silico and a model of zebrafish troponin was generated. TFP increased regulated cardiac actomyosin activity in vitro and elevated embryonic zebrafish heart rates at effective drug concentrations. Troponin structural changes predicted in silico suggest altered protein interactions within thin filaments that would affect the regulation of heart function.
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Affiliation(s)
- Kendal Prill
- From the Department of Molecular & Cellular Biology, University of Guelph; Centre for Cardiovascular Investigations, University of Guelph, Guelph, ON, N1G 2W1, Canada.
| | - Michael R Jones
- From the Department of Molecular & Cellular Biology, University of Guelph; Centre for Cardiovascular Investigations, University of Guelph, Guelph, ON, N1G 2W1, Canada.
| | - Karl Steffensen
- From the Department of Molecular & Cellular Biology, University of Guelph; Centre for Cardiovascular Investigations, University of Guelph, Guelph, ON, N1G 2W1, Canada.
| | - Grace Zi Teng
- From the Department of Molecular & Cellular Biology, University of Guelph; Centre for Cardiovascular Investigations, University of Guelph, Guelph, ON, N1G 2W1, Canada
| | - John F Dawson
- From the Department of Molecular & Cellular Biology, University of Guelph; Centre for Cardiovascular Investigations, University of Guelph, Guelph, ON, N1G 2W1, Canada
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Marston S, Pinto JR. Suppression of lusitropy as a disease mechanism in cardiomyopathies. Front Cardiovasc Med 2023; 9:1080965. [PMID: 36698941 PMCID: PMC9870330 DOI: 10.3389/fcvm.2022.1080965] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Accepted: 12/19/2022] [Indexed: 01/11/2023] Open
Abstract
In cardiac muscle the action of adrenaline on β1 receptors of heart muscle cells is essential to adjust cardiac output to the body's needs. Adrenergic activation leads to enhanced contractility (inotropy), faster heart rate (chronotropy) and faster relaxation (lusitropy), mainly through activation of protein kinase A (PKA). Efficient enhancement of heart output under stress requires all of these responses to work together. Lusitropy is essential for shortening the heartbeat when heart rate increases. It therefore follows that, if the lusitropic response is not present, heart function under stress will be compromised. Current literature suggests that lusitropy is primarily achieved due to PKA phosphorylation of troponin I (TnI) and phospholamban (PLB). It has been well documented that PKA-induced phosphorylation of TnI releases Ca2+ from troponin C faster and increases the rate of cardiac muscle relaxation, while phosphorylation of PLB increases SERCA activity, speeding up Ca2+ removal from the cytoplasm. In this review we consider the current scientific evidences for the connection between suppression of lusitropy and cardiac dysfunction in the context of mutations in phospholamban and thin filament proteins that are associated with cardiomyopathies. We will discuss what advances have been made into understanding the physiological mechanism of lusitropy due to TnI and PLB phosphorylation and its suppression by mutations and we will evaluate the evidence whether lack of lusitropy is sufficient to cause cardiomyopathy, and under what circumstances, and consider the range of pathologies associated with loss of lusitropy. Finally, we will discuss whether suppressed lusitropy due to mutations in thin filament proteins can be therapeutically restored.
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Affiliation(s)
- Steven Marston
- National Heart and Lung Institute, Imperial College London, London, United Kingdom
| | - Jose Renato Pinto
- Department of Biomedical Sciences, Florida State University College of Medicine, Tallahassee, FL, United States
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Langa P, Wolska BM, Solaro RJ. The Hippo Signaling Pathway as a Drug Target in Familial Dilated Cardiomyopathy. INTERNATIONAL JOURNAL OF DRUG DISCOVERY AND PHARMACOLOGY 2022; 1:4. [PMID: 38818406 PMCID: PMC11139043 DOI: 10.53941/ijddp.v1i1.189] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/01/2024]
Abstract
We focus here on the Hippo pathway in the hierarchical sensing and modulation of the mechanical state of the adult heart in health and disease. The Hippo pathway interrogates the micro-environment of cardiac myocytes providing surveillance of the mechanical state with engagement of signaling pathways critical to homeostasis of cardiac development, remodeling, and function and vulnerable to pathologies. Our discussion centers on Hippo signaling in the altered mechanical state instigated by variants of genes expressing mutant sarcomere proteins that trigger a progression to dilated cardiomyopathy (familial DCM). There is an unmet need for therapies in DCM. Recent progress in the discovery of small molecules that target Hippo signaling and are intended for use in cardiac disorders provides leads for modifying Hippo in DCM. As we emphasize, identifying useful targets in DCM requires in depth understanding of cell specific Hippo signaling in the cardiac micro-environment.
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Affiliation(s)
- Paulina Langa
- Department of Physiology and Biophysics and the Center for Cardiovascular Research,University of Illinois at Chicago, Chicago, IL,USA
| | - Beata M. Wolska
- Department of Physiology and Biophysics and the Center for Cardiovascular Research,University of Illinois at Chicago, Chicago, IL,USA
- Department of Medicine, Division of Cardiology, College of Medicine, University of Illinois at Chicago, Chicago, IL, USA
| | - R. John Solaro
- Department of Physiology and Biophysics and the Center for Cardiovascular Research,University of Illinois at Chicago, Chicago, IL,USA
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Tamargo J, Tamargo M, Caballero R. Hypertrophic cardiomyopathy: an up-to-date snapshot of the clinical drug development pipeline. Expert Opin Investig Drugs 2022; 31:1027-1052. [PMID: 36062808 DOI: 10.1080/13543784.2022.2113374] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
INTRODUCTION Hypertrophic cardiomyopathy (HCM) is a complex cardiac disease with highly variable phenotypic expression and clinical course most often caused by sarcomeric gene mutations resulting in left ventricular hypertrophy, fibrosis, hypercontractility, and diastolic dysfunction. For almost 60 years, HCM has remained an orphan disease and still lacks a disease-specific treatment. AREAS COVERED This review summarizes recent preclinical and clinical trials with repurposed drugs and new emerging pharmacological and gene-based therapies for the treatment of HCM. EXPERT OPINION The off-label drugs routinely used alleviate symptoms but do not target the core pathophysiology of HCM or prevent or revert the phenotype. Recent advances in the genetics and pathophysiology of HCM led to the development of cardiac myosin adenosine triphosphatase inhibitors specifically directed to counteract the hypercontractility associated with HCM-causing mutations. Mavacamten, the first drug specifically developed for HCM successfully tested in a phase 3 trial, represents the major advance for the treatment of HCM. This opens new horizons for the development of novel drugs targeting HCM molecular substrates which hopefully modify the natural history of the disease. The role of current drugs in development and genetic-based approaches for the treatment of HCM are also discussed.
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Affiliation(s)
- Juan Tamargo
- Department of Pharmacology and Toxicology, School of Medicine, Universidad Complutense, Instituto de Investigación Sanitaria Gregorio Marañón, CIBERCV, 28040 Madrid, Spain
| | - María Tamargo
- Department of Cardiology, Hospital Universitario Gregorio Marañón, Instituto de Investigación Sanitaria Gregorio Marañón, CIBERCV, Doctor Esquerdo, 46, 28007 Madrid, Spain
| | - Ricardo Caballero
- Department of Pharmacology and Toxicology, School of Medicine, Universidad Complutense, Instituto de Investigación Sanitaria Gregorio Marañón, CIBERCV, 28040 Madrid, Spain
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10
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Shen H, Dong SY, Ren MS, Wang R. Ventricular arrhythmia and sudden cardiac death in hypertrophic cardiomyopathy: From bench to bedside. Front Cardiovasc Med 2022; 9:949294. [PMID: 36061538 PMCID: PMC9433716 DOI: 10.3389/fcvm.2022.949294] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Accepted: 07/14/2022] [Indexed: 11/13/2022] Open
Abstract
Patients with hypertrophic cardiomyopathy (HCM) mostly experience minimal symptoms throughout their lifetime, and some individuals have an increased risk of ventricular arrhythmias and sudden cardiac death (SCD). How to identify patients with a higher risk of ventricular arrythmias and SCD is the priority in HCM research. The American College of Cardiology/American Heart Association (ACC/AHA) and the European Society of Cardiology (ESC) both recommend the use of risk algorithms to identify patients at high risk of ventricular arrhythmias, to be selected for implantation of implantable cardioverters/defibrillators (ICDs) for primary prevention of SCD, although major discrepancies exist. The present SCD risk scoring systems cannot accurately identify early-stage HCM patients with modest structural remodeling and mild disease manifestations. Unfortunately, SCD events could occur in young asymptomatic HCM patients and even as initial symptoms, prompting the determination of new risk factors for SCD. This review summarizes the studies based on patients' surgical specimens, transgenic animals, and patient-derived induced pluripotent stem cells (hiPSCs) to explore the possible molecular mechanism of ventricular arrhythmia and SCD. Ion channel remodeling, Ca2+ homeostasis abnormalities, and increased myofilament Ca2+ sensitivity may contribute to changes in action potential duration (APD), reentry circuit formation, and trigger activities, such as early aferdepolarization (EAD) or delayed afterdepolarization (DAD), leading to ventricular arrhythmia in HCM. Besides the ICD implantation, novel drugs represented by the late sodium current channel inhibitor and myosin inhibitor also shed light on the prevention of HCM-related arrhythmias. The ideal prevention strategy of SCD in early-stage HCM patients needs to be combined with gene screening, hiPSC-CM testing, machine learning, and advanced ECG studies, thus achieving individualized SCD prevention.
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Affiliation(s)
- Hua Shen
- Division of Adult Cardiac Surgery, Department of Cardiovascular Medicine, The Sixth Medical Center, Chinese PLA General Hospital, Beijing, China
| | - Shi-Yong Dong
- Department of Cardiovascular Surgery, The First Medical Center, Chinese PLA General Hospital, Beijing, China
| | - Ming-Shi Ren
- Division of Adult Cardiac Surgery, Department of Cardiovascular Medicine, The Sixth Medical Center, Chinese PLA General Hospital, Beijing, China
- Graduate School, Chinese PLA General Hospital & Chinese PLA Medical School, Beijing, China
| | - Rong Wang
- Division of Adult Cardiac Surgery, Department of Cardiovascular Medicine, The Sixth Medical Center, Chinese PLA General Hospital, Beijing, China
- Department of Cardiovascular Surgery, The First Medical Center, Chinese PLA General Hospital, Beijing, China
- *Correspondence: Rong Wang
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11
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Solaro RJ. Widely cited publications of Michael Bárány in 1964 and 1967 as tipping points in understanding myosin molecular motors. Arch Biochem Biophys 2022; 727:109319. [PMID: 35709967 DOI: 10.1016/j.abb.2022.109319] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2022] [Accepted: 06/06/2022] [Indexed: 11/02/2022]
Abstract
In 1964 Michael Bárány and colleagues published a paper ((M. Bárány, E. Gaetjens, K. Bárány, Karp E. Arch Biochem Biophys 106(1964)280-93. http://10.1016/0003-9861(64)90,189-4)) that has been one of the most cited papers in Archives of Biochemistry and Biophysics. This was followed in 1967 by another most cited paper (M. Bárány. J Gen Physiol 50(1967)197-218. https://doi.org/10.1085/jgp.50.6.197). I have commemorated these achievements as tipping points in the understanding of myosin motors in muscle function. Tipping points are generally defined as a temporal point in which a series of progressive advances (in this case the understanding of the relations between myosin ATP hydrolysis and muscle function) inspire more expansive, wide-ranging, significant changes. I first concisely summarize the background against which the papers came to publication as well as the unimaginable personal challenges faced by Michael and Kate Bárány. A final section summarizes the impact of these publications as key steps in the progression of contemporary understanding of diverse control of myosin ATPase activity with focus on the thick filaments in cardiac homeostasis, disorders, and as targets for therapeutic applications in translational investigations.
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Affiliation(s)
- R John Solaro
- Department of Physiology and Biophysics and the Center for Cardiovascular Research, College of Medicine, University of Illinois at Chicago, 835 South Wolcott Avenue, Chicago, IL, USA.
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12
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Truncation of the N-terminus of cardiac troponin I initiates adaptive remodeling of the myocardial proteosome via phosphorylation of mechano-sensitive signaling pathways. Mol Cell Biochem 2022; 477:1803-1815. [PMID: 35316461 DOI: 10.1007/s11010-022-04414-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Accepted: 03/10/2022] [Indexed: 10/18/2022]
Abstract
The cardiac isoform of troponin I has a unique N-terminal extension (~ 1-30 amino acids), which contributes to the modulation of cardiac contraction and relaxation. Hearts of various species including humans produce a truncated variant of cardiac troponin I (cTnI-ND) deleting the first ~ 30 amino acids as an adaption in pathophysiological conditions. In this study, we investigated the impact of cTnI-ND chronic expression in transgenic mouse hearts compared to wildtype (WT) controls (biological n = 8 in each group). We aimed to determine the global phosphorylation effects of cTnI-ND on the cardiac proteome, thereby determining the signaling pathways that have an impact on cardiac function. The samples were digested and isobarically labeled and equally mixed for relative quantification via nanoLC-MS/MS. The peptides were then enriched for phospho-peptides and bioinformatic analysis was done with Ingenuity Pathway Analysis (IPA). We found approximately 77% replacement of the endogenous intact cTnI with cTnI-ND in the transgenic mouse hearts with 1674 phospho-proteins and 2971 non-modified proteins. There were 73 significantly altered phospho-proteins; bioinformatic analysis identified the top canonical pathways as associated with integrin, protein kinase A, RhoA, and actin cytoskeleton signaling. Among the 73 phospho-proteins compared to controls cTnI-ND hearts demonstrated a significant decrease in paxillin and YAP1, which are known to play a role in cell mechano-sensing pathways. Our data indicate that cTnI-ND modifications in the sarcomere are sufficient to initiate changes in the phospho-signaling profile that may underly the chronic-adaptive response associated with cTnI cleavage in response to stressors by modifying mechano-sensitive signaling pathways.
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13
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Glavaški M, Velicki L. Shared Molecular Mechanisms of Hypertrophic Cardiomyopathy and Its Clinical Presentations: Automated Molecular Mechanisms Extraction Approach. Life (Basel) 2021; 11:life11080785. [PMID: 34440529 PMCID: PMC8398249 DOI: 10.3390/life11080785] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Revised: 07/23/2021] [Accepted: 07/30/2021] [Indexed: 12/30/2022] Open
Abstract
Hypertrophic cardiomyopathy (HCM) is the most common inherited cardiovascular disease with a prevalence of 1 in 500 people and varying clinical presentations. Although there is much research on HCM, underlying molecular mechanisms are poorly understood, and research on the molecular mechanisms of its specific clinical presentations is scarce. Our aim was to explore the molecular mechanisms shared by HCM and its clinical presentations through the automated extraction of molecular mechanisms. Molecular mechanisms were congregated by a query of the INDRA database, which aggregates knowledge from pathway databases and combines it with molecular mechanisms extracted from abstracts and open-access full articles by multiple machine-reading systems. The molecular mechanisms were extracted from 230,072 articles on HCM and 19 HCM clinical presentations, and their intersections were found. Shared molecular mechanisms of HCM and its clinical presentations were represented as networks; the most important elements in the intersections’ networks were found, centrality scores for each element of each network calculated, networks with reduced level of noise generated, and cooperatively working elements detected in each intersection network. The identified shared molecular mechanisms represent possible mechanisms underlying different HCM clinical presentations. Applied methodology produced results consistent with the information in the scientific literature.
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Affiliation(s)
- Mila Glavaški
- Faculty of Medicine, University of Novi Sad, Hajduk Veljkova 3, 21000 Novi Sad, Serbia;
- Correspondence: or
| | - Lazar Velicki
- Faculty of Medicine, University of Novi Sad, Hajduk Veljkova 3, 21000 Novi Sad, Serbia;
- Institute of Cardiovascular Diseases Vojvodina, Put Doktora Goldmana 4, 21204 Sremska Kamenica, Serbia
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14
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Stătescu C, Enachi Ș, Ureche C, Țăpoi L, Anghel L, Șalaru D, Pleșoianu C, Bostan M, Marcu D, Ovanez Balasanian M, Sascău RA. Pushing the Limits of Medical Management in HCM: A Review of Current Pharmacological Therapy Options. Int J Mol Sci 2021; 22:ijms22137218. [PMID: 34281272 PMCID: PMC8268685 DOI: 10.3390/ijms22137218] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 06/27/2021] [Accepted: 06/29/2021] [Indexed: 11/16/2022] Open
Abstract
Hypertrophic cardiomyopathy (HCM) is the most common monogenic cardiac disease with a highly variable phenotypic expression, ranging from asymptomatic to drug refractory heart failure (HF) presentation. Pharmacological therapy is the first line of treatment, but options are currently limited to nonspecific medication like betablockers or calcium channel inhibitors, with frequent suboptimal results. While being the gold standard practice for the management of drug refractory HCM patients, septal reduction therapy (SRT) remains an invasive procedure with associated surgical risks and it requires the expertise of the operating centre, thus limiting its accessibility. It is therefore with high interest that researchers look for pharmacological alternatives that could provide higher rates of success. With new data gathering these past years as well as the development of a new drug class showing promising results, this review provides an up-to-date focused synthesis of existing medical treatment options and future directions for HCM pharmacological treatment.
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Affiliation(s)
- Cristian Stătescu
- Cardiology Department, Cardiovascular Diseases Institute “Prof. Dr. George I.M. Georgescu”, Carol I Boulevard No. 50, 700503 Iași, Romania; (C.S.); (C.U.); (L.Ț.); (L.A.); (D.Ș.); (C.P.); (M.B.); (D.M.); (M.O.B.); (R.A.S.)
- Internal Medicine Department, “Grigore T. Popa” University of Medicine and Pharmacy, 700115 Iasi, Romania
| | - Ștefana Enachi
- Cardiology Department, Cardiovascular Diseases Institute “Prof. Dr. George I.M. Georgescu”, Carol I Boulevard No. 50, 700503 Iași, Romania; (C.S.); (C.U.); (L.Ț.); (L.A.); (D.Ș.); (C.P.); (M.B.); (D.M.); (M.O.B.); (R.A.S.)
- Correspondence: ; Tel.: +40-749-630-641
| | - Carina Ureche
- Cardiology Department, Cardiovascular Diseases Institute “Prof. Dr. George I.M. Georgescu”, Carol I Boulevard No. 50, 700503 Iași, Romania; (C.S.); (C.U.); (L.Ț.); (L.A.); (D.Ș.); (C.P.); (M.B.); (D.M.); (M.O.B.); (R.A.S.)
- Internal Medicine Department, “Grigore T. Popa” University of Medicine and Pharmacy, 700115 Iasi, Romania
| | - Laura Țăpoi
- Cardiology Department, Cardiovascular Diseases Institute “Prof. Dr. George I.M. Georgescu”, Carol I Boulevard No. 50, 700503 Iași, Romania; (C.S.); (C.U.); (L.Ț.); (L.A.); (D.Ș.); (C.P.); (M.B.); (D.M.); (M.O.B.); (R.A.S.)
| | - Larisa Anghel
- Cardiology Department, Cardiovascular Diseases Institute “Prof. Dr. George I.M. Georgescu”, Carol I Boulevard No. 50, 700503 Iași, Romania; (C.S.); (C.U.); (L.Ț.); (L.A.); (D.Ș.); (C.P.); (M.B.); (D.M.); (M.O.B.); (R.A.S.)
- Internal Medicine Department, “Grigore T. Popa” University of Medicine and Pharmacy, 700115 Iasi, Romania
| | - Delia Șalaru
- Cardiology Department, Cardiovascular Diseases Institute “Prof. Dr. George I.M. Georgescu”, Carol I Boulevard No. 50, 700503 Iași, Romania; (C.S.); (C.U.); (L.Ț.); (L.A.); (D.Ș.); (C.P.); (M.B.); (D.M.); (M.O.B.); (R.A.S.)
- Internal Medicine Department, “Grigore T. Popa” University of Medicine and Pharmacy, 700115 Iasi, Romania
| | - Carmen Pleșoianu
- Cardiology Department, Cardiovascular Diseases Institute “Prof. Dr. George I.M. Georgescu”, Carol I Boulevard No. 50, 700503 Iași, Romania; (C.S.); (C.U.); (L.Ț.); (L.A.); (D.Ș.); (C.P.); (M.B.); (D.M.); (M.O.B.); (R.A.S.)
- Internal Medicine Department, “Grigore T. Popa” University of Medicine and Pharmacy, 700115 Iasi, Romania
| | - Mădălina Bostan
- Cardiology Department, Cardiovascular Diseases Institute “Prof. Dr. George I.M. Georgescu”, Carol I Boulevard No. 50, 700503 Iași, Romania; (C.S.); (C.U.); (L.Ț.); (L.A.); (D.Ș.); (C.P.); (M.B.); (D.M.); (M.O.B.); (R.A.S.)
- Internal Medicine Department, “Grigore T. Popa” University of Medicine and Pharmacy, 700115 Iasi, Romania
| | - Dragoș Marcu
- Cardiology Department, Cardiovascular Diseases Institute “Prof. Dr. George I.M. Georgescu”, Carol I Boulevard No. 50, 700503 Iași, Romania; (C.S.); (C.U.); (L.Ț.); (L.A.); (D.Ș.); (C.P.); (M.B.); (D.M.); (M.O.B.); (R.A.S.)
- Internal Medicine Department, “Grigore T. Popa” University of Medicine and Pharmacy, 700115 Iasi, Romania
| | - Mircea Ovanez Balasanian
- Cardiology Department, Cardiovascular Diseases Institute “Prof. Dr. George I.M. Georgescu”, Carol I Boulevard No. 50, 700503 Iași, Romania; (C.S.); (C.U.); (L.Ț.); (L.A.); (D.Ș.); (C.P.); (M.B.); (D.M.); (M.O.B.); (R.A.S.)
- Internal Medicine Department, “Grigore T. Popa” University of Medicine and Pharmacy, 700115 Iasi, Romania
| | - Radu Andy Sascău
- Cardiology Department, Cardiovascular Diseases Institute “Prof. Dr. George I.M. Georgescu”, Carol I Boulevard No. 50, 700503 Iași, Romania; (C.S.); (C.U.); (L.Ț.); (L.A.); (D.Ș.); (C.P.); (M.B.); (D.M.); (M.O.B.); (R.A.S.)
- Internal Medicine Department, “Grigore T. Popa” University of Medicine and Pharmacy, 700115 Iasi, Romania
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Goldspink PH, Warren CM, Kitajewski J, Wolska BM, Solaro RJ. A Perspective on Personalized Therapies in Hypertrophic Cardiomyopathy. J Cardiovasc Pharmacol 2021; 77:317-322. [PMID: 33298734 PMCID: PMC7933064 DOI: 10.1097/fjc.0000000000000968] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/23/2020] [Accepted: 11/23/2020] [Indexed: 12/13/2022]
Abstract
ABSTRACT A dominant mechanism of sudden cardiac death in the young is the progression of maladaptive responses to genes encoding proteins linked to hypertrophic cardiomyopathy. Most are mutant sarcomere proteins that trigger the progression by imposing a biophysical defect on the dynamics and levels of myofilament tension generation. We discuss approaches for personalized treatments that are indicated by recent advanced understanding of the progression.
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Affiliation(s)
- Paul H. Goldspink
- Department of Physiology and Biophysics and Center for Cardiovascular Research, University of Illinois at Chicago, College of Medicine, Chicago, IL 60612
| | - Chad M. Warren
- Department of Physiology and Biophysics and Center for Cardiovascular Research, University of Illinois at Chicago, College of Medicine, Chicago, IL 60612
| | - Jan Kitajewski
- Department of Physiology and Biophysics and Center for Cardiovascular Research, University of Illinois at Chicago, College of Medicine, Chicago, IL 60612
| | - Beata M. Wolska
- Department of Physiology and Biophysics and Center for Cardiovascular Research, University of Illinois at Chicago, College of Medicine, Chicago, IL 60612
- Department of Medicine, Division of Cardiology, University of Illinois at Chicago, College of Medicine, Chicago, IL 60612
| | - R. John Solaro
- Department of Physiology and Biophysics and Center for Cardiovascular Research, University of Illinois at Chicago, College of Medicine, Chicago, IL 60612
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Parijat P, Kondacs L, Alexandrovich A, Gautel M, Cobb AJA, Kampourakis T. High Throughput Screen Identifies Small Molecule Effectors That Modulate Thin Filament Activation in Cardiac Muscle. ACS Chem Biol 2021; 16:225-235. [PMID: 33315370 DOI: 10.1021/acschembio.0c00908] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Current therapeutic interventions for both heart disease and heart failure are largely insufficient and associated with undesired side effects. Biomedical research has emphasized the role of sarcomeric protein function for the normal performance and energy efficiency of the heart, suggesting that directly targeting the contractile myofilaments themselves using small molecule effectors has therapeutic potential and will likely result in greater drug efficacy and selectivity. In this study, we developed a robust and highly reproducible fluorescence polarization-based high throughput screening (HTS) assay that directly targets the calcium-dependent interaction between cardiac troponin C (cTnC) and the switch region of cardiac troponin I (cTnISP), with the aim of identifying small molecule effectors of the cardiac thin filament activation pathway. We screened a commercially available small molecule library and identified several hit compounds with both inhibitory and activating effects. We used a range of biophysical and biochemical methods to characterize hit compounds and identified fingolimod, a sphingosin-1-phosphate receptor modulator, as a new troponin-based small molecule effector. Fingolimod decreased the ATPase activity and calcium sensitivity of demembranated cardiac muscle fibers in a dose-dependent manner, suggesting that the compound acts as a calcium desensitizer. We investigated fingolimod's mechanism of action using a combination of computational studies, biophysical methods, and synthetic chemistry, showing that fingolimod bound to cTnC repels cTnISP via mainly electrostatic repulsion of its positively charged tail. These results suggest that fingolimod is a potential new lead compound/scaffold for the development of troponin-directed heart failure therapeutics.
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Affiliation(s)
- Priyanka Parijat
- Randall Centre for Cell and Molecular Biophysics, King’s College London, and British Heart Foundation Centre of Research Excellence, London SE1 1UL, United Kingdom
| | - Laszlo Kondacs
- Department of Chemistry, King’s College London, 7 Trinity Street, London, SE1 1DB, United Kingdom
| | - Alexander Alexandrovich
- Randall Centre for Cell and Molecular Biophysics, King’s College London, and British Heart Foundation Centre of Research Excellence, London SE1 1UL, United Kingdom
| | - Mathias Gautel
- Randall Centre for Cell and Molecular Biophysics, King’s College London, and British Heart Foundation Centre of Research Excellence, London SE1 1UL, United Kingdom
| | - Alexander J. A. Cobb
- Department of Chemistry, King’s College London, 7 Trinity Street, London, SE1 1DB, United Kingdom
| | - Thomas Kampourakis
- Randall Centre for Cell and Molecular Biophysics, King’s College London, and British Heart Foundation Centre of Research Excellence, London SE1 1UL, United Kingdom
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17
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Warren CM, Halas M, Feng HZ, Wolska BM, Jin JP, Solaro RJ. NH 2-Terminal Cleavage of Cardiac Troponin I Signals Adaptive Response to Cardiac Stressors. JOURNAL OF CELLULAR SIGNALING 2021; 2:162-171. [PMID: 34541579 PMCID: PMC8444995] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 10/29/2022]
Abstract
Cardiac sarcomeres express a variant of troponin I (cTnI) that contains a unique N-terminal extension of ~30 amino acids with regulatory phosphorylation sites. The extension is important in the control of myofilament response to Ca2+, which contributes to the neuro-humoral regulation of the dynamics of cardiac contraction and relaxation. Hearts of various species including humans express a stress-induced truncated variant of cardiac troponin I (cTnI-ND) missing the first ~30 amino acids and functionally mimicking the phosphorylated state of cTnI. Studies have demonstrated that upregulation of cTnI-ND potentially represents a homeostatic mechanism as well as an adaptive response in pathophysiology including ischemia/reperfusion injury, beta adrenergic maladaptive activation, and aging. We present evidence showing that cTnI-ND can modify the trigger for hypertrophic cardiomyopathy (HCM) by reducing the Ca2+ sensitivity of myofilaments from hearts with an E180G mutation in α-tropomyosin. Induction of this truncation may represent a therapeutic approach to modifying Ca2+-responses in hearts with hypercontractility or heat failure with preserved ejection fraction.
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Affiliation(s)
- Chad M. Warren
- Department of Physiology & Biophysics, Center for Cardiovascular Research, University of Illinois at Chicago, USA
| | - Monika Halas
- Department of Physiology & Biophysics, Center for Cardiovascular Research, University of Illinois at Chicago, USA
| | - Han-Zhong Feng
- Department of Physiology & Biophysics, Center for Cardiovascular Research, University of Illinois at Chicago, USA
| | - Beata M. Wolska
- Department of Physiology & Biophysics, Center for Cardiovascular Research, University of Illinois at Chicago, USA,Division of Cardiology, Center for Cardiovascular Research, University of Illinois at Chicago, USA
| | - Jian-Ping Jin
- Department of Physiology & Biophysics, Center for Cardiovascular Research, University of Illinois at Chicago, USA
| | - R. John Solaro
- Department of Physiology & Biophysics, Center for Cardiovascular Research, University of Illinois at Chicago, USA,Correspondence should be addressed to R. John Solaro;
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18
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Holmes JB, Doh CY, Mamidi R, Li J, Stelzer JE. Strategies for targeting the cardiac sarcomere: avenues for novel drug discovery. Expert Opin Drug Discov 2020; 15:457-469. [PMID: 32067508 PMCID: PMC7065952 DOI: 10.1080/17460441.2020.1722637] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Accepted: 01/24/2020] [Indexed: 01/10/2023]
Abstract
Introduction: Heart failure remains one of the largest clinical challenges in the United States. Researchers have continually searched for more effective heart failure treatments that target the cardiac sarcomere but have found few successes despite numerous expensive cardiovascular clinical trials. Among many reasons, the high failure rate of cardiovascular clinical trials may be partly due to incomplete characterization of a drug candidate's complex interaction with cardiac physiology.Areas covered: In this review, the authors address the issue of preclinical cardiovascular studies of sarcomere-targeting heart failure therapies. The authors consider inherent tradeoffs made between mechanistic transparency and physiological fidelity for several relevant preclinical techniques at the atomic, molecular, heart muscle fiber, whole heart, and whole-organism levels. Thus, the authors suggest a comprehensive, bottom-up approach to preclinical cardiovascular studies that fosters scientific rigor and hypothesis-driven drug discovery.Expert opinion: In the authors' opinion, the implementation of hypothesis-driven drug discovery practices, such as the bottom-up approach to preclinical cardiovascular studies, will be imperative for the successful development of novel heart failure treatments. However, additional changes to clinical definitions of heart failure and current drug discovery culture must accompany the bottom-up approach to maximize the effectiveness of hypothesis-driven drug discovery.
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Affiliation(s)
- Joshua B Holmes
- Department of Physiology and Biophysics, School of Medicine, Case Western Reserve University, Cleveland, OH, USA
| | - Chang Yoon Doh
- Department of Physiology and Biophysics, School of Medicine, Case Western Reserve University, Cleveland, OH, USA
| | - Ranganath Mamidi
- Department of Physiology and Biophysics, School of Medicine, Case Western Reserve University, Cleveland, OH, USA
| | - Jiayang Li
- Department of Physiology and Biophysics, School of Medicine, Case Western Reserve University, Cleveland, OH, USA
| | - Julian E Stelzer
- Department of Physiology and Biophysics, School of Medicine, Case Western Reserve University, Cleveland, OH, USA
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Chowdhury SAK, Warren CM, Simon JN, Ryba DM, Batra A, Varga P, Kranias EG, Tardiff JC, Solaro RJ, Wolska BM. Modifications of Sarcoplasmic Reticulum Function Prevent Progression of Sarcomere-Linked Hypertrophic Cardiomyopathy Despite a Persistent Increase in Myofilament Calcium Response. Front Physiol 2020; 11:107. [PMID: 32210830 PMCID: PMC7075858 DOI: 10.3389/fphys.2020.00107] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Accepted: 01/30/2020] [Indexed: 01/12/2023] Open
Abstract
Hypertrophic cardiomyopathy (HCM) is a genetic disorder caused by mutations in different genes mainly encoding myofilament proteins and therefore called a “disease of the sarcomere.” Despite the discovery of sarcomere protein mutations linked to HCM almost 30 years ago, the cellular mechanisms responsible for the development of this disease are not completely understood and likely vary among different mutations. Moreover, despite many efforts to develop effective treatments for HCM, these have largely been unsuccessful, and more studies are needed to better understand the cellular mechanisms of the disease. In experiments reported here, we investigated a mouse model expressing the mutant cTnT-R92Q, which is linked to HCM and induces an increase in myofilament Ca2+ sensitivity and diastolic dysfunction. We found that early correction of the diastolic dysfunction by phospholamban knockout (PLNKO) was able to prevent the development of the HCM phenotype in troponin T (TnT)-R92Q transgenic (TG) mice. Four groups of mice in FVB/N background were generated and used for the experiments: (1) non-transgenic (NTG)/PLN mice, which express wild-type TnT and normal level of PLN; (2) NTG/PLNKO mice, which express wild-type TnT and no PLN; (3) TG/PLN mice, which express TnT-R92Q and normal level of PLN; (4) TG/PLNKO mice, which express TnT-R92Q and no PLN. Cardiac function was determined using both standard echocardiographic parameters and speckle tracking strain measurements. We found that both atrial morphology and diastolic function were altered in TG/PLN mice but normal in TG/PLNKO mice. Histological analysis showed a disarray of myocytes and increased collagen deposition only in TG/PLN hearts. We also observed increased Ca2+/calmodulin-dependent protein kinase II (CaMKII) phosphorylation only in TG/PLN hearts but not in TG/PLNKO hearts. The rescue of the HCM phenotype was not associated with differences in myofilament Ca2+ sensitivity between TG/PLN and TG/PLNKO mice. Moreover, compared to standard systolic echo parameters, such as ejection fraction (EF), speckle strain measurements provided a more sensitive approach to detect early systolic dysfunction in TG/PLN mice. In summary, our results indicate that targeting diastolic dysfunction through altering Ca2+ fluxes with no change in myofilament response to Ca2+ was able to prevent the development of the HCM phenotype and should be considered as a potential additional treatment for HCM patients.
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Affiliation(s)
- Shamim A K Chowdhury
- Department of Physiology and Biophysics and the Center for Cardiovascular Research, College of Medicine, University of Illinois at Chicago, Chicago, IL, United States
| | - Chad M Warren
- Department of Physiology and Biophysics and the Center for Cardiovascular Research, College of Medicine, University of Illinois at Chicago, Chicago, IL, United States
| | - Jillian N Simon
- Department of Physiology and Biophysics and the Center for Cardiovascular Research, College of Medicine, University of Illinois at Chicago, Chicago, IL, United States
| | - David M Ryba
- Department of Physiology and Biophysics and the Center for Cardiovascular Research, College of Medicine, University of Illinois at Chicago, Chicago, IL, United States
| | - Ashley Batra
- Department of Physiology and Biophysics and the Center for Cardiovascular Research, College of Medicine, University of Illinois at Chicago, Chicago, IL, United States
| | - Peter Varga
- Department of Pediatrics, Section of Cardiology, University of Illinois at Chicago, Chicago, IL, United States
| | - Evangelia G Kranias
- Department of Pharmacology and Systems Physiology, University of Cincinnati, Cincinnati, OH, United States
| | - Jil C Tardiff
- Department of Medicine, Division of Cardiology, The University of Arizona, Tucson, AZ, United States
| | - R John Solaro
- Department of Physiology and Biophysics and the Center for Cardiovascular Research, College of Medicine, University of Illinois at Chicago, Chicago, IL, United States
| | - Beata M Wolska
- Department of Physiology and Biophysics and the Center for Cardiovascular Research, College of Medicine, University of Illinois at Chicago, Chicago, IL, United States.,Department of Medicine, Division of Cardiology, University of Illinois at Chicago, Chicago, IL, United States
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20
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Landim-Vieira M, Johnston JR, Ji W, Mis EK, Tijerino J, Spencer-Manzon M, Jeffries L, Hall EK, Panisello-Manterola D, Khokha MK, Deniz E, Chase PB, Lakhani SA, Pinto JR. Familial Dilated Cardiomyopathy Associated With a Novel Combination of Compound Heterozygous TNNC1 Variants. Front Physiol 2020; 10:1612. [PMID: 32038292 PMCID: PMC6990120 DOI: 10.3389/fphys.2019.01612] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Accepted: 12/23/2019] [Indexed: 12/11/2022] Open
Abstract
Familial dilated cardiomyopathy (DCM), clinically characterized by enlargement and dysfunction of one or both ventricles of the heart, can be caused by variants in sarcomeric genes including TNNC1 (encoding cardiac troponin C, cTnC). Here, we report the case of two siblings with severe, early onset DCM who were found to have compound heterozygous variants in TNNC1: p.Asp145Glu (D145E) and p.Asp132Asn (D132N), which were inherited from the parents. We began our investigation with CRISPR/Cas9 knockout of TNNC1 in Xenopus tropicalis, which resulted in a cardiac phenotype in tadpoles consistent with DCM. Despite multiple maneuvers, we were unable to rescue the tadpole hearts with either human cTnC wild-type or patient variants to investigate the cardiomyopathy phenotype in vivo. We therefore utilized porcine permeabilized cardiac muscle preparations (CMPs) reconstituted with either wild-type or patient variant forms of cTnC to examine effects of the patient variants on contractile function. Incorporation of 50% WT/50% D145E into CMPs increased Ca2+ sensitivity of isometric force, consistent with prior studies. In contrast, incorporation of 50% WT/50% D132N, which had not been previously reported, decreased Ca2+ sensitivity of isometric force. CMPs reconstituted 50–50% with both variants mirrored WT in regard to myofilament Ca2+ responsiveness. Sinusoidal stiffness (SS) (0.2% peak-to-peak) and the kinetics of tension redevelopment (kTR) at saturating Ca2+ were similar to WT for all preparations. Modeling of Ca2+-dependence of kTR support the observation from Ca2+ responsiveness of steady-state isometric force, that the effects on each mutant (50% WT/50% mutant) were greater than the combination of the two mutants (50% D132N/50% D145E). Further studies are needed to ascertain the mechanism(s) of these variants.
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Affiliation(s)
- Maicon Landim-Vieira
- Department of Biomedical Sciences, College of Medicine, Florida State University, Tallahassee, FL, United States
| | - Jamie R Johnston
- Department of Biomedical Sciences, College of Medicine, Florida State University, Tallahassee, FL, United States
| | - Weizhen Ji
- Pediatric Genomics Discovery Program, Department of Pediatrics, Yale School of Medicine, Yale University, New Haven, CT, United States
| | - Emily K Mis
- Pediatric Genomics Discovery Program, Department of Pediatrics, Yale School of Medicine, Yale University, New Haven, CT, United States
| | - Joshua Tijerino
- Department of Biomedical Sciences, College of Medicine, Florida State University, Tallahassee, FL, United States
| | - Michele Spencer-Manzon
- Pediatric Genomics Discovery Program, Department of Pediatrics, Yale School of Medicine, Yale University, New Haven, CT, United States.,Department of Genetics, Yale School of Medicine, Yale University, New Haven, CT, United States
| | - Lauren Jeffries
- Pediatric Genomics Discovery Program, Department of Pediatrics, Yale School of Medicine, Yale University, New Haven, CT, United States
| | - E Kevin Hall
- Department of Pediatrics, Yale School of Medicine, Yale University, New Haven, CT, United States
| | - David Panisello-Manterola
- Pediatric Genomics Discovery Program, Department of Pediatrics, Yale School of Medicine, Yale University, New Haven, CT, United States
| | - Mustafa K Khokha
- Pediatric Genomics Discovery Program, Department of Pediatrics, Yale School of Medicine, Yale University, New Haven, CT, United States.,Department of Genetics, Yale School of Medicine, Yale University, New Haven, CT, United States
| | - Engin Deniz
- Pediatric Genomics Discovery Program, Department of Pediatrics, Yale School of Medicine, Yale University, New Haven, CT, United States
| | - P Bryant Chase
- Department of Biological Science, Florida State University, Tallahassee, FL, United States
| | - Saquib A Lakhani
- Pediatric Genomics Discovery Program, Department of Pediatrics, Yale School of Medicine, Yale University, New Haven, CT, United States
| | - Jose Renato Pinto
- Department of Biomedical Sciences, College of Medicine, Florida State University, Tallahassee, FL, United States
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21
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Wijnker PJM, Sequeira V, Kuster DWD, Velden JVD. Hypertrophic Cardiomyopathy: A Vicious Cycle Triggered by Sarcomere Mutations and Secondary Disease Hits. Antioxid Redox Signal 2019; 31:318-358. [PMID: 29490477 PMCID: PMC6602117 DOI: 10.1089/ars.2017.7236] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Significance: Hypertrophic cardiomyopathy (HCM) is a cardiac genetic disease characterized by left ventricular hypertrophy, diastolic dysfunction, and myocardial disarray. Disease onset occurs between 20 and 50 years of age, thus affecting patients in the prime of their life. HCM is caused by mutations in sarcomere proteins, the contractile building blocks of the heart. Despite increased knowledge of causal mutations, the exact path from genetic defect leading to cardiomyopathy is complex and involves additional disease hits. Recent Advances: Laboratory-based studies indicate that HCM development not only depends on the primary sarcomere impairment caused by the mutation but also on secondary disease-related alterations in the heart. Here we propose a vicious mutation-induced disease cycle, in which a mutation-induced energy depletion alters cellular metabolism with increased mitochondrial work, which triggers secondary disease modifiers that will worsen disease and ultimately lead to end-stage HCM. Critical Issues: Evidence shows excessive cellular reactive oxygen species (ROS) in HCM patients and HCM animal models. Oxidative stress markers are increased in the heart (oxidized proteins, DNA, and lipids) and serum of HCM patients. In addition, increased mitochondrial ROS production and changes in endogenous antioxidants are reported in HCM. Mutant sarcomeric protein may drive excessive levels of cardiac ROS via changes in cardiac efficiency and metabolism, mitochondrial activation and/or dysfunction, impaired protein quality control, and microvascular dysfunction. Future Directions: Interventions restoring metabolism, mitochondrial function, and improved ROS balance may be promising therapeutic approaches. We discuss the effects of current HCM pharmacological therapies and potential future therapies to prevent and reverse HCM. Antioxid. Redox Signal. 31, 318-358.
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Affiliation(s)
- Paul J M Wijnker
- 1 Department of Physiology, Amsterdam Cardiovascular Sciences, VU University Medical Center, Amsterdam, The Netherlands
| | - Vasco Sequeira
- 1 Department of Physiology, Amsterdam Cardiovascular Sciences, VU University Medical Center, Amsterdam, The Netherlands
| | - Diederik W D Kuster
- 1 Department of Physiology, Amsterdam Cardiovascular Sciences, VU University Medical Center, Amsterdam, The Netherlands
| | - Jolanda van der Velden
- 1 Department of Physiology, Amsterdam Cardiovascular Sciences, VU University Medical Center, Amsterdam, The Netherlands.,2 Netherlands Heart Institute, Utrecht, The Netherlands
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22
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Sarcomeric mutations in cardiac diseases. Pflugers Arch 2019; 471:659-660. [PMID: 30976925 DOI: 10.1007/s00424-019-02275-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Accepted: 04/01/2019] [Indexed: 10/27/2022]
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23
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Kresin N, Stücker S, Krämer E, Flenner F, Mearini G, Münch J, Patten M, Redwood C, Carrier L, Friedrich FW. Analysis of Contractile Function of Permeabilized Human Hypertrophic Cardiomyopathy Multicellular Heart Tissue. Front Physiol 2019; 10:239. [PMID: 30984009 PMCID: PMC6447666 DOI: 10.3389/fphys.2019.00239] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2018] [Accepted: 02/22/2019] [Indexed: 01/08/2023] Open
Affiliation(s)
- Nico Kresin
- Institute of Experimental Pharmacology and Toxicology, Cardiovascular Research Center, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,DZHK (German Centre for Cardiovascular Research), Partner Site Hamburg/Kiel/Lübeck, Hamburg, Germany
| | - Sabrina Stücker
- Institute of Experimental Pharmacology and Toxicology, Cardiovascular Research Center, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,DZHK (German Centre for Cardiovascular Research), Partner Site Hamburg/Kiel/Lübeck, Hamburg, Germany
| | - Elisabeth Krämer
- Institute of Experimental Pharmacology and Toxicology, Cardiovascular Research Center, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,DZHK (German Centre for Cardiovascular Research), Partner Site Hamburg/Kiel/Lübeck, Hamburg, Germany
| | - Frederik Flenner
- Institute of Experimental Pharmacology and Toxicology, Cardiovascular Research Center, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,DZHK (German Centre for Cardiovascular Research), Partner Site Hamburg/Kiel/Lübeck, Hamburg, Germany
| | - Giulia Mearini
- Institute of Experimental Pharmacology and Toxicology, Cardiovascular Research Center, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,DZHK (German Centre for Cardiovascular Research), Partner Site Hamburg/Kiel/Lübeck, Hamburg, Germany
| | - Julia Münch
- University Heart Center Hamburg, Hamburg, Germany
| | | | - Charles Redwood
- Radcliffe Department of Medicine, University of Oxford, John Radcliffe Hospital, Oxford, United Kingdom
| | - Lucie Carrier
- Institute of Experimental Pharmacology and Toxicology, Cardiovascular Research Center, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,DZHK (German Centre for Cardiovascular Research), Partner Site Hamburg/Kiel/Lübeck, Hamburg, Germany
| | - Felix W Friedrich
- Institute of Experimental Pharmacology and Toxicology, Cardiovascular Research Center, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,DZHK (German Centre for Cardiovascular Research), Partner Site Hamburg/Kiel/Lübeck, Hamburg, Germany
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24
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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.
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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.
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25
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Dieseldorff Jones KM, Koh Y, Weller RS, Turna RS, Ahmad F, Huke S, Knollmann BC, Pinto JR, Hwang HS. Pathogenic troponin T mutants with opposing effects on myofilament Ca 2+ sensitivity attenuate cardiomyopathy phenotypes in mice. Arch Biochem Biophys 2018; 661:125-131. [PMID: 30445044 DOI: 10.1016/j.abb.2018.11.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2018] [Revised: 08/28/2018] [Accepted: 11/08/2018] [Indexed: 01/14/2023]
Abstract
Mutations in cardiac troponin T (TnT) associated with hypertrophic cardiomyopathy generally lead to an increase in the Ca2+ sensitivity of contraction and susceptibility to arrhythmias. In contrast, TnT mutations linked to dilated cardiomyopathy decrease the Ca2+ sensitivity of contraction. Here we tested the hypothesis that two TnT disease mutations with opposite effects on myofilament Ca2+ sensitivity can attenuate each other's phenotype. We crossed transgenic mice expressing the HCM TnT-I79N mutation (I79N) with a DCM knock-in mouse model carrying the heterozygous TnT-R141W mutation (HET). The results of the Ca2+ sensitivity in skinned cardiac muscle preparations ranked from highest to lowest were as follow: I79N > I79N/HET > NTg > HET. Echocardiographic measurements revealed an improvement in hemodynamic parameters in I79N/HET compared to I79N and normalization of left ventricular dimensions and volumes compared to both I79N and HET. Ex vivo testing showed that the I79N/HET mouse hearts had reduced arrhythmia susceptibility compared to I79N mice. These results suggest that two disease mutations in TnT that have opposite effects on the myofilament Ca2+ sensitivity can paradoxically ameliorate each other's disease phenotype. Normalizing myofilament Ca2+ sensitivity may be a promising new treatment approach for a variety of diseases.
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Affiliation(s)
| | - Yeojung Koh
- Department of Nutrition, Food and Exercise Sciences, Florida State University, Tallahassee, FL, USA
| | - Rebecca S Weller
- Division of Clinical Pharmacology, Vanderbilt University, Nashville, TN, USA
| | - Rajdeep S Turna
- Biomedical Sciences, Florida State University, Tallahassee, FL, USA
| | - Ferhaan Ahmad
- Department of Internal Medicine University of Iowa, Iowa City, IA, USA
| | - Sabine Huke
- Division of Clinical Pharmacology, Vanderbilt University, Nashville, TN, USA; Department of Medicine, Division of Cardiovascular Disease, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Björn C Knollmann
- Division of Clinical Pharmacology, Vanderbilt University, Nashville, TN, USA
| | | | - Hyun Seok Hwang
- Department of Nutrition, Food and Exercise Sciences, Florida State University, Tallahassee, FL, USA.
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26
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Coronary arterial vasculature in the pathophysiology of hypertrophic cardiomyopathy. Pflugers Arch 2018; 471:769-780. [PMID: 30370501 DOI: 10.1007/s00424-018-2224-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2018] [Accepted: 10/16/2018] [Indexed: 02/07/2023]
Abstract
Alterations in the coronary vascular system are likely associated with a mismatch between energy demand and energy supply and critical in triggering the cascade of events that leads to symptomatic hypertrophic cardiomyopathy. Targeting the early events, particularly vascular remodeling, may be a key approach to developing effective treatments. Improvement in our understanding of hypertrophic cardiomyopathy began with the results of early biophysical studies, proceeded to genetic analyses pinpointing the mutational origin, and now pertains to imaging of the metabolic and flow-related consequences of such mutations. Microvascular dysfunction has been an ongoing hot topic in the imaging of genetic cardiomyopathies marked by its histologically significant remodeling and has proven to be a powerful asset in determining prognosis for these patients as well as enlightening scientists on a potential pathophysiological cascade that may begin early during the developmental process. Here, we discuss questions that continue to remain on the mechanistic processes leading to microvascular dysfunction, its correlation to the morphological changes in the vessels, and its contribution to disease progression.
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27
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Dvornikov AV, de Tombe PP, Xu X. Phenotyping cardiomyopathy in adult zebrafish. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2018; 138:116-125. [PMID: 29884423 PMCID: PMC6269218 DOI: 10.1016/j.pbiomolbio.2018.05.013] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2018] [Revised: 04/26/2018] [Accepted: 05/29/2018] [Indexed: 12/21/2022]
Abstract
Hypertrophic cardiomyopathy (HCM) is usually manifested by increased myofilament Ca2+ sensitivity, excessive contractility, and impaired relaxation. In contrast, dilated cardiomyopathy (DCM) originates from insufficient sarcomere contractility and reduced cardiac pump function, subsequently resulting in heart failure. The zebrafish has emerged as a new model of human cardiomyopathy with high-throughput screening, which will facilitate the discovery of novel genetic factors and the development of new therapies. Given the small hearts of zebrafish, better phenotyping tools are needed to discern different types of cardiomyopathy, such as HCM and DCM. This article reviews the existing models of cardiomyopathy, available morphologic and functional methods, and current understanding of the different types of cardiomyopathy in adult zebrafish.
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Affiliation(s)
- Alexey V Dvornikov
- Department of Biochemistry and Molecular Biology, Department of Cardiovascular Medicine, Mayo Clinic, Rochester, MN, USA.
| | - Pieter P de Tombe
- University of Illinois at Chicago, Department of Physiology and Biophysics, Chicago, IL, USA; Magdi Yacoub Institute, Cardiac Biophysics Division, Harefield, UK; Imperial College, Heart and Lung Institute, London, UK; Freiburg University, Institute for Experimental Cardiovascular Medicine, Germany
| | - Xiaolei Xu
- Department of Biochemistry and Molecular Biology, Department of Cardiovascular Medicine, Mayo Clinic, Rochester, MN, USA.
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28
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Monasky MM, Pappone C, Piccoli M, Ghiroldi A, Micaglio E, Anastasia L. Calcium in Brugada Syndrome: Questions for Future Research. Front Physiol 2018; 9:1088. [PMID: 30147658 PMCID: PMC6095984 DOI: 10.3389/fphys.2018.01088] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Accepted: 07/23/2018] [Indexed: 12/11/2022] Open
Abstract
The Brugada syndrome (BrS) is characterized by coved-type ST-segment elevation in the right precordial leads on the electrocardiogram (ECG) and increased risk of sudden cardiac death (SCD). While it is an inheritable disease, determining the true prevalence is a challenge, since patients may report no known family history of the syndrome, present with a normal spontaneous ECG pattern at the time of examination, and test negative for all known BrS-causative genes. In fact, SCD is often the first indication that a person is affected by the syndrome. Men are more likely to be symptomatic than women. Abnormal, low-voltage, fractionated electrograms have been found in the epicardium of the right ventricular outflow tract (RVOT). Ablation of this area abolishes the abnormal electrograms and helps to prevent arrhythmic recurrences. BrS patients are more likely to experience ventricular tachycardia/fibrillation (VT/VF) during fever or during an increase in vagal tone. Isoproterenol helps to reverse the ECG BrS phenotype. In this review, we discuss roles of calcium in various conditions that are relevant to BrS, such as changes in temperature, heart rate, and vagal tone, and the effects of gender and isoproterenol on calcium handling. Studies are warranted to further investigate these mechanisms in models of BrS.
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Affiliation(s)
| | - Carlo Pappone
- Arrhythmology Department, IRCCS Policlinico San Donato, Milan, Italy
| | - Marco Piccoli
- Stem Cells for Tissue Engineering Lab, IRCCS Policlinico San Donato, Milan, Italy
| | - Andrea Ghiroldi
- Stem Cells for Tissue Engineering Lab, IRCCS Policlinico San Donato, Milan, Italy
| | - Emanuele Micaglio
- Arrhythmology Department, IRCCS Policlinico San Donato, Milan, Italy
| | - Luigi Anastasia
- Stem Cells for Tissue Engineering Lab, IRCCS Policlinico San Donato, Milan, Italy.,Department of Biomedical Sciences for Health, University of Milan, Milan, Italy
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29
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Alves ML, Warren CM, Simon JN, Gaffin RD, Montminy EM, Wieczorek DF, Solaro RJ, Wolska BM. Early sensitization of myofilaments to Ca2+ prevents genetically linked dilated cardiomyopathy in mice. Cardiovasc Res 2018; 113:915-925. [PMID: 28379313 DOI: 10.1093/cvr/cvx068] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Accepted: 03/31/2017] [Indexed: 12/14/2022] Open
Abstract
Background Dilated cardiomoypathies (DCM) are a heterogeneous group of inherited and acquired diseases characterized by decreased contractility and enlargement of cardiac chambers and a major cause of morbidity and mortality. Mice with Glu54Lys mutation in α-tropomyosin (Tm54) demonstrate typical DCM phenotype with reduced myofilament Ca2+ sensitivity. We tested the hypothesis that early sensitization of the myofilaments to Ca2+ in DCM can prevent the DCM phenotype. Methods and results To sensitize Tm54 myofilaments, we used a genetic approach and crossbred Tm54 mice with mice expressing slow skeletal troponin I (ssTnI) that sensitizes myofilaments to Ca2+. Four groups of mice were used: non-transgenic (NTG), Tm54, ssTnI and Tm54/ssTnI (DTG). Systolic function was significantly reduced in the Tm54 mice compared to NTG, but restored in DTG mice. Tm54 mice also showed increased diastolic LV dimensions and HW/BW ratios, when compared to NTG, which were improved in the DTG group. β-myosin heavy chain expression was increased in the Tm54 animals compared to NTG and was partially restored in DTG group. Analysis by 2D-DIGE indicated a significant decrease in two phosphorylated spots of cardiac troponin I (cTnI) in the DTG animals compared to NTG and Tm54. Analysis by 2D-DIGE also indicated no significant changes in troponin T, regulatory light chain, myosin binding protein C and tropomyosin phosphorylation. Conclusion Our data indicate that decreased myofilament Ca2+ sensitivity is an essential element in the pathophysiology of thin filament linked DCM. Sensitization of myofilaments to Ca2+ in the early stage of DCM may be a useful therapeutic strategy in thin filament linked DCM.
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Affiliation(s)
- Marco L Alves
- Department of Physiology and Biophysics, Center for Cardiovascular Research, University of Illinois, 835 S Wolcott Ave. (M/C 901), Chicago, IL 60612, USA.,Center for Research in Echocardiography and Cardiology, Heart Institute, University of Sao Paulo, Avenida Dr. Eneas de Carvalho Aguiar 44, 05403-900, Sao Paulo, Brazil
| | - Chad M Warren
- Department of Physiology and Biophysics, Center for Cardiovascular Research, University of Illinois, 835 S Wolcott Ave. (M/C 901), Chicago, IL 60612, USA
| | - Jillian N Simon
- Department of Physiology and Biophysics, Center for Cardiovascular Research, University of Illinois, 835 S Wolcott Ave. (M/C 901), Chicago, IL 60612, USA
| | - Robert D Gaffin
- Department of Physiology and Biophysics, Center for Cardiovascular Research, University of Illinois, 835 S Wolcott Ave. (M/C 901), Chicago, IL 60612, USA
| | - Eric M Montminy
- Department of Physiology and Biophysics, Center for Cardiovascular Research, University of Illinois, 835 S Wolcott Ave. (M/C 901), Chicago, IL 60612, USA
| | - David F Wieczorek
- Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati, College of Medicine, 231 Albert Sabin Way, Cincinnati, OH 45267, USA
| | - R John Solaro
- Department of Physiology and Biophysics, Center for Cardiovascular Research, University of Illinois, 835 S Wolcott Ave. (M/C 901), Chicago, IL 60612, USA
| | - Beata M Wolska
- Department of Physiology and Biophysics, Center for Cardiovascular Research, University of Illinois, 835 S Wolcott Ave. (M/C 901), Chicago, IL 60612, USA.,Department of Medicine, Division of Cardiology, University of Illinois, 840 S Wood St. (M/C 715), Chicago, IL 60612, USA
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30
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Monasky MM, Ciconte G, Anastasia L, Pappone C. Commentary: Next Generation Sequencing and Linkage Analysis for the Molecular Diagnosis of a Novel Overlapping Syndrome Characterized by Hypertrophic Cardiomyopathy and Typical Electrical Instability of Brugada Syndrome. Front Physiol 2017; 8:1056. [PMID: 29311983 PMCID: PMC5733025 DOI: 10.3389/fphys.2017.01056] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Accepted: 12/04/2017] [Indexed: 11/13/2022] Open
Affiliation(s)
| | - Giuseppe Ciconte
- Arrhythmology Department, IRCCS Policlinico San Donato, Milan, Italy
| | - Luigi Anastasia
- Stem Cells for Tissue Engineering Lab, IRCCS Policlinico San Donato, Milan, Italy.,Department of Biomedical Sciences for Health, University of Milan, Milan, Italy
| | - Carlo Pappone
- Arrhythmology Department, IRCCS Policlinico San Donato, Milan, Italy
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Stücker S, Kresin N, Carrier L, Friedrich FW. Nebivolol Desensitizes Myofilaments of a Hypertrophic Cardiomyopathy Mouse Model. Front Physiol 2017; 8:558. [PMID: 28824454 PMCID: PMC5539082 DOI: 10.3389/fphys.2017.00558] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Accepted: 07/17/2017] [Indexed: 01/19/2023] Open
Abstract
Background: Hypertrophic cardiomyopathy (HCM) patients often present with diastolic dysfunction and a normal to supranormal systolic function. To counteract this hypercontractility, guideline therapies advocate treatment with beta-adrenoceptor and Ca2+ channel blockers. One well established pathomechanism for the hypercontractile phenotype frequently observed in HCM patients and several HCM mouse models is an increased myofilament Ca2+ sensitivity. Nebivolol, a commonly used beta-adrenoceptor antagonist, has been reported to lower maximal force development and myofilament Ca2+ sensitivity in rabbit and human heart tissues. The aim of this study was to evaluate the effect of nebivolol in cardiac muscle strips of an established HCM Mybpc3 mouse model. Furthermore, we investigated actions of nebivolol and epigallocatechin-gallate, which has been shown to desensitize myofilaments for Ca2+ in mouse and human HCM models, in cardiac strips of HCM patients with a mutation in the most frequently mutated HCM gene MYBPC3. Methods and Results: Nebivolol effects were tested on contractile parameters and force-Ca2+ relationship of skinned ventricular muscle strips isolated from Mybpc3-targeted knock-in (KI), wild-type (WT) mice and cardiac strips of three HCM patients with MYBPC3 mutations. At baseline, KI strips showed no difference in maximal force development compared to WT mouse heart strips. Neither 1 nor 10 μM nebivolol had an effect on maximal force development in both genotypes. 10 μM nebivolol induced myofilament Ca2+ desensitization in WT strips and to a greater extent in KI strips. Neither 1 nor 10 μM nebivolol had an effect on Ca2+ sensitivity in cardiac muscle strips of three HCM patients with MYBPC3 mutations, whereas epigallocatechin-gallate induced a right shift in the force-Ca2+ curve. Conclusion: Nebivolol induced a myofilament Ca2+ desensitization in both WT and KI strips, which was more pronounced in KI muscle strips. In human cardiac muscle strips of three HCM patients nebivolol had no effect on myofilament Ca2+ sensitivity.
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Affiliation(s)
- Sabrina Stücker
- Department of Experimental Pharmacology and Toxicology, Cardiovascular Research Center, University Medical Center Hamburg-EppendorfHamburg, Germany.,German Centre for Cardiovascular Research (DZHK)Hamburg, Germany
| | - Nico Kresin
- Department of Experimental Pharmacology and Toxicology, Cardiovascular Research Center, University Medical Center Hamburg-EppendorfHamburg, Germany.,German Centre for Cardiovascular Research (DZHK)Hamburg, Germany
| | - Lucie Carrier
- Department of Experimental Pharmacology and Toxicology, Cardiovascular Research Center, University Medical Center Hamburg-EppendorfHamburg, Germany.,German Centre for Cardiovascular Research (DZHK)Hamburg, Germany
| | - Felix W Friedrich
- Department of Experimental Pharmacology and Toxicology, Cardiovascular Research Center, University Medical Center Hamburg-EppendorfHamburg, Germany.,German Centre for Cardiovascular Research (DZHK)Hamburg, Germany
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32
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Silva FS, Bortolin RH, Araújo DN, Marques DE, Lima JPM, Rezende AA, Vieira WH, Silva NB, Medeiros KC, Ackermann PW, Abreu BJ, Dias FA. Exercise training ameliorates matrix metalloproteinases 2 and 9 messenger RNA expression and mitigates adverse left ventricular remodeling in streptozotocin-induced diabetic rats. Cardiovasc Pathol 2017; 29:37-44. [DOI: 10.1016/j.carpath.2017.05.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/19/2017] [Revised: 04/30/2017] [Accepted: 05/16/2017] [Indexed: 01/22/2023] Open
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Abstract
Cardiomyopathies represent a heterogeneous group of diseases that negatively affect heart function. Primary cardiomyopathies specifically target the myocardium, and may arise from genetic [hypertrophic cardiomyopathy (HCM), arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D), mitochondrial cardiomyopathy] or genetic and acquired [dilated cardiomyopathy (DCM), restrictive cardiomyopathy (RCM)] etiology. Modern genomics has identified mutations that are common in these populations, while in vitro and in vivo experimentation with these mutations have provided invaluable insight into the molecular mechanisms native to these diseases. For example, increased myosin heavy chain (MHC) binding and ATP utilization lead to the hypercontractile sarcomere in HCM, while abnormal protein–protein interaction and impaired Ca2+ flux underlie the relaxed sarcomere of DCM. Furthermore, expanded access to genetic testing has facilitated identification of potential risk factors that appear through inheritance and manifest sometimes only in the advanced stages of the disease. In this review, we discuss the genetic and molecular abnormalities unique to and shared between these primary cardiomyopathies and discuss some of the important advances made using more traditional basic science experimentation.
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Lorenz K, Rosner MR, Brand T, Schmitt JP. Raf kinase inhibitor protein: lessons of a better way for β-adrenergic receptor activation in the heart. J Physiol 2017; 595:4073-4087. [PMID: 28444807 PMCID: PMC5471367 DOI: 10.1113/jp274064] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2017] [Accepted: 02/27/2017] [Indexed: 12/13/2022] Open
Abstract
Stimulation of β-adrenergic receptors (βARs) provides the most efficient physiological mechanism to enhance contraction and relaxation of the heart. Activation of βARs allows rapid enhancement of myocardial function in order to fuel the muscles for running and fighting in a fight-or-flight response. Likewise, βARs become activated during cardiovascular disease in an attempt to counteract the restrictions of cardiac output. However, long-term stimulation of βARs increases the likelihood of cardiac arrhythmias, adverse ventricular remodelling, decline of cardiac performance and premature death, thereby limiting the use of βAR agonists in the treatment of heart failure. Recently the endogenous Raf kinase inhibitor protein (RKIP) was found to activate βAR signalling of the heart without adverse effects. This review will summarize the current knowledge on RKIP-driven compared to receptor-mediated signalling in cardiomyocytes. Emphasis is given to the differential effects of RKIP on β1 - and β2 -ARs and their downstream targets, the regulation of myocyte calcium cycling and myofilament activity.
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Affiliation(s)
- Kristina Lorenz
- Comprehensive Heart Failure CenterUniversity of WürzburgVersbacher Straße 997078WürzburgGermany
- West German Heart and Vascular Center EssenUniversity Hospital EssenHufelandstraße 5545147EssenGermany
- Leibniz‐Institut für Analytische Wissenschaften – ISAS – e.V.Bunsen‐Kirchhoff‐Straße 1144139DortmundGermany
- Institute of Pharmacology and ToxicologyUniversity of WürzburgVersbacher Straße 997078WürzburgGermany
| | - Marsha Rich Rosner
- Ben May Department for Cancer ResearchUniversity of ChicagoChicagoIL 60637USA
| | - Theresa Brand
- Leibniz‐Institut für Analytische Wissenschaften – ISAS – e.V.Bunsen‐Kirchhoff‐Straße 1144139DortmundGermany
- Institute of Pharmacology and ToxicologyUniversity of WürzburgVersbacher Straße 997078WürzburgGermany
| | - Joachim P Schmitt
- Institute of Pharmacology and Clinical PharmacologyDüsseldorf University HospitalUniverstitätsstraße 140225DüsseldorfGermany
- Cardiovascular Research Institute Düsseldorf (CARID)Heinrich‐Heine‐UniversityUniverstitätsstraße 140225DüsseldorfGermany
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Abstract
Striated cardiac and skeletal muscles play very different roles in the body, but they are similar at the molecular level. In particular, contraction, regardless of the type of muscle, is a precise and complex process involving the integral protein myofilaments and their associated regulatory components. The smallest functional unit of muscle contraction is the sarcomere. Within the sarcomere can be found a sophisticated ensemble of proteins associated with the thick filaments (myosin, myosin binding protein-C, titin, and obscurin) and thin myofilaments (actin, troponin, tropomyosin, nebulin, and nebulette). These parallel thick and thin filaments slide across one another, pulling the two ends of the sarcomere together to regulate contraction. More specifically, the regulation of both timing and force of contraction is accomplished through an intricate network of intra- and interfilament interactions belonging to each myofilament. This review introduces the sarcomere proteins involved in striated muscle contraction and places greater emphasis on the more recently identified and less well-characterized myofilaments: cardiac myosin binding protein-C, titin, nebulin, and obscurin. © 2017 American Physiological Society. Compr Physiol 7:675-692, 2017.
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Affiliation(s)
- Brian Leei Lin
- Department of Cell and Molecular Physiology, Health Sciences Division, Loyola University Chicago, Maywood, Illinois, USA
| | - Taejeong Song
- Department of Cell and Molecular Physiology, Health Sciences Division, Loyola University Chicago, Maywood, Illinois, USA.,Department of Internal Medicine, Heart, Lung and Vascular Institute, Division of Cardiovascular Health and Sciences, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
| | - Sakthivel Sadayappan
- Department of Cell and Molecular Physiology, Health Sciences Division, Loyola University Chicago, Maywood, Illinois, USA.,Department of Internal Medicine, Heart, Lung and Vascular Institute, Division of Cardiovascular Health and Sciences, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
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36
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Karam CN, Warren CM, Henze M, Banke NH, Lewandowski ED, Solaro RJ. Peroxisome proliferator-activated receptor-α expression induces alterations in cardiac myofilaments in a pressure-overload model of hypertrophy. Am J Physiol Heart Circ Physiol 2017; 312:H681-H690. [PMID: 28130336 DOI: 10.1152/ajpheart.00469.2016] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Revised: 01/04/2017] [Accepted: 01/17/2017] [Indexed: 01/22/2023]
Abstract
Although alterations in fatty acid (FA) metabolism have been shown to have a negative impact on contractility of the hypertrophied heart, the targets of action remain elusive. In this study we compared the function of skinned fiber bundles from transgenic (Tg) mice that overexpress a relatively low level of the peroxisome proliferator-activated receptor α (PPARα), and nontransgenic (NTg) littermates. The mice (NTg-T and Tg-T) were stressed by transverse aortic constriction (TAC) and compared with shams (NTg-S and Tg-S). There was an approximate 4-fold increase in PPARα expression in Tg-S compared with NTg-S, but Tg-T hearts showed the same PPARα expression as NTg-T. Expression of PPARα did not alter the hypertrophic response to TAC but did reduce ejection fraction (EF) in Tg-T hearts compared with other groups. The rate of actomyosin ATP hydrolysis was significantly higher in Tg-S skinned fiber bundles compared with all other groups. Tg-T hearts showed an increase in phosphorylation of specific sites on cardiac myosin binding protein-C (cMyBP-C) and β-myosin heavy chain isoform. These results advance our understanding of potential signaling to the myofilaments induced by altered FA metabolism under normal and pathological states. We demonstrate that chronic and transient PPARα activation during pathological stress alters myofilament response to Ca2+ through a mechanism that is possibly mediated by MyBP-C phosphorylation and myosin heavy chain isoforms.NEW & NOTEWORTHY Data presented here demonstrate novel signaling to sarcomeric proteins by chronic alterations in fatty acid metabolism induced by PPARα. The mechanism involves modifications of key myofilament regulatory proteins modifying cross-bridge dynamics with differential effects in controls and hearts stressed by pressure overload.
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Affiliation(s)
- Chehade N Karam
- Department of Physiology & Biophysics, Center for Cardiovascular Research, University of Illinois at Chicago, Chicago, Illinois; and
| | - Chad M Warren
- Department of Physiology & Biophysics, Center for Cardiovascular Research, University of Illinois at Chicago, Chicago, Illinois; and
| | - Marcus Henze
- Department of Physiology & Biophysics, Center for Cardiovascular Research, University of Illinois at Chicago, Chicago, Illinois; and
| | - Natasha H Banke
- Department of Physiology & Biophysics, Center for Cardiovascular Research, University of Illinois at Chicago, Chicago, Illinois; and
| | - E Douglas Lewandowski
- Department of Physiology & Biophysics, Center for Cardiovascular Research, University of Illinois at Chicago, Chicago, Illinois; and.,Sanford Burnham Presbyterian Medical Discovery Institute, Orlando, Florida
| | - R John Solaro
- Department of Physiology & Biophysics, Center for Cardiovascular Research, University of Illinois at Chicago, Chicago, Illinois; and
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37
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Liu X, Zhang L, Pacciulli D, Zhao J, Nan C, Shen W, Quan J, Tian J, Huang X. Restrictive Cardiomyopathy Caused by Troponin Mutations: Application of Disease Animal Models in Translational Studies. Front Physiol 2016; 7:629. [PMID: 28066262 PMCID: PMC5165243 DOI: 10.3389/fphys.2016.00629] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2016] [Accepted: 12/02/2016] [Indexed: 12/14/2022] Open
Abstract
Cardiac troponin I (cTnI) plays a critical role in regulation of cardiac function. Studies have shown that the deficiency of cTnI or mutations in cTnI (particularly in the C-terminus of cTnI) results in diastolic dysfunction (impaired relaxation) due to an increased myofibril sensitivity to calcium. The first clinical study revealing the association between restrictive cardiomyopathy (RCM) with cardiac troponin mutations was reported in 2003. In order to illustrate the mechanisms underlying the cTnI mutation caused cardiomyopathy, we have generated a cTnI gene knockout mouse model and transgenic mouse lines with the reported point mutations in cTnI C-terminus. In this paper, we summarize our studies using these animal models from our laboratory and the other in vitro studies using reconstituted filament and cultured cells. The potential mechanisms underlying diastolic dysfunction and heart failure caused by these cTnI C-terminal mutations are discussed as well. Furthermore, calcium desensitizing in correction of impaired relaxation in myocardial cells due to cTnI mutations is discussed. Finally, we describe a model of translational study, i.e., from bedside to bench and from bench to bedside. These studies may enrich our understanding of the mechanism underlying inherited cardiomyopathies and provide the clues to search for target-oriented medication aiming at the treatment of diastolic dysfunction and heart failure.
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Affiliation(s)
- Xiaoyan Liu
- Cardiovascular Research Laboratory, Division of Cardiology, Chongqing Medical University Children's Hospital Chongqing, China
| | - Lei Zhang
- Cardiovascular Research Laboratory, Division of Cardiology, Chongqing Medical University Children's Hospital Chongqing, China
| | - Daniel Pacciulli
- Department of Biomedical Science, Charles E. Schmidt College of Medicine, Florida Atlantic University Boca Raton, FL, USA
| | - Jianquan Zhao
- Department of Cardiology, Bayannaoer City Hospital Bayannaoer, China
| | - Changlong Nan
- Department of Biomedical Science, Charles E. Schmidt College of Medicine, Florida Atlantic University Boca Raton, FL, USA
| | - Wen Shen
- Department of Biomedical Science, Charles E. Schmidt College of Medicine, Florida Atlantic University Boca Raton, FL, USA
| | - Junjun Quan
- Cardiovascular Research Laboratory, Division of Cardiology, Chongqing Medical University Children's Hospital Chongqing, China
| | - Jie Tian
- Cardiovascular Research Laboratory, Division of Cardiology, Chongqing Medical University Children's Hospital Chongqing, China
| | - Xupei Huang
- Department of Biomedical Science, Charles E. Schmidt College of Medicine, Florida Atlantic University Boca Raton, FL, USA
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38
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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.
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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
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Friedrich FW, Flenner F, Nasib M, Eschenhagen T, Carrier L. Epigallocatechin-3-Gallate Accelerates Relaxation and Ca 2+ Transient Decay and Desensitizes Myofilaments in Healthy and Mybpc3-Targeted Knock-in Cardiomyopathic Mice. Front Physiol 2016; 7:607. [PMID: 27994558 PMCID: PMC5136558 DOI: 10.3389/fphys.2016.00607] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2016] [Accepted: 11/22/2016] [Indexed: 11/13/2022] Open
Abstract
Background: Hypertrophic cardiomyopathy (HCM) is the most common inherited cardiac muscle disease with left ventricular hypertrophy, interstitial fibrosis and diastolic dysfunction. Increased myofilament Ca2+ sensitivity could be the underlying cause of diastolic dysfunction. Epigallocatechin-3-gallate (EGCg), a catechin found in green tea, has been reported to decrease myofilament Ca2+ sensitivity in HCM models with troponin mutations. However, whether this is also the case for HCM-associated thick filament mutations is not known. Therefore, we evaluated whether EGCg affects the behavior of cardiomyocytes and myofilaments of an HCM mouse model carrying a gene mutation in cardiac myosin-binding protein C and exhibiting both increased myofilament Ca2+ sensitivity and diastolic dysfunction. Methods and Results: Acute effects of EGCg were tested on fractional sarcomere shortening and Ca2+ transients in intact ventricular myocytes and on force-Ca2+ relationship of skinned ventricular muscle strips isolated from Mybpc3-targeted knock-in (KI) and wild-type (WT) mice. Fractional sarcomere shortening and Ca2+ transients were analyzed at 37°C under 1-Hz pacing in the absence or presence of EGCg (1.8 μM). At baseline and in the absence of Fura-2, KI cardiomyocytes displayed lower diastolic sarcomere length, higher fractional sarcomere shortening, longer time to peak shortening and time to 50% relengthening than WT cardiomyocytes. In WT and KI neither diastolic sarcomere length nor fractional sarcomere shortening were influenced by EGCg treatment, but relaxation time was reduced, to a greater extent in KI cells. EGCg shortened time to peak Ca2+ and Ca2+ transient decay in Fura-2-loaded WT and KI cardiomyocytes. EGCg did not influence phosphorylation of phospholamban. In skinned cardiac muscle strips, EGCg (30 μM) decreased Ca2+ sensitivity in both groups. Conclusion: EGCg hastened relaxation and Ca2+ transient decay to a larger extent in KI than in WT cardiomyocytes. This effect could be partially explained by myofilament Ca2+ desensitization.
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Affiliation(s)
- Felix W Friedrich
- Cardiovascular Research Center, Department of Experimental Pharmacology and Toxicology, University Medical Center Hamburg-EppendorfHamburg, Germany; German Centre for Cardiovascular Research (DZHK)Hamburg, Germany
| | - Frederik Flenner
- Cardiovascular Research Center, Department of Experimental Pharmacology and Toxicology, University Medical Center Hamburg-EppendorfHamburg, Germany; German Centre for Cardiovascular Research (DZHK)Hamburg, Germany
| | - Mahtab Nasib
- Cardiovascular Research Center, Department of Experimental Pharmacology and Toxicology, University Medical Center Hamburg-EppendorfHamburg, Germany; German Centre for Cardiovascular Research (DZHK)Hamburg, Germany
| | - Thomas Eschenhagen
- Cardiovascular Research Center, Department of Experimental Pharmacology and Toxicology, University Medical Center Hamburg-EppendorfHamburg, Germany; German Centre for Cardiovascular Research (DZHK)Hamburg, Germany
| | - Lucie Carrier
- Cardiovascular Research Center, Department of Experimental Pharmacology and Toxicology, University Medical Center Hamburg-EppendorfHamburg, Germany; German Centre for Cardiovascular Research (DZHK)Hamburg, Germany
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40
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Nguyen S, Siu R, Dewey S, Cui Z, Gomes AV. Amino Acid Changes at Arginine 204 of Troponin I Result in Increased Calcium Sensitivity of Force Development. Front Physiol 2016; 7:520. [PMID: 27895589 PMCID: PMC5108889 DOI: 10.3389/fphys.2016.00520] [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: 09/01/2016] [Accepted: 10/20/2016] [Indexed: 11/26/2022] Open
Abstract
Mutations in human cardiac troponin I (cTnI) have been associated with restrictive, dilated, and hypertrophic cardiomyopathies. The most commonly occurring residue on cTnI associated with familial hypertrophic cardiomyopathy (FHC) is arginine (R), which is also the most common residue at which multiple mutations occur. Two FHC mutations are known to occur at cTnI arginine 204, R204C and R204H, and both are associated with poor clinical prognosis. The R204H mutation has also been associated with restrictive cardiomyopathy (RCM). To characterize the effects of different mutations at the same residue (R204) on the physiological function of cTnI, six mutations at R204 (C, G, H, P, Q, W) were investigated in skinned fiber studies. Skinned fiber studies showed that all tested mutations at R204 caused significant increases in Ca2+ sensitivity of force development (ΔpCa50 = 0.22–0.35) when compared to wild-type (WT) cTnI. Investigation of the interactions between the cTnI mutants and WT cardiac troponin C (cTnC) or WT cardiac troponin T (cTnT) showed that all the mutations investigated, except R204G, affected either or both cTnI:cTnT and cTnI:cTnC interactions. The R204H mutation affected both cTnI:cTnT and cTnI:cTnC interactions while the R204C mutation affected only the cTnI:cTnC interaction. These results suggest that different mutations at the same site on cTnI could have varying effects on thin filament interactions. A mutation in fast skeletal TnI (R174Q, homologous to cTnI R204Q) also significantly increased Ca2+ sensitivity of force development (ΔpCa50 = 0.16). Our studies indicate that known cTnI mutations associated with poor prognosis (R204C and R204H) exhibit large increases in Ca2+ sensitivity of force development. Therefore, other R204 mutations that cause similar increases in Ca2+ sensitivity are also likely to have poor prognoses.
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Affiliation(s)
- Susan Nguyen
- Department of Neurobiology, Physiology, and Behavior, University of California, Davis Davis, CA, USA
| | - Rylie Siu
- Department of Neurobiology, Physiology, and Behavior, University of California, Davis Davis, CA, USA
| | - Shannamar Dewey
- Department of Neurobiology, Physiology, and Behavior, University of California, Davis Davis, CA, USA
| | - Ziyou Cui
- Department of Neurobiology, Physiology, and Behavior, University of California, Davis Davis, CA, USA
| | - Aldrin V Gomes
- Department of Neurobiology, Physiology, and Behavior, University of California, DavisDavis, CA, USA; Department of Physiology and Membrane Biology, University of California, DavisDavis, CA, USA
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41
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Sewanan LR, Moore JR, Lehman W, Campbell SG. Predicting Effects of Tropomyosin Mutations on Cardiac Muscle Contraction through Myofilament Modeling. Front Physiol 2016; 7:473. [PMID: 27833562 PMCID: PMC5081029 DOI: 10.3389/fphys.2016.00473] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2016] [Accepted: 10/03/2016] [Indexed: 12/23/2022] Open
Abstract
Point mutations to the human gene TPM1 have been implicated in the development of both hypertrophic and dilated cardiomyopathies. Such observations have led to studies investigating the link between single residue changes and the biophysical behavior of the tropomyosin molecule. However, the degree to which these molecular perturbations explain the performance of intact sarcomeres containing mutant tropomyosin remains uncertain. Here, we present a modeling approach that integrates various aspects of tropomyosin's molecular properties into a cohesive paradigm representing their impact on muscle function. In particular, we considered the effects of tropomyosin mutations on (1) persistence length, (2) equilibrium between thin filament blocked and closed regulatory states, and (3) the crossbridge duty cycle. After demonstrating the ability of the new model to capture Ca-dependent myofilament responses during both dynamic and steady-state activation, we used it to capture the effects of hypertrophic cardiomyopathy (HCM) related E180G and D175N mutations on skinned myofiber mechanics. Our analysis indicates that the fiber-level effects of the two mutations can be accurately described by a combination of changes to the three tropomyosin properties represented in the model. Subsequently, we used the model to predict mutation effects on muscle twitch. Both mutations led to increased twitch contractility as a consequence of diminished cooperative inhibition between thin filament regulatory units. Overall, simulations suggest that a common twitch phenotype for HCM-linked tropomyosin mutations includes both increased contractility and elevated diastolic tension.
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Affiliation(s)
- Lorenzo R Sewanan
- Department of Biomedical Engineering, Yale UniversityNew Haven, CT, USA; Yale School of Medicine, Yale UniversityNew Haven, CT, USA
| | - Jeffrey R Moore
- Department of Biological Sciences, University of Massachusetts Lowell Lowell, MA, USA
| | - William Lehman
- Department of Physiology and Biophysics, Boston University School of Medicine Boston, MA, USA
| | - Stuart G Campbell
- Department of Biomedical Engineering, Yale UniversityNew Haven, CT, USA; Department of Cellular and Molecular Physiology, Yale School of MedicineNew Haven, CT, USA
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The genetic basis of hypertrophic cardiomyopathy in cats and humans. J Vet Cardiol 2016; 17 Suppl 1:S53-73. [PMID: 26776594 DOI: 10.1016/j.jvc.2015.03.001] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2014] [Revised: 01/16/2015] [Accepted: 03/16/2015] [Indexed: 12/19/2022]
Abstract
Mutations in genes that encode for muscle sarcomeric proteins have been identified in humans and two breeds of domestic cats with hypertrophic cardiomyopathy (HCM). This article reviews the history, genetics, and pathogenesis of HCM in the two species in order to give veterinarians a perspective on the genetics of HCM. Hypertrophic cardiomyopathy in people is a genetic disease that has been called a disease of the sarcomere because the preponderance of mutations identified that cause HCM are in genes that encode for sarcomeric proteins (Maron and Maron, 2013). Sarcomeres are the basic contractile units of muscle and thus sarcomeric proteins are responsible for the strength, speed, and extent of muscle contraction. In people with HCM, the two most common genes affected by HCM mutations are the myosin heavy chain gene (MYH7), the gene that encodes for the motor protein β-myosin heavy chain (the sarcomeric protein that splits ATP to generate force), and the cardiac myosin binding protein-C gene (MYBPC3), a gene that encodes for the closely related structural and regulatory protein, cardiac myosin binding protein-C (cMyBP-C). To date, the two mutations linked to HCM in domestic cats (one each in Maine Coon and Ragdoll breeds) also occur in MYBPC3 (Meurs et al., 2005, 2007). This is a review of the genetics of HCM in both humans and domestic cats that focuses on the aspects of human genetics that are germane to veterinarians and on all aspects of feline HCM genetics.
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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.
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Cheng Y, Regnier M. Cardiac troponin structure-function and the influence of hypertrophic cardiomyopathy associated mutations on modulation of contractility. Arch Biochem Biophys 2016; 601:11-21. [PMID: 26851561 PMCID: PMC4899195 DOI: 10.1016/j.abb.2016.02.004] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2015] [Revised: 01/30/2016] [Accepted: 02/02/2016] [Indexed: 11/29/2022]
Abstract
Cardiac troponin (cTn) acts as a pivotal regulator of muscle contraction and relaxation and is composed of three distinct subunits (cTnC: a highly conserved Ca(2+) binding subunit, cTnI: an actomyosin ATPase inhibitory subunit, and cTnT: a tropomyosin binding subunit). In this mini-review, we briefly summarize the structure-function relationship of cTn and its subunits, its modulation by PKA-mediated phosphorylation of cTnI, and what is known about how these properties are altered by hypertrophic cardiomyopathy (HCM) associated mutations of cTnI. This includes recent work using computational modeling approaches to understand the atomic-based structural level basis of disease-associated mutations. We propose a viewpoint that it is alteration of cTnC-cTnI interaction (rather than the Ca(2+) binding properties of cTn) per se that disrupt the ability of PKA-mediated phosphorylation at cTnI Ser-23/24 to alter contraction and relaxation in at least some HCM-associated mutations. The combination of state of the art biophysical approaches can provide new insight on the structure-function mechanisms of contractile dysfunction resulting cTnI mutations and exciting new avenues for the diagnosis, prevention, and even treatment of heart diseases.
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Affiliation(s)
- Yuanhua Cheng
- University of Washington, Department of Bioengineering, Seattle, WA, USA
| | - Michael Regnier
- University of Washington, Department of Bioengineering, Seattle, WA, USA.
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Lang SE, Stevenson TK, Xu D, O'Connell R, Westfall MV. Functionally conservative substitutions at cardiac troponin I S43/45. Arch Biochem Biophys 2016; 601:42-7. [PMID: 26869200 PMCID: PMC4899172 DOI: 10.1016/j.abb.2016.02.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2015] [Revised: 01/13/2016] [Accepted: 02/01/2016] [Indexed: 12/22/2022]
Abstract
A phospho-null Ala substitution at protein kinase C (PKC)-targeted cardiac troponin I (cTnI) S43/45 reduces myocyte and cardiac contractile function. The goal of the current study was to test whether cTnIS43/45N is an alternative, functionally conservative substitution in cardiac myocytes. Partial and more extensive endogenous cTnI replacement was similar at 2 and 4 days after gene transfer, respectively, for epitope-tagged cTnI and cTnIS43/45N. This replacement did not significantly change thin filament stoichiometry. In functional studies, there were no significant changes in the amplitude and/or rates of contractile shortening and re-lengthening after this partial (2 days) and extensive (4 days) replacement with cTnIS43/45N. The cTnIS43/45N substitution also was not associated with adaptive changes in the myocyte Ca(2+) transient or in phosphorylation of the protein kinase A and C-targeted cTnIS23/24 site. These results provide evidence that cTnIS43/45N is a functionally conservative substitution, and may be appropriate for use as a phospho-null in rodent models designed for studies on PKC modulation of cardiac performance.
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Affiliation(s)
- Sarah E Lang
- Program in Cellular and Molecular Biology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Tamara K Stevenson
- Department of Cardiac Surgery, University of Michigan, Ann Arbor, MI 48109, USA; Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Dongyang Xu
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI 48109, USA
| | - Ryan O'Connell
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Margaret V Westfall
- Program in Cellular and Molecular Biology, University of Michigan, Ann Arbor, MI 48109, USA; Department of Cardiac Surgery, University of Michigan, Ann Arbor, MI 48109, USA; Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI 48109, USA; Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI 48109, USA.
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Pan B, Xu ZW, Xu Y, Liu LJ, Zhu J, Wang X, Nan C, Zhang Z, Shen W, Huang XP, Tian J. Diastolic dysfunction and cardiac troponin I decrease in aging hearts. Arch Biochem Biophys 2016; 603:20-8. [PMID: 27184165 DOI: 10.1016/j.abb.2016.05.008] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2016] [Revised: 05/07/2016] [Accepted: 05/11/2016] [Indexed: 11/28/2022]
Abstract
Cardiac tropnoin I (cTnI) plays a critical role in the regulation of diastolic function, and its low expression may result in cardiac diastolic dysfunction, which is the most common form of cardiovascular disorders in older adults. In this study, cTnI expression levels were determined in mice at various ages and cardiac function was measured and compared between young adult mice (3 and 10 months) and older mice (18 months). The data indicated that the cTnI levels reached a peak high in young adult hearts (3 months), but decreased in older hearts (18 months). Furthermore, the older hearts showed a significant diastolic dysfunction observed by P-V loop and echocardiography measurements. To further define the mechanism underlying the cTnI decrease in aging hearts, we tested DNA methylation and histone acetylation modifications of cTnI gene. We found that acetylation of histone near the promoter region of cTnI gene played an important role in regulation of cTnI expression in the heart at different ages. Our study indicates that epigenetic modification caused cTnI expression decrease is one of the possible causes that result in a reduced cTnI level and diastolic dysfunction in the older hearts.
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Affiliation(s)
- B Pan
- Heart Centre, Children's Hospital of Chongqing Medical University, Chongqing, PR China; Key Laboratory of Developmental Disease in Childhood (Chongqing Medical University), Ministry of Education, Chongqing, PR China; Key Laboratory of Pediatrics in Chongqing, PR China; Chongqing International Science and Technology Cooperation Center for Child Development and Disorders, PR China
| | - Z W Xu
- Heart Centre, Children's Hospital of Chongqing Medical University, Chongqing, PR China; Key Laboratory of Developmental Disease in Childhood (Chongqing Medical University), Ministry of Education, Chongqing, PR China; Key Laboratory of Pediatrics in Chongqing, PR China; Chongqing International Science and Technology Cooperation Center for Child Development and Disorders, PR China
| | - Y Xu
- Heart Centre, Children's Hospital of Chongqing Medical University, Chongqing, PR China; Key Laboratory of Developmental Disease in Childhood (Chongqing Medical University), Ministry of Education, Chongqing, PR China; Key Laboratory of Pediatrics in Chongqing, PR China; Chongqing International Science and Technology Cooperation Center for Child Development and Disorders, PR China
| | - L J Liu
- Key Laboratory of Developmental Disease in Childhood (Chongqing Medical University), Ministry of Education, Chongqing, PR China; Key Laboratory of Pediatrics in Chongqing, PR China; Chongqing International Science and Technology Cooperation Center for Child Development and Disorders, PR China
| | - J Zhu
- Key Laboratory of Developmental Disease in Childhood (Chongqing Medical University), Ministry of Education, Chongqing, PR China; Key Laboratory of Pediatrics in Chongqing, PR China; Chongqing International Science and Technology Cooperation Center for Child Development and Disorders, PR China
| | - X Wang
- Department of Biomedical Science, Charlie E. Schmidt College of Medicine, Florida Atlantic University, Boca Raton, FL, USA
| | - C Nan
- Department of Biomedical Science, Charlie E. Schmidt College of Medicine, Florida Atlantic University, Boca Raton, FL, USA
| | - Z Zhang
- Department of Biomedical Science, Charlie E. Schmidt College of Medicine, Florida Atlantic University, Boca Raton, FL, USA
| | - W Shen
- Department of Biomedical Science, Charlie E. Schmidt College of Medicine, Florida Atlantic University, Boca Raton, FL, USA
| | - X P Huang
- Department of Biomedical Science, Charlie E. Schmidt College of Medicine, Florida Atlantic University, Boca Raton, FL, USA.
| | - J Tian
- Heart Centre, Children's Hospital of Chongqing Medical University, Chongqing, PR China.
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Warren CM, Karam CN, Wolska BM, Kobayashi T, de Tombe PP, Arteaga GM, Bos JM, Ackerman MJ, Solaro RJ. Green Tea Catechin Normalizes the Enhanced Ca2+ Sensitivity of Myofilaments Regulated by a Hypertrophic Cardiomyopathy-Associated Mutation in Human Cardiac Troponin I (K206I). ACTA ACUST UNITED AC 2015; 8:765-73. [PMID: 26553696 DOI: 10.1161/circgenetics.115.001234] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2015] [Accepted: 11/06/2015] [Indexed: 11/16/2022]
Abstract
BACKGROUND Hypertrophic cardiomyopathy (HCM) is the most common inherited cardiovascular disease characterized by thickening of ventricular walls and decreased left ventricular chamber volume. The majority of HCM-associated mutations are found in genes encoding sarcomere proteins. Herein, we set out to functionally characterize a novel HCM-associated mutation (K206I-TNNI3) and elucidate the mechanism of dysfunction at the level of myofilament proteins. METHODS AND RESULTS The male index case was diagnosed with HCM after an out-of-hospital cardiac arrest, which was followed by comprehensive clinical evaluation, transthoracic echocardiography, and clinical genetic testing. To determine molecular mechanism(s) of the mutant human cardiac troponin I (K206I), we tested the Ca(2+) dependence of thin filament-activated myosin-S1-ATPase activity in a reconstituted, regulated, actomyosin system comparing wild-type human troponin complex, 50% mix of K206I/wildtype, or 100% K206I. We also exchanged native troponin detergent extracted fibers with reconstituted troponin containing either wildtype or a 65% mix of K206I/wildtype and measured force generation. The Ca(2+) sensitivity of the myofilaments containing the K206I variant was significantly increased, and when treated with 20 µmol/L (-)-epigallocatechin gallate (green tea) was restored back to wild-type levels in ATPase and force measurements. The K206I mutation impairs the ability of the troponin I to inhibit ATPase activity in the absence of calcium-bound human cardiac troponin C. The ability of calcium-bound human cardiac troponin C to neutralize the inhibition of K206I was greater than with wild-type TnI. CONCLUSIONS Compromised interactions of K206I with actin and hcTnC may lead to impaired relaxation and HCM.
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Affiliation(s)
- Chad M Warren
- From the Department of Physiology and Biophysics, Center for Cardiovascular Research (C.M.W., C.N.K., B.M.W., T.K., R.J.S.) and Division of Cardiology, Department of Medicine (B.M.W.), University of Illinois at Chicago; Department of Cell and Molecular Physiology, Stritch School of Medicine, Loyola University Chicago, Maywood, IL (P.P.d.T.); and Division of Pediatric Critical Care and Physiology, Department of Pediatrics (G.M.A.), Department of Molecular Pharmacology and Experimental Therapeutics, Windland Smith Rice Sudden Death Genomics Laboratory (J.M.B., M.J.A.), Division of Pediatric Cardiology, Department of Pediatrics (J.M.B., M.J.A.), and Division of Cardiovascular Diseases, Department of Medicine (M.J.A.), Mayo Clinic, Rochester, MN
| | - Chehade N Karam
- From the Department of Physiology and Biophysics, Center for Cardiovascular Research (C.M.W., C.N.K., B.M.W., T.K., R.J.S.) and Division of Cardiology, Department of Medicine (B.M.W.), University of Illinois at Chicago; Department of Cell and Molecular Physiology, Stritch School of Medicine, Loyola University Chicago, Maywood, IL (P.P.d.T.); and Division of Pediatric Critical Care and Physiology, Department of Pediatrics (G.M.A.), Department of Molecular Pharmacology and Experimental Therapeutics, Windland Smith Rice Sudden Death Genomics Laboratory (J.M.B., M.J.A.), Division of Pediatric Cardiology, Department of Pediatrics (J.M.B., M.J.A.), and Division of Cardiovascular Diseases, Department of Medicine (M.J.A.), Mayo Clinic, Rochester, MN
| | - Beata M Wolska
- From the Department of Physiology and Biophysics, Center for Cardiovascular Research (C.M.W., C.N.K., B.M.W., T.K., R.J.S.) and Division of Cardiology, Department of Medicine (B.M.W.), University of Illinois at Chicago; Department of Cell and Molecular Physiology, Stritch School of Medicine, Loyola University Chicago, Maywood, IL (P.P.d.T.); and Division of Pediatric Critical Care and Physiology, Department of Pediatrics (G.M.A.), Department of Molecular Pharmacology and Experimental Therapeutics, Windland Smith Rice Sudden Death Genomics Laboratory (J.M.B., M.J.A.), Division of Pediatric Cardiology, Department of Pediatrics (J.M.B., M.J.A.), and Division of Cardiovascular Diseases, Department of Medicine (M.J.A.), Mayo Clinic, Rochester, MN
| | - Tomoyoshi Kobayashi
- From the Department of Physiology and Biophysics, Center for Cardiovascular Research (C.M.W., C.N.K., B.M.W., T.K., R.J.S.) and Division of Cardiology, Department of Medicine (B.M.W.), University of Illinois at Chicago; Department of Cell and Molecular Physiology, Stritch School of Medicine, Loyola University Chicago, Maywood, IL (P.P.d.T.); and Division of Pediatric Critical Care and Physiology, Department of Pediatrics (G.M.A.), Department of Molecular Pharmacology and Experimental Therapeutics, Windland Smith Rice Sudden Death Genomics Laboratory (J.M.B., M.J.A.), Division of Pediatric Cardiology, Department of Pediatrics (J.M.B., M.J.A.), and Division of Cardiovascular Diseases, Department of Medicine (M.J.A.), Mayo Clinic, Rochester, MN
| | - Pieter P de Tombe
- From the Department of Physiology and Biophysics, Center for Cardiovascular Research (C.M.W., C.N.K., B.M.W., T.K., R.J.S.) and Division of Cardiology, Department of Medicine (B.M.W.), University of Illinois at Chicago; Department of Cell and Molecular Physiology, Stritch School of Medicine, Loyola University Chicago, Maywood, IL (P.P.d.T.); and Division of Pediatric Critical Care and Physiology, Department of Pediatrics (G.M.A.), Department of Molecular Pharmacology and Experimental Therapeutics, Windland Smith Rice Sudden Death Genomics Laboratory (J.M.B., M.J.A.), Division of Pediatric Cardiology, Department of Pediatrics (J.M.B., M.J.A.), and Division of Cardiovascular Diseases, Department of Medicine (M.J.A.), Mayo Clinic, Rochester, MN
| | - Grace M Arteaga
- From the Department of Physiology and Biophysics, Center for Cardiovascular Research (C.M.W., C.N.K., B.M.W., T.K., R.J.S.) and Division of Cardiology, Department of Medicine (B.M.W.), University of Illinois at Chicago; Department of Cell and Molecular Physiology, Stritch School of Medicine, Loyola University Chicago, Maywood, IL (P.P.d.T.); and Division of Pediatric Critical Care and Physiology, Department of Pediatrics (G.M.A.), Department of Molecular Pharmacology and Experimental Therapeutics, Windland Smith Rice Sudden Death Genomics Laboratory (J.M.B., M.J.A.), Division of Pediatric Cardiology, Department of Pediatrics (J.M.B., M.J.A.), and Division of Cardiovascular Diseases, Department of Medicine (M.J.A.), Mayo Clinic, Rochester, MN
| | - J Martijn Bos
- From the Department of Physiology and Biophysics, Center for Cardiovascular Research (C.M.W., C.N.K., B.M.W., T.K., R.J.S.) and Division of Cardiology, Department of Medicine (B.M.W.), University of Illinois at Chicago; Department of Cell and Molecular Physiology, Stritch School of Medicine, Loyola University Chicago, Maywood, IL (P.P.d.T.); and Division of Pediatric Critical Care and Physiology, Department of Pediatrics (G.M.A.), Department of Molecular Pharmacology and Experimental Therapeutics, Windland Smith Rice Sudden Death Genomics Laboratory (J.M.B., M.J.A.), Division of Pediatric Cardiology, Department of Pediatrics (J.M.B., M.J.A.), and Division of Cardiovascular Diseases, Department of Medicine (M.J.A.), Mayo Clinic, Rochester, MN
| | - Michael J Ackerman
- From the Department of Physiology and Biophysics, Center for Cardiovascular Research (C.M.W., C.N.K., B.M.W., T.K., R.J.S.) and Division of Cardiology, Department of Medicine (B.M.W.), University of Illinois at Chicago; Department of Cell and Molecular Physiology, Stritch School of Medicine, Loyola University Chicago, Maywood, IL (P.P.d.T.); and Division of Pediatric Critical Care and Physiology, Department of Pediatrics (G.M.A.), Department of Molecular Pharmacology and Experimental Therapeutics, Windland Smith Rice Sudden Death Genomics Laboratory (J.M.B., M.J.A.), Division of Pediatric Cardiology, Department of Pediatrics (J.M.B., M.J.A.), and Division of Cardiovascular Diseases, Department of Medicine (M.J.A.), Mayo Clinic, Rochester, MN
| | - R John Solaro
- From the Department of Physiology and Biophysics, Center for Cardiovascular Research (C.M.W., C.N.K., B.M.W., T.K., R.J.S.) and Division of Cardiology, Department of Medicine (B.M.W.), University of Illinois at Chicago; Department of Cell and Molecular Physiology, Stritch School of Medicine, Loyola University Chicago, Maywood, IL (P.P.d.T.); and Division of Pediatric Critical Care and Physiology, Department of Pediatrics (G.M.A.), Department of Molecular Pharmacology and Experimental Therapeutics, Windland Smith Rice Sudden Death Genomics Laboratory (J.M.B., M.J.A.), Division of Pediatric Cardiology, Department of Pediatrics (J.M.B., M.J.A.), and Division of Cardiovascular Diseases, Department of Medicine (M.J.A.), Mayo Clinic, Rochester, MN.
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Figueiredo-Freitas C, Dulce RA, Foster MW, Liang J, Yamashita AMS, Lima-Rosa FL, Thompson JW, Moseley MA, Hare JM, Nogueira L, Sorenson MM, Pinto JR. S-Nitrosylation of Sarcomeric Proteins Depresses Myofilament Ca2+)Sensitivity in Intact Cardiomyocytes. Antioxid Redox Signal 2015; 23:1017-34. [PMID: 26421519 PMCID: PMC4649751 DOI: 10.1089/ars.2015.6275] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
AIMS The heart responds to physiological and pathophysiological stress factors by increasing its production of nitric oxide (NO), which reacts with intracellular glutathione to form S-nitrosoglutathione (GSNO), a protein S-nitrosylating agent. Although S-nitrosylation protects some cardiac proteins against oxidative stress, direct effects on myofilament performance are unknown. We hypothesize that S-nitrosylation of sarcomeric proteins will modulate the performance of cardiac myofilaments. RESULTS Incubation of intact mouse cardiomyocytes with S-nitrosocysteine (CysNO, a cell-permeable low-molecular-weight nitrosothiol) significantly decreased myofilament Ca(2+) sensitivity. In demembranated (skinned) fibers, S-nitrosylation with 1 μM GSNO also decreased Ca(2+) sensitivity of contraction and 10 μM reduced maximal isometric force, while inhibition of relaxation and myofibrillar ATPase required higher concentrations (≥ 100 μM). Reducing S-nitrosylation with ascorbate partially reversed the effects on Ca(2+) sensitivity and ATPase activity. In live cardiomyocytes treated with CysNO, resin-assisted capture of S-nitrosylated protein thiols was combined with label-free liquid chromatography-tandem mass spectrometry to quantify S-nitrosylation and determine the susceptible cysteine sites on myosin, actin, myosin-binding protein C, troponin C and I, tropomyosin, and titin. The ability of sarcomere proteins to form S-NO from 10-500 μM CysNO in intact cardiomyocytes was further determined by immunoblot, with actin, myosin, myosin-binding protein C, and troponin C being the more susceptible sarcomeric proteins. INNOVATION AND CONCLUSIONS Thus, specific physiological effects are associated with S-nitrosylation of a limited number of cysteine residues in sarcomeric proteins, which also offer potential targets for interventions in pathophysiological situations.
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Affiliation(s)
- Cícero Figueiredo-Freitas
- 1 Department of Biomedical Sciences, College of Medicine, Florida State University , Tallahassee, Florida.,2 Instituto de Bioquímica Médica Leopoldo de Meis (IBqM), Federal University of Rio de Janeiro , Rio de Janeiro, Brazil .,3 Department of Molecular and Cellular Pharmacology, Miller School of Medicine, University of Miami , Miami, Florida
| | - Raul A Dulce
- 4 Interdisciplinary Stem Cell Institute, University of Miami , Miami, Florida
| | - Matthew W Foster
- 5 Pulmonary, Allergy and Critical Care Medicine, Duke University Medical Center , Durham, North Carolina.,6 Proteomics and Metabolomics Shared Resource, Duke University Medical Center , Durham, North Carolina
| | - Jingsheng Liang
- 3 Department of Molecular and Cellular Pharmacology, Miller School of Medicine, University of Miami , Miami, Florida
| | - Aline M S Yamashita
- 2 Instituto de Bioquímica Médica Leopoldo de Meis (IBqM), Federal University of Rio de Janeiro , Rio de Janeiro, Brazil
| | - Frederico L Lima-Rosa
- 2 Instituto de Bioquímica Médica Leopoldo de Meis (IBqM), Federal University of Rio de Janeiro , Rio de Janeiro, Brazil
| | - J Will Thompson
- 6 Proteomics and Metabolomics Shared Resource, Duke University Medical Center , Durham, North Carolina
| | - M Arthur Moseley
- 6 Proteomics and Metabolomics Shared Resource, Duke University Medical Center , Durham, North Carolina
| | - Joshua M Hare
- 4 Interdisciplinary Stem Cell Institute, University of Miami , Miami, Florida
| | - Leonardo Nogueira
- 2 Instituto de Bioquímica Médica Leopoldo de Meis (IBqM), Federal University of Rio de Janeiro , Rio de Janeiro, Brazil
| | - Martha M Sorenson
- 2 Instituto de Bioquímica Médica Leopoldo de Meis (IBqM), Federal University of Rio de Janeiro , Rio de Janeiro, Brazil
| | - José Renato Pinto
- 1 Department of Biomedical Sciences, College of Medicine, Florida State University , Tallahassee, Florida.,3 Department of Molecular and Cellular Pharmacology, Miller School of Medicine, University of Miami , Miami, Florida
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50
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Davis RT, Simon JN, Utter M, Mungai P, Alvarez MG, Chowdhury SAK, Heydemann A, Ke Y, Wolska BM, Solaro RJ. Knockout of p21-activated kinase-1 attenuates exercise-induced cardiac remodelling through altered calcineurin signalling. Cardiovasc Res 2015; 108:335-47. [PMID: 26464331 DOI: 10.1093/cvr/cvv234] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Accepted: 10/03/2015] [Indexed: 01/14/2023] Open
Abstract
AIMS Despite its known cardiovascular benefits, the intracellular signalling mechanisms underlying physiological cardiac growth remain poorly understood. Therefore, the purpose of this study was to investigate a novel role of p21-activated kinase-1 (Pak1) in the regulation of exercise-induced cardiac hypertrophy. METHODS AND RESULTS Wild-type (WT) and Pak1 KO mice were subjected to 6 weeks of treadmill endurance exercise training (ex-training). Cardiac function was assessed via echocardiography, in situ haemodynamics, and the pCa-force relations in skinned fibre preparations at baseline and at the end of the training regimen. Post-translational modifications to the sarcomeric proteins and expression levels of calcium-regulating proteins were also assessed following ex-training. Heart weight/tibia length and echocardiography data revealed that there was marked hypertrophy following ex-training in the WT mice, which was not evident in the KO mice. Additionally, following ex-training, WT mice demonstrated an increase in cardiac contractility, myofilament calcium sensitivity, and phosphorylation of cardiac myosin-binding protein C, cardiac TnT, and tropomyosin compared with KO mice. With ex-training in WT mice, there were also increased protein levels of calcineurin and increased phosphorylation of phospholamban. CONCLUSIONS Our data suggest that Pak1 is essential for adaptive physiological cardiac remodelling and support previous evidence that demonstrates Pak1 signalling is important for cardiac growth and survival.
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Affiliation(s)
- Robert T Davis
- Department of Physiology and Biophysics, Center for Cardiovascular Research, University of Illinois at Chicago, 835 S. Wolcott Ave-Rm. E202, Chicago, IL 60612, USA
| | - Jillian N Simon
- Department of Physiology and Biophysics, Center for Cardiovascular Research, University of Illinois at Chicago, 835 S. Wolcott Ave-Rm. E202, Chicago, IL 60612, USA
| | - Megan Utter
- Department of Physiology and Biophysics, Center for Cardiovascular Research, University of Illinois at Chicago, 835 S. Wolcott Ave-Rm. E202, Chicago, IL 60612, USA
| | - Paul Mungai
- Department of Physiology and Biophysics, Center for Cardiovascular Research, University of Illinois at Chicago, 835 S. Wolcott Ave-Rm. E202, Chicago, IL 60612, USA
| | - Manuel G Alvarez
- Department of Physiology and Biophysics, Center for Cardiovascular Research, University of Illinois at Chicago, 835 S. Wolcott Ave-Rm. E202, Chicago, IL 60612, USA
| | - Shamim A K Chowdhury
- Department of Physiology and Biophysics, Center for Cardiovascular Research, University of Illinois at Chicago, 835 S. Wolcott Ave-Rm. E202, Chicago, IL 60612, USA
| | - Ahlke Heydemann
- Department of Physiology and Biophysics, Center for Cardiovascular Research, University of Illinois at Chicago, 835 S. Wolcott Ave-Rm. E202, Chicago, IL 60612, USA
| | - Yunbo Ke
- Department of Physiology and Biophysics, Center for Cardiovascular Research, University of Illinois at Chicago, 835 S. Wolcott Ave-Rm. E202, Chicago, IL 60612, USA
| | - Beata M Wolska
- Department of Physiology and Biophysics, Center for Cardiovascular Research, University of Illinois at Chicago, 835 S. Wolcott Ave-Rm. E202, Chicago, IL 60612, USA Department of Medicine, Section of Cardiology, Center for Cardiovascular Research, University of Illinois, Chicago, IL 60612, USA
| | - R John Solaro
- Department of Physiology and Biophysics, Center for Cardiovascular Research, University of Illinois at Chicago, 835 S. Wolcott Ave-Rm. E202, Chicago, IL 60612, USA
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