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Solís C, Warren CM, Dittloff K, DiNello E, Solaro RJ, Russell B. Cardiomyocyte external mechanical unloading activates modifications of α-actinin differently from sarcomere-originated unloading. FEBS J 2023; 290:5322-5339. [PMID: 37551968 DOI: 10.1111/febs.16925] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Revised: 06/26/2023] [Accepted: 08/07/2023] [Indexed: 08/09/2023]
Abstract
Loss of myocardial mass in a neonatal rat cardiomyocyte culture is studied to determine whether there is a distinguishable cellular response based on the origin of mechano-signals. The approach herein compares the sarcomeric assembly and disassembly processes in heart cells by imposing mechano-signals at the interface with the extracellular matrix (extrinsic) and at the level of the myofilaments (intrinsic). Experiments compared the effects of imposed internal (inside/out) and external (outside/in) loading and unloading on modifications in neonatal rat cardiomyocytes. Unloading of the cellular substrate by myosin inhibition (1 μm mavacamten), or cessation of cyclic strain (1 Hz, 10% strain) after preconditioning, led to significant disassembly of sarcomeric α-actinin by 6 h. In myosin inhibition, this was accompanied by redistribution of intracellular poly-ubiquitin K48 to the cellular periphery relative to the poly-ubiquitin K48 reservoir at the I-band. Moreover, loading and unloading of the cellular substrate led to a three-fold increase in post-translational modifications (PTMs) when compared to the myosin-specific activation or inhibition. Specifically, phosphorylation increased with loading while ubiquitination increased with unloading, which may involve extracellular signal-regulated kinase 1/2 and focal adhesion kinase activation. The identified PTMs, including ubiquitination, acetylation, and phosphorylation, are proposed to modify internal domains in α-actinin to increase its propensity to bind F-actin. These results demonstrate a link between mechanical feedback and sarcomere protein homeostasis via PTMs of α-actinin that exemplify how cardiomyocytes exhibit differential responses to the origin of force. The implications of sarcomere regulation governed by PTMs of α-actinin are discussed with respect to cardiac atrophy and heart failure.
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Affiliation(s)
- Christopher Solís
- Department of Physiology and Biophysics, Center for Cardiovascular Research, University of Illinois at Chicago, IL, USA
| | - Chad M Warren
- Department of Physiology and Biophysics, Center for Cardiovascular Research, University of Illinois at Chicago, IL, USA
| | - Kyle Dittloff
- Department of Physiology and Biophysics, Center for Cardiovascular Research, University of Illinois at Chicago, IL, USA
| | - Elisabeth DiNello
- Department of Physiology and Biophysics, Center for Cardiovascular Research, University of Illinois at Chicago, IL, USA
| | - R John Solaro
- Department of Physiology and Biophysics, Center for Cardiovascular Research, University of Illinois at Chicago, IL, USA
| | - Brenda Russell
- Department of Physiology and Biophysics, Center for Cardiovascular Research, University of Illinois at Chicago, IL, USA
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Perike S, Gonzalez-Gonzalez FJ, Abu-Taha I, Damen FW, Hanft LM, Lizama KS, Aboonabi A, Capote AE, Aguilar-Sanchez Y, Levin B, Han Z, Sridhar A, Grand J, Martin J, Akar JG, Warren CM, Solaro RJ, Sang-Ging O, Darbar D, McDonald KS, Goergen CJ, Wolska BM, Dobrev D, Wehrens XH, McCauley MD. PPP1R12C Promotes Atrial Hypocontractility in Atrial Fibrillation. Circ Res 2023; 133:758-771. [PMID: 37737016 PMCID: PMC10616980 DOI: 10.1161/circresaha.123.322516] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Accepted: 09/14/2023] [Indexed: 09/23/2023]
Abstract
BACKGROUND Atrial fibrillation (AF)-the most common sustained cardiac arrhythmia-increases thromboembolic stroke risk 5-fold. Although atrial hypocontractility contributes to stroke risk in AF, the molecular mechanisms reducing myofilament contractile function remain unknown. We tested the hypothesis that increased expression of PPP1R12C (protein phosphatase 1 regulatory subunit 12C)-the PP1 (protein phosphatase 1) regulatory subunit targeting MLC2a (atrial myosin light chain 2)-causes hypophosphorylation of MLC2a and results in atrial hypocontractility. METHODS Right atrial appendage tissues were isolated from human patients with AF versus sinus rhythm controls. Western blots, coimmunoprecipitation, and phosphorylation studies were performed to examine how the PP1c (PP1 catalytic subunit)-PPP1R12C interaction causes MLC2a dephosphorylation. In vitro studies of pharmacological MRCK (myotonic dystrophy kinase-related Cdc42-binding kinase) inhibitor (BDP5290) in atrial HL-1 cells were performed to evaluate PP1 holoenzyme activity on MLC2a. Cardiac-specific lentiviral PPP1R12C overexpression was performed in mice to evaluate atrial remodeling with atrial cell shortening assays, echocardiography, and AF inducibility with electrophysiology studies. RESULTS In human patients with AF, PPP1R12C expression was increased 2-fold versus sinus rhythm controls (P=2.0×10-2; n=12 and 12 in each group) with >40% reduction in MLC2a phosphorylation (P=1.4×10-6; n=12 and 12 in each group). PPP1R12C-PP1c binding and PPP1R12C-MLC2a binding were significantly increased in AF (P=2.9×10-2 and 6.7×10-3, respectively; n=8 and 8 in each group). In vitro studies utilizing drug BDP5290, which inhibits T560-PPP1R12C phosphorylation, demonstrated increased PPP1R12C binding with both PP1c and MLC2a and dephosphorylation of MLC2a. Mice treated with lentiviral PPP1R12C vector demonstrated a 150% increase in left atrial size versus controls (P=5.0×10-6; n=12, 8, and 12), with reduced atrial strain and atrial ejection fraction. Pacing-induced AF in mice treated with lentiviral PPP1R12C vector was significantly higher than in controls (P=1.8×10-2 and 4.1×10-2, respectively; n=6, 6, and 5). CONCLUSIONS Patients with AF exhibit increased levels of PPP1R12C protein compared with controls. PPP1R12C overexpression in mice increases PP1c targeting to MLC2a and causes MLC2a dephosphorylation, which reduces atrial contractility and increases AF inducibility. These findings suggest that PP1 regulation of sarcomere function at MLC2a is a key determinant of atrial contractility in AF.
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Affiliation(s)
- Srikanth Perike
- Division of Cardiology, Department of Medicine, College of Medicine, University of Illinois at Chicago
- Department of Physiology and Biophysics and the Center for Cardiovascular Research, University of Illinois at Chicago
- Jesse Brown VA Medical Center, Chicago, IL
| | - Francisco J. Gonzalez-Gonzalez
- Division of Cardiology, Department of Medicine, College of Medicine, University of Illinois at Chicago
- Department of Physiology and Biophysics and the Center for Cardiovascular Research, University of Illinois at Chicago
- Jesse Brown VA Medical Center, Chicago, IL
| | - Issam Abu-Taha
- Institute of Pharmacology, West German Heart and Vascular Center, University Duisburg-Essen, Germany
| | - Frederick W. Damen
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN
| | - Laurin M. Hanft
- Department of Medical Pharmacology and Physiology, University of Missouri, Columbia
| | - Ken S. Lizama
- Division of Cardiology, Department of Medicine, College of Medicine, University of Illinois at Chicago
- Department of Physiology and Biophysics and the Center for Cardiovascular Research, University of Illinois at Chicago
- Jesse Brown VA Medical Center, Chicago, IL
| | - Anahita Aboonabi
- Division of Cardiology, Department of Medicine, College of Medicine, University of Illinois at Chicago
- Department of Physiology and Biophysics and the Center for Cardiovascular Research, University of Illinois at Chicago
| | - Andrielle E. Capote
- Division of Cardiology, Department of Medicine, College of Medicine, University of Illinois at Chicago
- Department of Physiology and Biophysics and the Center for Cardiovascular Research, University of Illinois at Chicago
| | - Yuriana Aguilar-Sanchez
- Department of Integrative Physiology and The Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX
| | | | - Zhenbo Han
- Department of Pharmacology and Regenerative Medicine, College of Medicine,University of Illinois at Chicago
| | - Arvind Sridhar
- Division of Cardiology, Department of Medicine, College of Medicine, University of Illinois at Chicago
| | - Jacob Grand
- Division of Cardiology, Department of Medicine, College of Medicine, University of Illinois at Chicago
| | | | | | - Chad M. Warren
- Department of Physiology and Biophysics and the Center for Cardiovascular Research, University of Illinois at Chicago
| | - R. John Solaro
- Department of Physiology and Biophysics and the Center for Cardiovascular Research, University of Illinois at Chicago
| | - Ong Sang-Ging
- Division of Cardiology, Department of Medicine, College of Medicine, University of Illinois at Chicago
- Department of Pharmacology and Regenerative Medicine, College of Medicine,University of Illinois at Chicago
| | - Dawood Darbar
- Division of Cardiology, Department of Medicine, College of Medicine, University of Illinois at Chicago
- Department of Physiology and Biophysics and the Center for Cardiovascular Research, University of Illinois at Chicago
- Jesse Brown VA Medical Center, Chicago, IL
| | - Kerry S. McDonald
- Department of Medical Pharmacology and Physiology, University of Missouri, Columbia
| | - Craig J. Goergen
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN
| | - Beata M. Wolska
- Division of Cardiology, Department of Medicine, College of Medicine, University of Illinois at Chicago
- Department of Physiology and Biophysics and the Center for Cardiovascular Research, University of Illinois at Chicago
| | - Dobromir Dobrev
- Institute of Pharmacology, West German Heart and Vascular Center, University Duisburg-Essen, Germany
- Department of Integrative Physiology and The Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX
- Department of Medicine, Montréal Heart Institute and Université de Montréal, Montréal, Canada
| | - Xander H.T. Wehrens
- Department of Integrative Physiology and The Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX
| | - Mark D. McCauley
- Division of Cardiology, Department of Medicine, College of Medicine, University of Illinois at Chicago
- Department of Physiology and Biophysics and the Center for Cardiovascular Research, University of Illinois at Chicago
- Jesse Brown VA Medical Center, Chicago, IL
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Perike S, Gonzalez-Gonzalez FJ, Abu-Taha I, Damen FW, Lizama KS, Aboonabi A, Capote AE, Aguilar-Sanchez Y, Levin B, Han Z, Sridhar A, Grand J, Martin J, Akar JG, Warren CM, Solaro RJ, Ong SG, Darbar D, Goergen CJ, Wolska BM, Dobrev D, Wehrens XHT, McCauley MD. Myosin Light Chain Dephosphorylation by PPP1R12C Promotes Atrial Hypocontractility in Atrial Fibrillation. bioRxiv 2023:2023.04.19.537590. [PMID: 37131731 PMCID: PMC10153354 DOI: 10.1101/2023.04.19.537590] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Background Atrial fibrillation (AF), the most common sustained cardiac arrhythmia, increases thromboembolic stroke risk five-fold. Although atrial hypocontractility contributes to stroke risk in AF, the molecular mechanisms reducing myofilament contractile function remain unknown. We tested the hypothesis that increased expression of PPP1R12C, the PP1 regulatory subunit targeting atrial myosin light chain 2 (MLC2a), causes hypophosphorylation of MLC2a and results in atrial hypocontractility. Methods Right atrial appendage tissues were isolated from human AF patients versus sinus rhythm (SR) controls. Western blots, co-immunoprecipitation, and phosphorylation studies were performed to examine how the PP1c-PPP1R12C interaction causes MLC2a de-phosphorylation. In vitro studies of pharmacologic MRCK inhibitor (BDP5290) in atrial HL-1 cells were performed to evaluate PP1 holoenzyme activity on MLC2a. Cardiac-specific lentiviral PPP1R12C overexpression was performed in mice to evaluate atrial remodeling with atrial cell shortening assays, echocardiography, and AF inducibility with EP studies. Results In human patients with AF, PPP1R12C expression was increased two-fold versus SR controls ( P =2.0×10 -2 , n=12,12 in each group) with > 40% reduction in MLC2a phosphorylation ( P =1.4×10 -6 , n=12,12 in each group). PPP1R12C-PP1c binding and PPP1R12C-MLC2a binding were significantly increased in AF ( P =2.9×10 -2 and 6.7×10 -3 respectively, n=8,8 in each group). In vitro studies utilizing drug BDP5290, which inhibits T560-PPP1R12C phosphorylation, demonstrated increased PPP1R12C binding with both PP1c and MLC2a, and dephosphorylation of MLC2a. Lenti-12C mice demonstrated a 150% increase in LA size versus controls ( P =5.0×10 -6 , n=12,8,12), with reduced atrial strain and atrial ejection fraction. Pacing-induced AF in Lenti-12C mice was significantly higher than controls ( P =1.8×10 -2 and 4.1×10 -2 respectively, n= 6,6,5). Conclusions AF patients exhibit increased levels of PPP1R12C protein compared to controls. PPP1R12C overexpression in mice increases PP1c targeting to MLC2a and causes MLC2a dephosphorylation, which reduces atrial contractility and increases AF inducibility. These findings suggest that PP1 regulation of sarcomere function at MLC2a is a key determinant of atrial contractility in AF.
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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Langa P, Marszalek R, Warren CM, Chowdhury S, Halas M, Batra A, Rafael-Clyke K, Goldspink P, Solaro JR, Wolska B. Postnatal hypertrophic cardiomyopathy is associated with alterations in coronary flow, YAP signaling and vasculogenesis. J Mol Cell Cardiol 2022. [DOI: 10.1016/j.yjmcc.2022.08.044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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Solís C, Thompson WC, Peña JR, McDermott-Roe C, Langa P, Warren CM, Chrzanowska M, Wolska BM, Solaro RJ, Pieter Detombe, Goldspink PH. Mechano-growth factor E-domain modulates cardiac contractile function through 14-3-3 protein interactomes. Front Physiol 2022; 13:1028345. [PMID: 36467694 PMCID: PMC9709209 DOI: 10.3389/fphys.2022.1028345] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Accepted: 10/31/2022] [Indexed: 11/18/2022] Open
Abstract
In the heart, alternative splicing of the igf-I gene produces two isoforms: IGF-IEa and IGF-IEc, (Mechano-growth factor, MGF). The sequence divergence between their E-domain regions suggests differential isoform function. To define the biological actions of MGF's E-domain, we performed in silico analysis of the unique C-terminal sequence and identified a phosphorylation consensus site residing within a putative 14-3-3 binding motif. To test the functional significance of Ser 18 phosphorylation, phospho-mimetic (S/E18) and phospho-null (S/A18) peptides were delivered to mice at different doses for 2 weeks. Cardiovascular function was measured using echocardiography and a pressure-volume catheter. At the lowest (2.25 mg/kg/day) and highest (9 mg/kg/day) doses, the peptides produced a depression in systolic and diastolic parameters. However, at 4.5 mg/kg/day the peptides produced opposing effects on cardiac function. Fractional shortening analysis also showed a similar trend, but with no significant change in cardiac geometry. Microarray analysis discovered 21 genes (FDR p < 0.01), that were expressed accordant with the opposing effects on contractile function at 4.5 mg/kg/day, with the nuclear receptor subfamily 4 group A member 2 (Nr4a2) identified as a potential target of peptide regulation. Testing the regulation of the Nr4a family, showed the E-domain peptides modulate Nr4a gene expression following membrane depolarization with KCl in vitro. To determine the potential role of 14-3-3 proteins, we examined 14-3-3 isoform expression and distribution. 14-3-3γ localized to the myofilaments in neonatal cardiac myocytes, the cardiac myocytes and myofilament extracts from the adult heart. Thermal shift analysis of recombinant 14-3-3γ protein showed the S/A18 peptide destabilized 14-3-3γ folding. Also, the S/A18 peptide significantly inhibited 14-3-3γ's ability to interact with myosin binding protein C (MYPC3) and phospholamban (PLN) in heart lysates from dobutamine injected mice. Conversely, the S/E18 peptide showed no effect on 14-3-3γ stability, did not inhibit 14-3-3γ's interaction with PLN but did inhibit the interaction with MYPC3. Replacing the glutamic acid with a phosphate group on Ser 18 (pSer18), significantly increased 14-3-3γ protein stability. We conclude that the state of Ser 18 phosphorylation within the 14-3-3 binding motif of MGF's E-domain, modulates protein-protein interactions within the 14-3-3γ interactome, which includes proteins involved in the regulation of contractile function.
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Affiliation(s)
- Christopher Solís
- Department of Physiology and Biophysics, University of Illinois Chicago, Chicago, IL, United States
| | - Walter C. Thompson
- Department of Physiology and Biophysics, University of Illinois Chicago, Chicago, IL, United States
| | - James R. Peña
- Department of Physiology, Medical College of Wisconsin, Milwaukee, WI, United States
| | - Christopher McDermott-Roe
- Department of Medicine, and Department of Genetics, Perelman School of Medicine, Cardiovascular Institute, University of Pennsylvania, Philadelphia, PA, United States
| | - Paulina Langa
- Department of Physiology and Biophysics, University of Illinois Chicago, Chicago, IL, United States,Center for Cardiovascular Research, University of Illinois at Chicago, Chicago, IL, United States
| | - Chad M. Warren
- Department of Physiology and Biophysics, University of Illinois Chicago, Chicago, IL, United States,Center for Cardiovascular Research, University of Illinois at Chicago, Chicago, IL, United States
| | - Magdalena Chrzanowska
- Blood Research Institute, Versiti, Department of Pharmacology and Toxicology, Cardiovascular Center, Medical College of Wisconsin, Milwaukee, WI, United States
| | - Beata M. Wolska
- Center for Cardiovascular Research, University of Illinois at Chicago, Chicago, IL, United States,Department of Medicine, Division of Cardiology, University of Illinois at Chicago, Chicago, IL, United States
| | - R. John Solaro
- Department of Physiology and Biophysics, University of Illinois Chicago, Chicago, IL, United States,Department of Physiology, Medical College of Wisconsin, Milwaukee, WI, United States
| | - Pieter Detombe
- Department of Physiology and Biophysics, University of Illinois Chicago, Chicago, IL, United States,Phymedexp, Université de Montpellier, Inserm, CNRS, Montpellier, France
| | - Paul H. Goldspink
- Department of Physiology and Biophysics, University of Illinois Chicago, Chicago, IL, United States,Department of Physiology, Medical College of Wisconsin, Milwaukee, WI, United States,*Correspondence: Paul H. Goldspink,
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Solis C, DiNello E, Warren CM, Dittloff K, Solaro RJ, Russell B. Abstract P1058: Whole-cell Mechanical Loading And Unloading Triggers More Post-translational Modifications In α-actinin Than Myosin Activators And Inhibitors. Circ Res 2022. [DOI: 10.1161/res.131.suppl_1.p1058] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The hypothesis tested is that unloading of mechanical forces affects acetylation, ubiquitination, and phosphorylation of the actin-binding protein α-actinin located in the Z-disc. We applied targeted proteomics to interrogate the post-translational modification changes during loading and unloading. Cell morphology and post-translational modifications were determined in a mechanical intervention consisting of 1 Hz cyclic strain for 24 hr (loaded) followed by 6 hr rest (unloaded) of cultured neonatal rat ventricular myocytes (NRVMs). This was compared to a chemical intervention consisting of treating NRVMs with the myosin inhibitor Mavacamten (1 μM, 6hr) or activator Omecamtiv Mecarbil (0.5 μM, 6hr). Quantitative immunofluorescence showed both chemical and mechanical loading increased α-actinin content while Mavacamten decreased the α-actinin content. Mass spectrometry analysis of affinity-purified α-actinin revealed that the mechanical intervention led to increased levels of post-translational modifications compared with the chemical interventions. Specifically, α-actinin ubiquitination increased with mechanical loading-unloading; acetylation decreased with mechanical loading-unloading and increased with mechanical loading; and phosphorylation remained unchanged with mechanical loading-unloading but increased with mechanical loading. Fluorescence recovery after photobleaching (FRAP) experiments demonstrated that Mavacamten increased the dynamics of overexpressed YFP-tagged α-actinin and a GFP-tagged CapZ in NRVMs when compared to Omecamtiv Mecarbil treatments and controls. Overall, the results suggest a link between sarcomere homeostasis and mechanical forces via mechanisms involving acetylation, phosphorylation and ubiquitination of α-actinin and a second Z-disc protein, CapZ. These findings could have consequences for cardiac heart disease with abnormal sarcomeric proteostasis. Funded by NIH grants HL151825 (CS) and HL62426 (RJS, BR, and CMW).
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Halas M, Langa P, Warren CM, Goldspink PH, Wolska BM, Solaro RJ. Effects of Sarcomere Activators and Inhibitors Targeting Myosin Cross-Bridges on Ca2+-Activation of Mature and Immature Mouse Cardiac Myofilaments. Mol Pharmacol 2022; 101:286-299. [PMID: 35236770 PMCID: PMC9092471 DOI: 10.1124/molpharm.121.000420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Accepted: 02/16/2022] [Indexed: 11/22/2022] Open
Abstract
We tested the hypothesis that isoform shifts in sarcomeres of the immature heart modify the effect of cardiac myosin-directed sarcomere inhibitors and activators. Omecamtiv mecarbil (OM) activates tension and is in clinical trials for the treatment of adult acute and chronic heart failure. Mavacamten (Mava) inhibits tension and is in clinical trials to relieve hyper-contractility and outflow obstruction in advanced genetic hypertrophic cardiomyopathy (HCM) linked commonly to mutations in sarcomeric proteins. To address the effect of these agents in developing sarcomeres we isolated heart fiber bundles, extracted membranes with Triton X-100, and measured tension developed over a range of Ca2+ concentrations with and without OM or Mava treatment. We made measurements in fiber bundles from hearts of adult non-transgenic controls (NTG) expressing cardiac troponin I (cTnI), and from hearts of transgenic mice (TG-ssTnI) expressing the fetal/neonatal form, slow skeletal troponin I (ssTnI). We also compared fibers from 7+14-day-old NTG mice expressing ssTnI and cTnI. These studies were repeated with 7+14-day old transgenic mice (TG-cTnT-R92Q) expressing a mutant form of cardiac TnT (cTnT) linked to HCM. OM increased Ca2+-sensitivity and decreased cooperative activation in both ssTnI- and cTnI- regulated myofilaments with a similar effect reducing sub-maximal tension in immature and mature myofilaments. Although Mava decreased tension similarly in cTnI- and ssTnI-regulated myofilaments controlled either by cTnT or cTnT-R92Q, its effect involved a depressed Ca2+-sensitivity in the mature cTnT-R92-myofilaments. Our data demonstrate an influence of myosin and thin filament-associated proteins on the actions of myosin-directed agents such as OM and Mava. Significance Statement The effects of myosin-targeted activators and inhibitors on Ca2+-activated tension in developing cardiac sarcomeres presented here provide novel, ex-vivo evidence as to their actions in early-stage cardiac disorders. These studies advance understanding of the molecular mechanisms of these agents that is important in pre-clinical studies employing sarcomere Ca2+-response as a screening approach. The data also inform the use of commonly immature cardiac myocytes generated from human inducible pluripotent stem cells in screening for sarcomere activators and inhibitors.
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Affiliation(s)
- Monika Halas
- Physiology and Biophysics, University of Illinois at Chicago, United States
| | - Paulina Langa
- Physiology and Biophysics, University of Illinois at Chicago, United States
| | - Chad M Warren
- Physiology and Biophysics, University of Illinois at Chicago, United States
| | - Paul H Goldspink
- Physiology and Biophysics, University of Illinois at Chicago, United States
| | - Beata M Wolska
- Department of Medicine, University of Illinois at Chicago, United States
| | - R John Solaro
- Physiology and Biophysics, University of Illinois at Chicago, United States
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9
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Solís C, DiNello E, Warren CM, Dittloff K, Solaro RJ. Whole-cell mechanical loading and unloading triggers more post-translational modifications in Z-disc proteins than myosin activators and inhibitors. Biophys J 2022. [DOI: 10.1016/j.bpj.2021.11.597] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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10
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Capote AE, Batra A, Warren CM, Chowdhury SAK, Wolska BM, Solaro RJ, Rosas PC. B-arrestin-2 Signaling Is Important to Preserve Cardiac Function During Aging. Front Physiol 2021; 12:696852. [PMID: 34512376 PMCID: PMC8430342 DOI: 10.3389/fphys.2021.696852] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2021] [Accepted: 07/26/2021] [Indexed: 12/25/2022] Open
Abstract
Experiments reported here tested the hypothesis that β-arrestin-2 is an important element in the preservation of cardiac function during aging. We tested this hypothesis by aging β-arrestin-2 knock-out (KO) mice, and wild-type equivalent (WT) to 12–16months. We developed the rationale for these experiments on the basis that angiotensin II (ang II) signaling at ang II receptor type 1 (AT1R), which is a G-protein coupled receptor (GPCR) promotes both G-protein signaling as well as β-arrestin-2 signaling. β-arrestin-2 participates in GPCR desensitization, internalization, but also acts as a scaffold for adaptive signal transduction that may occur independently or in parallel to G-protein signaling. We have previously reported that biased ligands acting at the AT1R promote β-arrestin-2 signaling increasing cardiac contractility and reducing maladaptations in a mouse model of dilated cardiomyopathy. Although there is evidence that ang II induces maladaptive senescence in the cardiovascular system, a role for β-arrestin-2 signaling has not been studied in aging. By echocardiography, we found that compared to controls aged KO mice exhibited enlarged left atria and left ventricular diameters as well as depressed contractility parameters with preserved ejection fraction. Aged KO also exhibited depressed relaxation parameters when compared to WT controls at the same age. Moreover, cardiac dysfunction in aged KO mice was correlated with alterations in the phosphorylation of myofilament proteins, such as cardiac myosin binding protein-C, and myosin regulatory light chain. Our evidence provides novel insights into a role for β-arrestin-2 as an important signaling mechanism that preserves cardiac function during aging.
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Affiliation(s)
- Andrielle E Capote
- Department of Physiology & Biophysics, Center for Cardiovascular Research, University of Illinois at Chicago, Chicago, IL, United States
| | - Ashley Batra
- Department of Physiology & Biophysics, Center for Cardiovascular Research, University of Illinois at Chicago, Chicago, IL, United States
| | - Chad M Warren
- Department of Physiology & Biophysics, Center for Cardiovascular Research, University of Illinois at Chicago, Chicago, IL, United States
| | - Shamim A K Chowdhury
- Department of Physiology & Biophysics, Center for Cardiovascular Research, University of Illinois at Chicago, Chicago, IL, United States
| | - Beata M Wolska
- Department of Physiology & Biophysics, Center for Cardiovascular Research, University of Illinois at Chicago, Chicago, IL, United States.,Department of Medicine, Division of Cardiology, Center for Cardiovascular Research, University of Illinois at Chicago, Chicago, IL, United States
| | - R John Solaro
- Department of Physiology & Biophysics, Center for Cardiovascular Research, University of Illinois at Chicago, Chicago, IL, United States
| | - Paola C Rosas
- Department of Physiology & Biophysics, Center for Cardiovascular Research, University of Illinois at Chicago, Chicago, IL, United States
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11
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Solaro RJ, Rosas PC, Langa P, Warren CM, Wolska BM, Goldspink PH. Mechanisms of troponin release into serum in cardiac injury associated with COVID-19 patients. Int J Cardiol Cardiovasc Dis 2021; 1:41-47. [PMID: 34734211 PMCID: PMC8562719 DOI: 10.46439/cardiology.1.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Serum levels of thin filament proteins, cardiac troponin T (cTnT) and cardiac troponin I (cTnI) employing high sensitivity antibodies provide a state-of-the art determination of cardiac myocyte injury in COVID-19 patients. Although there is now sufficient evidence of the value of these determinations in patients infected with SARS-CoV-2, mechanisms of their release have not been considered in depth. We summarize the importance of these mechanisms with emphasis on their relation to prognosis, stratification, and treatment of COVID-19 patients. Apart from frank necrotic cell death, there are other mechanisms of myocyte injury leading to membrane fragility that provoke release of cTnT and cTnI. We discuss a rationale for understanding these mechanisms in COVID-19 patients with co-morbidities associated with myocyte injury such as heart failure, hypertension, arrythmias, diabetes, and inflammation. We describe how understanding these significant aspects of these mechanisms in the promotion of angiotensin signaling by SARS-CoV-2 can affect treatment options in the context of individualized therapies. Moreover, with likely omic data related to serum troponins and with the identification of elevations of serum troponins now more broadly detected employing high sensitivity antibodies, we think it is important to consider molecular mechanisms of elevations in serum troponin as an element in clinical decisions and as a critical aspect of development of new therapies.
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Affiliation(s)
- R. John Solaro
- Department of Physiology and Biophysics, University of Illinois at Chicago, Chicago, IL, USA
- Center for Cardiovascular Research, University of Illinois at Chicago, Chicago, IL, USA
| | - Paola C. Rosas
- Department of Physiology and Biophysics, University of Illinois at Chicago, Chicago, IL, USA
- Center for Cardiovascular Research, University of Illinois at Chicago, Chicago, IL, USA
| | - Paulina Langa
- Department of Physiology and Biophysics, University of Illinois at Chicago, Chicago, IL, USA
- Center for Cardiovascular Research, University of Illinois at Chicago, Chicago, IL, USA
| | - Chad M. Warren
- Department of Physiology and Biophysics, University of Illinois at Chicago, Chicago, IL, USA
- Center for Cardiovascular Research, University of Illinois at Chicago, Chicago, IL, USA
| | - Beata M. Wolska
- Department of Physiology and Biophysics, University of Illinois at Chicago, Chicago, IL, USA
- Center for Cardiovascular Research, University of Illinois at Chicago, Chicago, IL, USA
- Division of Cardiology, College of Medicine, University of Illinois at Chicago, Chicago, IL, USA
| | - Paul H. Goldspink
- Department of Physiology and Biophysics, University of Illinois at Chicago, Chicago, IL, USA
- Center for Cardiovascular Research, University of Illinois at Chicago, Chicago, IL, USA
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12
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Gonzalez-Gonzalez FJ, Srikanth P, Capote AE, Katherina M A, Levin B, Sridhar A, Jacob G, Martin J, Akar J, Warren CM, Solaro J, Darbar D, Goergen CJ, Wolska BM, Wehrens XH, McCauley M. Abstract P780: Myosin Light Chain Dephosphorylation by Ppp1r12c Promotes Atrial Hypocontractility in Atrial Fibrillation. Stroke 2021. [DOI: 10.1161/str.52.suppl_1.p780] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Atrial fibrillation (AF) is the most common sustained arrhythmia, with an estimated prevalence in the U.S.of 6.1 million. AF increases the risk of a thromboembolic stroke in five-fold. Although atrial hypocontractility contributes to stroke risk in AF, the molecular mechanisms reducing myofilament contractile function in AF remains unknown. We have recently identified protein phosphatase 1 subunit 12c (PPP1R12C) as a key molecule targeting myosin light-chain phosphorylation in AF.
Objective:
We hypothesize that the overexpression of PPP1R12C causes hypophosphorylation of atrial myosin light-chain 2 (MLC2a), thereby decreasing atrial contractility in AF.
Methods and Results:
Left and right atrial appendage tissues were isolated from AF patients versus sinus rhythm (SR). To evaluate the role of the PP1c-PPP1R12C interaction in MLC2a de-phosphorylation, we utilized Western blots, co-immunoprecipitation, and phosphorylation assays. In patients with AF, PPP1R12C expression was increased 3.5-fold versus SR controls with an 88% reduction in MLC2a phosphorylation. PPP1R12C-PP1c binding and PPP1R12C-MLC2a binding were significantly increased in AF. In vitro studies of either pharmacologic (BDP5290) or genetic (T560A), PPP1R12C activation demonstrated increased PPP1R12C binding with both PP1c and MLC2a, and dephosphorylation of MLC2a. Additionally, to evaluate the role of PPP1R12C expression in cardiac function, mice with lentiviral cardiac-specific overexpression of PPP1R12C (Lenti-12C) were evaluated for atrial contractility using echocardiography, versus wild-type and Lenti-controls. Lenti-12C mice demonstrated a 150% increase in left atrium size versus controls, with reduced atrial strain and atrial ejection fraction. Also, programmed electrical stimulation was performed to evaluate AF inducibility in vivo. Pacing-induced AF in Lenti-12C mice was significantly higher than controls.
Conclusion:
The overexpression of PPP1R12C increases PP1c targeting to MLC2a and provokes dephosphorylation, associated with a reduction in atrial contractility and an increase in AF inducibility. All these discoveries suggest that PP1 regulation of sarcomere function at MLC2a is a main regulator of atrial contractility in AF.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | | | | | | | - Xander H Wehrens
- Cardiovascular Rsch Institute, Baylor College of Medicine, Houston, TX
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13
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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14
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Batra A, Warren CM, Ke Y, McCann M, Halas M, Capote AE, Liew CW, Solaro RJ, Rosas PC. Deletion of P21-activated kinase-1 induces age-dependent increased visceral adiposity and cardiac dysfunction in female mice. Mol Cell Biochem 2021; 476:1337-1349. [PMID: 33389497 DOI: 10.1007/s11010-020-03993-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2020] [Accepted: 11/16/2020] [Indexed: 12/12/2022]
Abstract
It is known that there is an age-related progression in diastolic dysfunction, especially prevalent in postmenopausal women, who develop heart failure with preserved ejection fraction (HFpEF, EF > 50%). Mechanisms and therapies are poorly understood, but there are strong correlations between obesity and HFpEF. We have tested the hypothesis that P21-activated kinase-1 (PAK1) preserves cardiac function and adipose tissue homeostasis during aging in female mice. Previous demonstrations in male mice by our lab that PAK1 activity confers cardio-protection against different stresses formed the rationale for this hypothesis. Our studies compared young (3-6 months) and middle-aged (12-15 months) female and male PAK1 knock-out mice (PAK1-/-) and wild-type (WT) equivalent. Female WT mice exhibited increased cardiac PAK1 abundance during aging. By echocardiography, compared to young WT female mice, middle-aged WT female mice showed enlargement of the left atrium as well as thickening of posterior wall and increased left ventricular mass; however, all contraction and relaxation parameters were preserved during aging. Compared to WT controls, middle-aged PAK1-/- female mice demonstrated worsening of cardiac function involving a greater enlargement of the left atrium, ventricular hypertrophy, and diastolic dysfunction. Moreover, with aging PAK1-/- female mice, unlike male PAK1-/- mice, exhibited increased adiposity with increased accumulation of visceral adipose tissue. Our data provide evidence for the significance of PAK1 signaling as an element in the preservation of cardiac function and adipose tissue homeostasis in females during aging.
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Affiliation(s)
- Ashley Batra
- Department of Physiology & Biophysics, Center for Cardiovascular Research, University of Illinois at Chicago, Chicago, IL, USA
| | - Chad M Warren
- Department of Physiology & Biophysics, Center for Cardiovascular Research, University of Illinois at Chicago, Chicago, IL, USA
| | - Yunbo Ke
- Department of Anesthesiology, School of Medicine, University of Maryland, Baltimore, MD, USA
| | - Maximilian McCann
- Department of Physiology & Biophysics, Center for Cardiovascular Research, University of Illinois at Chicago, Chicago, IL, USA
| | - Monika Halas
- Department of Physiology & Biophysics, Center for Cardiovascular Research, University of Illinois at Chicago, Chicago, IL, USA
| | - Andrielle E Capote
- Department of Physiology & Biophysics, Center for Cardiovascular Research, University of Illinois at Chicago, Chicago, IL, USA
| | - Chong Wee Liew
- Department of Physiology & Biophysics, Center for Cardiovascular Research, University of Illinois at Chicago, Chicago, IL, USA
| | - R John Solaro
- Department of Physiology & Biophysics, Center for Cardiovascular Research, University of Illinois at Chicago, Chicago, IL, USA
| | - Paola C Rosas
- Department of Physiology & Biophysics, Center for Cardiovascular Research, University of Illinois at Chicago, Chicago, IL, USA.
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15
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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. J Cell Signal 2021; 2:162-171. [PMID: 34541579 PMCID: PMC8444995] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [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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16
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Solís C, Solaro RJ, Warren CM, Russell B. Abstract 416: Sarcomere Disassembly After Unloading is Regulated by Ubiquitination and Acetylation of Capz and α-actinin. Circ Res 2020. [DOI: 10.1161/res.127.suppl_1.416] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Cardiac function mainly depends on the total myocyte mass in the ventricles. Assembly and disassembly of sarcomeres occurs to adjust this mass to altered mechanical demand. In the heart, hypertrophic cardiomyopathy results from myofibrillar assembly controlled by post-translational modification of proteins directed by signaling pathways. More is known about assembly on loading than disassembly on unloading. Here, the hypothesis tested is that unloading of mechanical forces affects acetylation (Ac) and ubiquitination (Ub) of the actin-binding proteins, α-actinin and CapZ. Omecamtiv mecarbil (0.5 μM) and mavacamten (1 μM) were used to increase (load) and decrease (unload) cardiomyocyte tension, respectively, via their action on myosin ATPase. Mavacamten decreased myocyte contractility in rat ventricular myocytes (NRVMs) and caused significant sarcomere disassembly by 6 h and 70% atrophy by 24 h. Assembly was preserved with omecamtiv mecarbil (0.5 μM) over the 24 h time period. Post-translational modification was determined in loaded and unloaded NRVMs at 6 h of drug treatment. Bottom-up mass spectrometry analysis showed single residues in α-actinin and CapZ that were acetylated or ubiquitinated. Acetylation levels appeared to increase in the mavacamten-treated samples while these levels are preserved in untreated and omecamtiv mecarbil-treated samples. Ac and Ub in the Z-discs were quantified on immunofluorescent images. The Z-discs colocalized oligo-Ub (K-48 oligo-Ub linkage) and Ac in untreated samples; this Z-disc localization of Ub and Ac was diminished with unloading. Fluorescence recovery after photobleaching (FRAP) measurements of the dynamics of α-actinin and CapZ after reduced cell tension with mavacamten (1 μM) and omecamtiv mercabil (0.5 μM) are ongoing. Overall, results suggest sarcomere assembly is regulated by mechanical forces through a mechanism involving Ac and Ub of myofibrillar proteins. These findings could have consequences for cardiac heart disease with abnormal sarcomeric proteostasis.
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17
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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18
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Goldspink P, Martin JL, Warren CM, Thompson W, Levi-D'Ancona E, de Tombe PP. Deamidation of Asparagine14 Prevents Serine15 Phosphorylation of Human Cardiac MLC2V. Biophys J 2020. [DOI: 10.1016/j.bpj.2019.11.3211] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
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19
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Ryba DM, Warren CM, Karam CN, Davis RT, Chowdhury SAK, Alvarez MG, McCann M, Liew CW, Wieczorek DF, Varga P, Solaro RJ, Wolska BM. Sphingosine-1-Phosphate Receptor Modulator, FTY720, Improves Diastolic Dysfunction and Partially Reverses Atrial Remodeling in a Tm-E180G Mouse Model Linked to Hypertrophic Cardiomyopathy. Circ Heart Fail 2019; 12:e005835. [PMID: 31684756 DOI: 10.1161/circheartfailure.118.005835] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
BACKGROUND Hypertrophic cardiomyopathy (HCM) is a genetic cardiovascular disorder, primarily involving mutations in sarcomeric proteins. HCM patients present with hypertrophy, diastolic dysfunction, and fibrosis, but there is no specific treatment. The sphingosine-1-phosphate receptor modulator, FTY720/fingolimod, is approved for treatment of multiple sclerosis. We hypothesize that modulation of the sphingosine-1-phosphate receptor by FTY720 would be of therapeutic benefit in sarcomere-linked HCM. METHODS We treated mice with an HCM-linked mutation in tropomyosin (Tm-E180G) and nontransgenic littermates with FTY720 or vehicle for 6 weeks. Compared with vehicle-treated, FTY720-treated Tm-E180G mice had a significant reduction in left atrial size (1.99±0.19 [n=7] versus 2.70±0.44 [n=6] mm; P<0.001) and improvement in diastolic function (E/A ratio: 2.69±0.38 [n=7] versus 5.34±1.19 [n=6]; P=0.004) as assessed by echocardiography. RESULTS Pressure-volume relations revealed significant improvements in the end-diastolic pressure volume relationship, relaxation kinetics, preload recruitable stroke work, and ejection fraction. Detergent-extracted fiber bundles revealed a significant decrease in myofilament Ca2+-responsiveness (pCa50=6.15±0.11 [n=13] versus 6.24±0.06 [n=14]; P=0.041). We attributed these improvements to a downregulation of S-glutathionylation of cardiac myosin binding protein-C in FTY720-treated Tm-E180G mice and reduction in oxidative stress by downregulation of NADPH oxidases with no changes in fibrosis. CONCLUSIONS This is the first demonstration that modulation of S1PR results in decreased myofilament-Ca2+-responsiveness and improved diastolic function in HCM. We associated these changes with decreased oxidative modification of myofilament proteins via downregulation of NOX2. Our data support the hypothesis that modification of sphingolipid signaling may be a novel therapeutic approach in HCM.
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Affiliation(s)
- David M Ryba
- Department of Physiology and Biophysics and the Center for Cardiovascular Research, College of Medicine, University of Illinois at Chicago (D.M.R., C.M.W., C.N.K., R.T.D., S.A.K.C., M.G.A., M.M., C.W.L., R.J.S., B.M.W.)
| | - Chad M Warren
- Department of Physiology and Biophysics and the Center for Cardiovascular Research, College of Medicine, University of Illinois at Chicago (D.M.R., C.M.W., C.N.K., R.T.D., S.A.K.C., M.G.A., M.M., C.W.L., R.J.S., B.M.W.)
| | - Chehade N Karam
- Department of Physiology and Biophysics and the Center for Cardiovascular Research, College of Medicine, University of Illinois at Chicago (D.M.R., C.M.W., C.N.K., R.T.D., S.A.K.C., M.G.A., M.M., C.W.L., R.J.S., B.M.W.)
| | - Robert T Davis
- Department of Physiology and Biophysics and the Center for Cardiovascular Research, College of Medicine, University of Illinois at Chicago (D.M.R., C.M.W., C.N.K., R.T.D., S.A.K.C., M.G.A., M.M., C.W.L., R.J.S., B.M.W.)
| | - Shamim A K Chowdhury
- Department of Physiology and Biophysics and the Center for Cardiovascular Research, College of Medicine, University of Illinois at Chicago (D.M.R., C.M.W., C.N.K., R.T.D., S.A.K.C., M.G.A., M.M., C.W.L., R.J.S., B.M.W.)
| | - Manuel G Alvarez
- Department of Physiology and Biophysics and the Center for Cardiovascular Research, College of Medicine, University of Illinois at Chicago (D.M.R., C.M.W., C.N.K., R.T.D., S.A.K.C., M.G.A., M.M., C.W.L., R.J.S., B.M.W.)
| | - Maximilian McCann
- Department of Physiology and Biophysics and the Center for Cardiovascular Research, College of Medicine, University of Illinois at Chicago (D.M.R., C.M.W., C.N.K., R.T.D., S.A.K.C., M.G.A., M.M., C.W.L., R.J.S., B.M.W.)
| | - Chong Wee Liew
- Department of Physiology and Biophysics and the Center for Cardiovascular Research, College of Medicine, University of Illinois at Chicago (D.M.R., C.M.W., C.N.K., R.T.D., S.A.K.C., M.G.A., M.M., C.W.L., R.J.S., B.M.W.)
| | - David F Wieczorek
- Department of Molecular Genetics, Biochemistry, and Microbiology, University of Cincinnati College of Medicine, OH (D.F.W.)
| | - Peter Varga
- Department of Pediatrics, Section of Cardiology, University of Illinois at Chicago (P.V.)
| | - R John Solaro
- Department of Physiology and Biophysics and the Center for Cardiovascular Research, College of Medicine, University of Illinois at Chicago (D.M.R., C.M.W., C.N.K., R.T.D., S.A.K.C., M.G.A., M.M., C.W.L., R.J.S., B.M.W.)
| | - Beata M Wolska
- Department of Physiology and Biophysics and the Center for Cardiovascular Research, College of Medicine, University of Illinois at Chicago (D.M.R., C.M.W., C.N.K., R.T.D., S.A.K.C., M.G.A., M.M., C.W.L., R.J.S., B.M.W.).,Department of Medicine, Division of Cardiology, University of Illinois at Chicago, IL (B.M.W.)
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20
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Rosas PC, Warren CM, Batra A, Creed H, Solaro RJ, Tong CW. Abstract 621: Cardiac Myosin Binding Protein-C Phosphorylation in Ser-273 and Ser-282 is Critical to Maintain Cardiac Function During Aging. Circ Res 2019. [DOI: 10.1161/res.125.suppl_1.621] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background/hypothesis:
Heart failure (HF) afflicts 6.2M Americans as of 2019 and its prevalence is expected to increase due to a growing aging population. HF progression involves depression in contractility and relaxation, which are strongly controlled by phosphorylation of cardiac myosin binding protein-C (cMyBP-C). We hypothesize that phosphorylated cMyBP-C supports normal heart function during aging.
Methods:
We aged mouse models of cMyBP-C de-phosphorylation mimetic (t3SA: S273A/S282A/S302A mutations), phosphorylation mimetic (t3SD: S273D/S282D/S302D mutations) and WT equivalent expressed onto cMyBP-C(-/-) background (tWT).
Results:
Western blotting (N=16, 2-24 months) showed that cMyBP-C phosphorylation decreases with aging at S273 and S282, showing strong Pearson correlations with age (see figure; S273P r= -0.931, p<0.0001; S282P r=-0.868, p<0.00001). Simultaneous force and [Ca
2+
]
i
measurements on intact papillary muscles showed that phosphorylation-mimetic t3SD has greatest dFR=(-dF/dt)min/(+dF/dt)max, signifying better lusitropy with similar calcium decay rate constant (k
Ca
) as others. Echocardiography at 3, 12, 15, 18 months showed that t3SD has preserved ejection fraction, faster peak myocardial relaxation velocity e’ and preserved posterior ventricular wall thickness with aging. Moreover, t3SD demonstrated superior 600-days survival than others (t3SD 87.5% n=96; tWT 69.3% n=122; t3SA 53.2% n=97; overall LogRank p=0.0002244).
Conclusions:
De-phosphorylation of cMyBP-C at S273 and S282 contributes to worsening of cardiac function with aging. Conversely, phosphorylated cMyBP-C mitigates aging-related cardiac dysfunction.
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21
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Olver TD, Edwards JC, Jurrissen TJ, Veteto AB, Jones JL, Gao C, Rau C, Warren CM, Klutho PJ, Alex L, Ferreira-Nichols SC, Ivey JR, Thorne PK, McDonald KS, Krenz M, Baines CP, Solaro RJ, Wang Y, Ford DA, Domeier TL, Padilla J, Rector RS, Emter CA. Western Diet-Fed, Aortic-Banded Ossabaw Swine: A Preclinical Model of Cardio-Metabolic Heart Failure. JACC Basic Transl Sci 2019; 4:404-421. [PMID: 31312763 PMCID: PMC6610000 DOI: 10.1016/j.jacbts.2019.02.004] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Revised: 02/13/2019] [Accepted: 02/21/2019] [Indexed: 12/12/2022]
Abstract
The development of new treatments for heart failure lack animal models that encompass the increasingly heterogeneous disease profile of this patient population. This report provides evidence supporting the hypothesis that Western Diet-fed, aortic-banded Ossabaw swine display an integrated physiological, morphological, and genetic phenotype evocative of cardio-metabolic heart failure. This new preclinical animal model displays a distinctive constellation of findings that are conceivably useful to extending the understanding of how pre-existing cardio-metabolic syndrome can contribute to developing HF.
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Key Words
- AB, aortic-banded
- CON, control
- EDPVR, end-diastolic pressure−volume relationship
- EF, ejection fraction
- HF, heart failure
- HFpEF, heart failure with preserved ejection fraction
- HFrEF, heart failure with reduced ejection fraction
- IL1RL1, interleukin 1 receptor-like 1
- LV, left ventricle
- NF, nuclear factor
- PTX3, pentraxin-3
- WD, Western Diet
- cardio-metabolic disease
- heart failure
- integrative pathophysiology
- preclinical model of cardiovascular disease
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Affiliation(s)
- T. Dylan Olver
- Department of Biomedical Science, University of Missouri-Columbia, Columbia, Missouri
| | - Jenna C. Edwards
- Department of Biomedical Science, University of Missouri-Columbia, Columbia, Missouri
| | - Thomas J. Jurrissen
- Department of Nutrition and Exercise Physiology, University of Missouri-Columbia, Columbia, Missouri
| | - Adam B. Veteto
- Department of Medical Pharmacology and Physiology, University of Missouri-Columbia, Columbia, Missouri
| | - John L. Jones
- Department of Medical Pharmacology and Physiology, University of Missouri-Columbia, Columbia, Missouri
| | - Chen Gao
- David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California
| | - Christoph Rau
- David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California
| | - Chad M. Warren
- Department of Physiology and Biophysics, Center for Cardiovascular Research, University of Illinois at Chicago, Chicago, Illinois
| | - Paula J. Klutho
- Dalton Cardiovascular Research Center, University of Missouri-Columbia, Columbia, Missouri
| | - Linda Alex
- Dalton Cardiovascular Research Center, University of Missouri-Columbia, Columbia, Missouri
| | | | - Jan R. Ivey
- Department of Biomedical Science, University of Missouri-Columbia, Columbia, Missouri
| | - Pamela K. Thorne
- Department of Biomedical Science, University of Missouri-Columbia, Columbia, Missouri
| | - Kerry S. McDonald
- Department of Medical Pharmacology and Physiology, University of Missouri-Columbia, Columbia, Missouri
| | - Maike Krenz
- Department of Medical Pharmacology and Physiology, University of Missouri-Columbia, Columbia, Missouri
- Dalton Cardiovascular Research Center, University of Missouri-Columbia, Columbia, Missouri
| | - Christopher P. Baines
- Department of Biomedical Science, University of Missouri-Columbia, Columbia, Missouri
- Department of Medical Pharmacology and Physiology, University of Missouri-Columbia, Columbia, Missouri
- Dalton Cardiovascular Research Center, University of Missouri-Columbia, Columbia, Missouri
| | - R. John Solaro
- Department of Physiology and Biophysics, Center for Cardiovascular Research, University of Illinois at Chicago, Chicago, Illinois
| | - Yibin Wang
- David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California
| | - David A. Ford
- Department of Biochemistry and Molecular Biology and Center for Cardiovascular Research, Saint Louis University- School of Medicine, St. Louis, Missouri
| | - Timothy L. Domeier
- Department of Medical Pharmacology and Physiology, University of Missouri-Columbia, Columbia, Missouri
| | - Jaume Padilla
- Department of Nutrition and Exercise Physiology, University of Missouri-Columbia, Columbia, Missouri
- Dalton Cardiovascular Research Center, University of Missouri-Columbia, Columbia, Missouri
- Department of Child Health, University of Missouri-Columbia, Columbia, Missouri
| | - R. Scott Rector
- Department of Nutrition and Exercise Physiology, University of Missouri-Columbia, Columbia, Missouri
- Department of Medicine – University of Missouri-Columbia, Columbia, Missouri
- Research Service, Harry S Truman Memorial VA Hospital, University of Missouri-Columbia, Columbia, Missouri
| | - Craig A. Emter
- Department of Biomedical Science, University of Missouri-Columbia, Columbia, Missouri
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22
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Abstract
Very large proteins (subunit sizes, >200 kDa) are difficult to electrophoretically separate on polyacrylamide gels. A SDS vertical agarose gel system has been developed that has vastly improved resolving power for very large proteins. Proteins with molecular masses between 200 and 4000 kDa can be clearly separated. Inclusion of a reducing agent in the upper reservoir buffer and use of a large pore-sized agarose have been found to be key technical procedures for obtaining optimum protein migration and resolution.
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Affiliation(s)
- Marion L Greaser
- Muscle Biology Laboratory, University of Wisconsin-Madison, Madison, WI, USA.
| | - Chad M Warren
- Department of Physiology and Biophysics and Center for Cardiovascular Research, University of Illinois at Chicago, Chicago, IL, USA
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23
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Rajan S, Jagatheesan G, Petrashevskaya N, Biesiadecki BJ, Warren CM, Riddle T, Liggett S, Wolska BM, Solaro RJ, Wieczorek DF. Tropomyosin pseudo-phosphorylation results in dilated cardiomyopathy. J Biol Chem 2018; 294:2913-2923. [PMID: 30567734 DOI: 10.1074/jbc.ra118.004879] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Revised: 12/10/2018] [Indexed: 12/18/2022] Open
Abstract
Phosphorylation of cardiac sarcomeric proteins plays a major role in the regulation of the physiological performance of the heart. Phosphorylation of thin filament proteins, such as troponin I and T, dramatically affects calcium sensitivity of the myofiber and systolic and diastolic functions. Phosphorylation of the regulatory protein tropomyosin (Tpm) results in altered biochemical properties of contraction; however, little is known about the physiological effect of Tpm phosphorylation on cardiac function. To address the in vivo significance of Tpm phosphorylation, here we generated transgenic mouse lines having a phosphomimetic substitution in the phosphorylation site of α-Tpm (S283D). High expression of Tpm S283D variant in one transgenic mouse line resulted in an increased heart:body weight ratio, coupled with a severe dilated cardiomyopathic phenotype resulting in death within 1 month of birth. Moderate Tpm S283D mice expression in other lines caused mild myocyte hypertrophy and fibrosis, did not affect lifespan, and was coupled with decreased expression of extracellular signal-regulated kinase 1/2 kinase signaling. Physiological analysis revealed that the transgenic mice exhibit impaired diastolic function, without changes in systolic performance. Surprisingly, we observed no alterations in calcium sensitivity of the myofibers, cooperativity, or calcium-ATPase activity in the myofibers. Our experiments also disclosed that casein kinase 2 plays an integral role in Tpm phosphorylation. In summary, increased expression of pseudo-phosphorylated Tpm impairs diastolic function in the intact heart, without altering calcium sensitivity or cooperativity of myofibers. Our findings provide the first extensive in vivo assessment of Tpm phosphorylation in the heart and its functional role in cardiac performance.
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Affiliation(s)
- Sudarsan Rajan
- From the Department of Molecular Genetics, Biochemistry, and Microbiology, University of Cincinnati College of Medicine, Cincinnati, Ohio 45267
| | - Ganapathy Jagatheesan
- From the Department of Molecular Genetics, Biochemistry, and Microbiology, University of Cincinnati College of Medicine, Cincinnati, Ohio 45267
| | | | - Brandon J Biesiadecki
- the Department of Physiology and Biophysics, University of Illinois, Chicago College of Medicine, Chicago, Illinois 60612.,the Department of Physiology and Cell Biology and the Davis Heart and Lung Research Institute, Ohio State University, Columbus, Ohio 43210, and
| | - Chad M Warren
- the Department of Physiology and Biophysics, University of Illinois, Chicago College of Medicine, Chicago, Illinois 60612
| | - Tara Riddle
- From the Department of Molecular Genetics, Biochemistry, and Microbiology, University of Cincinnati College of Medicine, Cincinnati, Ohio 45267
| | - Stephen Liggett
- the Department of Medicine, University of Maryland, Baltimore, Maryland 21201
| | - Beata M Wolska
- the Department of Physiology and Biophysics, University of Illinois, Chicago College of Medicine, Chicago, Illinois 60612.,the Division of Cardiology, Department of Medicine, University of Illinois, Chicago, Illinois 60612
| | - R John Solaro
- the Department of Physiology and Biophysics, University of Illinois, Chicago College of Medicine, Chicago, Illinois 60612
| | - David F Wieczorek
- From the Department of Molecular Genetics, Biochemistry, and Microbiology, University of Cincinnati College of Medicine, Cincinnati, Ohio 45267,
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24
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Warren CM, Tona KD, Ouwerkerk L, van Paridon J, Poletiek F, van Steenbergen H, Bosch JA, Nieuwenhuis S. The neuromodulatory and hormonal effects of transcutaneous vagus nerve stimulation as evidenced by salivary alpha amylase, salivary cortisol, pupil diameter, and the P3 event-related potential. Brain Stimul 2018; 12:635-642. [PMID: 30591360 DOI: 10.1016/j.brs.2018.12.224] [Citation(s) in RCA: 80] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2018] [Revised: 12/07/2018] [Accepted: 12/12/2018] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Transcutaneous vagus nerve stimulation (tVNS) is a new, non-invasive technique being investigated as an intervention for a variety of clinical disorders, including epilepsy and depression. It is thought to exert its therapeutic effect by increasing central norepinephrine (NE) activity, but the evidence supporting this notion is limited. OBJECTIVE In order to test for an impact of tVNS on psychophysiological and hormonal indices of noradrenergic function, we applied tVNS in concert with assessment of salivary alpha amylase (SAA) and cortisol, pupil size, and electroencephalograph (EEG) recordings. METHODS Across three experiments, we applied real and sham tVNS to 61 healthy participants while they performed a set of simple stimulus-discrimination tasks. Before and after the task, as well as during one break, participants provided saliva samples and had their pupil size recorded. EEG was recorded throughout the task. The target for tVNS was the cymba conchae, which is heavily innervated by the auricular branch of the vagus nerve. Sham stimulation was applied to the ear lobe. RESULTS P3 amplitude was not affected by tVNS (Experiment 1A: N = 24; Experiment 1B: N = 20; Bayes factor supporting null model = 4.53), nor was pupil size (Experiment 2: N = 16; interaction of treatment and time: p = .79). However, tVNS increased SAA (Experiments 1A and 2: N = 25) and attenuated the decline of salivary cortisol compared to sham (Experiment 2: N = 17), as indicated by significant interactions involving treatment and time (p = .023 and p = .040, respectively). CONCLUSION These findings suggest that tVNS modulates hormonal indices but not psychophysiological indices of noradrenergic function.
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Affiliation(s)
- C M Warren
- Institute of Psychology, Leiden University, Leiden, 2333, AK, Netherlands; Leiden Institute for Brain and Cognition, Leiden University, Leiden, 2300, RC, Netherlands.
| | - K D Tona
- Institute of Psychology, Leiden University, Leiden, 2333, AK, Netherlands; Leiden Institute for Brain and Cognition, Leiden University, Leiden, 2300, RC, Netherlands
| | - L Ouwerkerk
- Institute of Psychology, Leiden University, Leiden, 2333, AK, Netherlands
| | - J van Paridon
- Institute of Psychology, Leiden University, Leiden, 2333, AK, Netherlands; Max Planck Institute of Psycholinguistics, Nijmegen, 6525, XD, Netherlands
| | - F Poletiek
- Institute of Psychology, Leiden University, Leiden, 2333, AK, Netherlands; Max Planck Institute of Psycholinguistics, Nijmegen, 6525, XD, Netherlands
| | - Henk van Steenbergen
- Institute of Psychology, Leiden University, Leiden, 2333, AK, Netherlands; Leiden Institute for Brain and Cognition, Leiden University, Leiden, 2300, RC, Netherlands
| | - J A Bosch
- Department of Clinical Psychology, University of Amsterdam, Amsterdam, 1018, XA, Netherlands; Mannheim Institute of Public Health, Heidelberg University, Mannheim, 68167, Germany
| | - S Nieuwenhuis
- Institute of Psychology, Leiden University, Leiden, 2333, AK, Netherlands; Leiden Institute for Brain and Cognition, Leiden University, Leiden, 2300, RC, Netherlands
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25
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Kobayashi M, Ramirez BE, Warren CM. Interplay of actin, ADP and Mg 2+ interactions with striated muscle myosin: Implications of their roles in ATPase. Arch Biochem Biophys 2018; 662:101-110. [PMID: 30529103 DOI: 10.1016/j.abb.2018.12.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Revised: 11/25/2018] [Accepted: 12/03/2018] [Indexed: 12/15/2022]
Abstract
The effects of Mg2+ on the interaction between ADP, a product of the ATPase reaction, and striated muscle myosin-subfragment 1 (S1) were investigated with both functional and spectroscopic methods. Mg2+ inhibited striated muscle myosin ATPase in the presence of F-actin. Significant effects of Mg2+ were observed in both rate constants of NOE build-up and maximal intensities in WaterLOGSY NMR experiments as F-actin concentration increased. In the absence of F-actin, myosin S1 with Mg2+ bound to a fluorescent ADP analog about five-times tighter than without Mg2+. In the presence of F-actin, the affinity of myosin S1 toward the ADP analog significantly decreased both with and without Mg2+. The equilibrium titration of myosin-S1 into F-actin revealed that in the presence of ADP the apparent dissociation constant (Kd) without Mg2+ was more than five-fold smaller than with Mg2+. Further, we examined effects of F-actin, ADP and Mg2+ binding to myosin on the tertiary structure of myosin-S1 using near UV circular dichroism (CD) spectroscopy. Both in the presence and absence of ADP, there was a Mg2+-dependent difference in the near UV CD spectra of actomyosin. Our results show that Mg2+ affects myosin-ADP and actin-myosin interactions which may be reflected in myosin ATPase activity.
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Affiliation(s)
- Minae Kobayashi
- Department of Physiology and Biophysics, University of Illinois at Chicago, Chicago, IL, USA; Center for Cardiovascular Research, University of Illinois at Chicago, Chicago, IL, USA.
| | - Benjamin E Ramirez
- Department of Biochemistry and Molecular Genetics, University of Illinois at Chicago, Chicago, IL, USA
| | - Chad M Warren
- Department of Physiology and Biophysics, University of Illinois at Chicago, Chicago, IL, USA; Center for Cardiovascular Research, University of Illinois at Chicago, Chicago, IL, USA
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26
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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27
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Ryba DM, Warren CM, Karam CN, Davis RT, Chowdhury SA, Alvarez MG, Wieczorek DF, John Solaro R, Wolska BM. The Sphingosine-1-Phosphate Receptor Modulator, FTY720, Reverses Diastolic Dysfunction and Hypertrophy in Hypertrophic Cardiomyopathy. J Mol Cell Cardiol 2017. [DOI: 10.1016/j.yjmcc.2017.07.079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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28
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Ryba DM, Warren CM, Karam CN, Davis RT, Chowdhury SAK, Alvarez MG, Wieczorek DF, Solaro RJ, Wolska BM. The Sphingosine‐1‐Phosphate Analog, FTY720, Reverses Diastolic Dysfunction and Hypertrophy in Familial Hypertrophic Cardiomyopathy. FASEB J 2017. [DOI: 10.1096/fasebj.31.1_supplement.687.5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- David M Ryba
- Department of Physiology and Biophysics and Center for Cardiovascular ResearchUniversity of Illinois at ChicagoChicagoIL
| | - Chad M Warren
- Department of Physiology and Biophysics and Center for Cardiovascular ResearchUniversity of Illinois at ChicagoChicagoIL
| | - Chehade N Karam
- Department of Physiology and Biophysics and Center for Cardiovascular ResearchUniversity of Illinois at ChicagoChicagoIL
| | - Robert T. Davis
- Department of Physiology and Biophysics and Center for Cardiovascular ResearchUniversity of Illinois at ChicagoChicagoIL
| | - Shamim A. K. Chowdhury
- Department of Physiology and Biophysics and Center for Cardiovascular ResearchUniversity of Illinois at ChicagoChicagoIL
| | - Manuel G. Alvarez
- Department of Physiology and Biophysics and Center for Cardiovascular ResearchUniversity of Illinois at ChicagoChicagoIL
| | - David F Wieczorek
- Molecular Genetics, Biochemistry and MicrobiologyUniversity of CincinnatiCincinnatiOH
| | - R. John Solaro
- Department of Physiology and Biophysics and Center for Cardiovascular ResearchUniversity of Illinois at ChicagoChicagoIL
| | - Beata M. Wolska
- Department of Physiology and Biophysics and Center for Cardiovascular ResearchUniversity of Illinois at ChicagoChicagoIL
- Division of CardiologyUniversity of Illinois at ChicagoChicagoIL
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29
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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Lin YH, Warren CM, Li J, McKinsey TA, Russell B. Myofibril growth during cardiac hypertrophy is regulated through dual phosphorylation and acetylation of the actin capping protein CapZ. Cell Signal 2016; 28:1015-24. [PMID: 27185186 DOI: 10.1016/j.cellsig.2016.05.011] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2016] [Revised: 05/11/2016] [Accepted: 05/12/2016] [Indexed: 01/08/2023]
Abstract
The mechanotransduction signaling pathways initiated in heart muscle by increased mechanical loading are known to lead to long-term transcriptional changes and hypertrophy, but the rapid events for adaptation at the sarcomeric level are not fully understood. The goal of this study was to test the hypothesis that actin filament assembly during cardiomyocyte growth is regulated by post-translational modifications (PTMs) of CapZβ1. In rapidly hypertrophying neonatal rat ventricular myocytes (NRVMs) stimulated by phenylephrine (PE), two-dimensional gel electrophoresis (2DGE) of CapZβ1 revealed a shift toward more negative charge. Consistent with this, mass spectrometry identified CapZβ1 phosphorylation on serine-204 and acetylation on lysine-199, two residues which are near the actin binding surface of CapZβ1. Ectopic expression of dominant negative PKCɛ (dnPKCɛ) in NRVMs blunted the PE-induced increase in CapZ dynamics, as evidenced by the kinetic constant (Kfrap) of fluorescence recovery after photobleaching (FRAP), and concomitantly reduced phosphorylation and acetylation of CapZβ1. Furthermore, inhibition of class I histone deacetylases (HDACs) increased lysine-199 acetylation on CapZβ1, which increased Kfrap of CapZ and stimulated actin dynamics. Finally, we show that PE treatment of NRVMs results in decreased binding of HDAC3 to myofibrils, suggesting a signal-dependent mechanism for the regulation of sarcomere-associated CapZβ1 acetylation. Taken together, this dual regulation through phosphorylation and acetylation of CapZβ1 provides a novel model for the regulation of myofibril growth during cardiac hypertrophy.
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Affiliation(s)
- Ying-Hsi Lin
- Department of Physiology and Biophysics, University of Illinois at Chicago, College of Medicine, Chicago, IL 60612-7342, United States; Department of Physiology & Biophysics, Center for Cardiovascular Research, University of Illinois at Chicago, Chicago, IL 60612-7342, United States
| | - Chad M Warren
- Department of Physiology and Biophysics, University of Illinois at Chicago, College of Medicine, Chicago, IL 60612-7342, United States; Department of Physiology & Biophysics, Center for Cardiovascular Research, University of Illinois at Chicago, Chicago, IL 60612-7342, United States
| | - Jieli Li
- Department of Physiology and Biophysics, University of Illinois at Chicago, College of Medicine, Chicago, IL 60612-7342, United States; Department of Physiology & Biophysics, Center for Cardiovascular Research, University of Illinois at Chicago, Chicago, IL 60612-7342, United States
| | - Timothy A McKinsey
- Department of Medicine, Division of Cardiology and Center for Fibrosis Research and Translation, University of Colorado Anschutz Medical Campus, Aurora, CO 80045-0508, United States
| | - Brenda Russell
- Department of Physiology and Biophysics, University of Illinois at Chicago, College of Medicine, Chicago, IL 60612-7342, United States; Department of Physiology & Biophysics, Center for Cardiovascular Research, University of Illinois at Chicago, Chicago, IL 60612-7342, United States.
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Broughton KM, Li J, Sarmah E, Warren CM, Lin YH, Henze MP, Sanchez-Freire V, Solaro RJ, Russell B. A myosin activator improves actin assembly and sarcomere function of human-induced pluripotent stem cell-derived cardiomyocytes with a troponin T point mutation. Am J Physiol Heart Circ Physiol 2016; 311:H107-17. [PMID: 27199119 DOI: 10.1152/ajpheart.00162.2016] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/23/2016] [Accepted: 05/02/2016] [Indexed: 11/22/2022]
Abstract
We have investigated cardiac myocytes derived from human-induced pluripotent stem cells (iPSC-CMs) from two normal control and two family members expressing a mutant cardiac troponin T (cTnT-R173W) linked to dilated cardiomyopathy (DCM). cTnT is a regulatory protein of the sarcomeric thin filament. The loss of this basic charge, which is strategically located to control tension, has consequences leading to progressive DCM. iPSC-CMs serve as a valuable platform for understanding clinically relevant mutations in sarcomeric proteins; however, there are important questions to be addressed with regard to myocyte adaptation that we model here by plating iPSC-CMs on softer substrates (100 kPa) to create a more physiologic environment during recovery and maturation of iPSC-CMs after thawing from cryopreservation. During the first week of culture of the iPSC-CMs, we have determined structural and functional characteristics as well as actin assembly dynamics. Shortening, actin content, and actin assembly dynamics were depressed in CMs from the severely affected mutant at 1 wk of culture, but by 2 wk differences were less apparent. Sarcomeric troponin and myosin isoform composition were fetal/neonatal. Furthermore, the troponin complex, reconstituted with wild-type cTnT or recombinant cTnT-R173W, depressed the entry of cross-bridges into the force-generating state, which can be reversed by the myosin activator omecamtiv mecarbil. Therapeutic doses of this drug increased both contractility and the content of F-actin in the mutant iPSC-CMs. Collectively, our data suggest the use of a myosin activation reagent to restore function within patient-specific iPSC-CMs may aid in understanding and treating this familial DCM.
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Affiliation(s)
- K M Broughton
- Department of Bioengineering, University of Illinois at Chicago, Chicago, Illinois
| | - J Li
- Department of Physiology and Biophysics, University of Illinois at Chicago, Chicago, Illinois; and
| | - E Sarmah
- Department of Bioengineering, University of Illinois at Chicago, Chicago, Illinois
| | - C M Warren
- Department of Physiology and Biophysics, University of Illinois at Chicago, Chicago, Illinois; and
| | - Y-H Lin
- Department of Physiology and Biophysics, University of Illinois at Chicago, Chicago, Illinois; and
| | - M P Henze
- Department of Physiology and Biophysics, University of Illinois at Chicago, Chicago, Illinois; and
| | - V Sanchez-Freire
- Department of Medicine, Division of Cardiology, Stanford University School of Medicine, Stanford, California
| | - R J Solaro
- Department of Physiology and Biophysics, University of Illinois at Chicago, Chicago, Illinois; and
| | - B Russell
- Department of Physiology and Biophysics, University of Illinois at Chicago, Chicago, Illinois; and
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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Abstract
Although high fidelity measurements of posttranslational modifications (PTMs) of cardiac myofilament proteins exist, important issues remain regarding basic techniques of sample acquisition and storage. We investigated the effects of anesthetic regimen and sample storage conditions on PTMs of major ventricular sarcomeric proteins. Mice were anesthetized with pentobarbital (Nembutal), ketamine/xylazine mixture (Ket/Xyl), or tribromoethanol (Avertin), and the ventricular tissue was prepared and stored for 1, 7, 30, 60, or 90 days at −80°C. Myofilament protein phosphorylation and glutathionylation were analyzed by Pro-Q Diamond stain and Western blotting, respectively. With up to 7 days of storage, phosphorylation of troponin T was stable for samples from mice anesthetized with either Nembutal or Ket/Xyl but not Avertin; while myosin-binding protein C (MyBP-C) phosphorylation was reduced at 7 days with Nembutal and Ket/Xyl, though generally not significant until 90 days. Tropomyosin and regulatory myosin light chain phosphorylation were stable for up to 7 days regardless of the anesthetic regimen employed. In the case of Troponin I, by 7 days of storage there was a significant fall in phosphorylation across all anesthetics. Storage of samples from 30 to 90 days resulted in a general decrease in myofilament phosphorylation independent of the anesthetic. S-glutathionylation of MyBP-C presented a trend in reduced glutathionylation from days 30–90 in all anesthetics, with only day 90 being statistically significant. Our findings suggest that there are alterations in PTMs of major myofilament proteins from both storage and anesthetic selection, and that storage beyond 30 days will likely result in distortion of data.
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Affiliation(s)
- Megan S Utter
- Department of Physiology and Biophysics, Center for Cardiovascular Research, College of Medicine, University of Illinois at Chicago, Chicago, Illinois
| | - Chad M Warren
- Department of Physiology and Biophysics, Center for Cardiovascular Research, College of Medicine, University of Illinois at Chicago, Chicago, Illinois
| | - R John Solaro
- Department of Physiology and Biophysics, Center for Cardiovascular Research, College of Medicine, University of Illinois at Chicago, Chicago, Illinois
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34
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Rosas PC, Liu Y, Abdalla MI, Thomas CM, Kidwell DT, Dusio GF, Mukhopadhyay D, Kumar R, Baker KM, Mitchell BM, Powers PA, Fitzsimons DP, Patel BG, Warren CM, Solaro RJ, Moss RL, Tong CW. Phosphorylation of cardiac Myosin-binding protein-C is a critical mediator of diastolic function. Circ Heart Fail 2015; 8:582-94. [PMID: 25740839 DOI: 10.1161/circheartfailure.114.001550] [Citation(s) in RCA: 82] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/15/2014] [Accepted: 02/24/2015] [Indexed: 01/06/2023]
Abstract
BACKGROUND Heart failure (HF) with preserved ejection fraction (HFpEF) accounts for ≈50% of all cases of HF and currently has no effective treatment. Diastolic dysfunction underlies HFpEF; therefore, elucidation of the mechanisms that mediate relaxation can provide new potential targets for treatment. Cardiac myosin-binding protein-C (cMyBP-C) is a thick filament protein that modulates cross-bridge cycling rates via alterations in its phosphorylation status. Thus, we hypothesize that phosphorylated cMyBP-C accelerates the rate of cross-bridge detachment, thereby enhancing relaxation to mediate diastolic function. METHODS AND RESULTS We compared mouse models expressing phosphorylation-deficient cMyBP-C(S273A/S282A/S302A)-cMyBP-C(t3SA), phosphomimetic cMyBP-C(S273D/S282D/S302D)-cMyBP-C(t3SD), and wild-type-control cMyBP-C(tWT) to elucidate the functional effects of cMyBP-C phosphorylation. Decreased voluntary running distances, increased lung/body weight ratios, and increased brain natriuretic peptide levels in cMyBP-C(t3SA) mice demonstrate that phosphorylation deficiency is associated with signs of HF. Echocardiography (ejection fraction and myocardial relaxation velocity) and pressure/volume measurements (-dP/dtmin, pressure decay time constant τ-Glantz, and passive filling stiffness) show that cMyBP-C phosphorylation enhances myocardial relaxation in cMyBP-C(t3SD) mice, whereas deficient cMyBP-C phosphorylation causes diastolic dysfunction with HFpEF in cMyBP-C(t3SA) mice. Simultaneous force and [Ca(2+)]i measurements on intact papillary muscles show that enhancement of relaxation in cMyBP-C(t3SD) mice and impairment of relaxation in cMyBP-C(t3SA) mice are not because of altered [Ca(2+)]i handling, implicating that altered cross-bridge detachment rates mediate these changes in relaxation rates. CONCLUSIONS cMyBP-C phosphorylation enhances relaxation, whereas deficient phosphorylation causes diastolic dysfunction and phenotypes resembling HFpEF. Thus, cMyBP-C is a potential target for treatment of HFpEF.
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Affiliation(s)
- Paola C Rosas
- From the Department of Medical Physiology (P.C.R., Y.L., M.I.A., B.M.M., C.W.T.) and Division of Molecular Cardiology, Department of Medicine (C.M.T., R.K., K.M.B.), Texas A&M University Health Science Center, College of Medicine, Temple City; Internal Medicine/Division of Cardiology (D.T.K., C.W.T.) and Department of Surgery (G.F.D., D.M.), Baylor Scott & White Health-Central Texas, Temple City; Department of Cell and Regenerative Biology and Biotechnology Center, University of Wisconsin School of Medicine and Public Health, Madison (P.A.P., D.P.F., R.L.M.); and Department of Physiology and Biophysics and Center for Cardiovascular Research, College of Medicine, University of Illinois, Chicago (B.G.P., C.M.W., R.J.S.)
| | - Yang Liu
- From the Department of Medical Physiology (P.C.R., Y.L., M.I.A., B.M.M., C.W.T.) and Division of Molecular Cardiology, Department of Medicine (C.M.T., R.K., K.M.B.), Texas A&M University Health Science Center, College of Medicine, Temple City; Internal Medicine/Division of Cardiology (D.T.K., C.W.T.) and Department of Surgery (G.F.D., D.M.), Baylor Scott & White Health-Central Texas, Temple City; Department of Cell and Regenerative Biology and Biotechnology Center, University of Wisconsin School of Medicine and Public Health, Madison (P.A.P., D.P.F., R.L.M.); and Department of Physiology and Biophysics and Center for Cardiovascular Research, College of Medicine, University of Illinois, Chicago (B.G.P., C.M.W., R.J.S.)
| | - Mohamed I Abdalla
- From the Department of Medical Physiology (P.C.R., Y.L., M.I.A., B.M.M., C.W.T.) and Division of Molecular Cardiology, Department of Medicine (C.M.T., R.K., K.M.B.), Texas A&M University Health Science Center, College of Medicine, Temple City; Internal Medicine/Division of Cardiology (D.T.K., C.W.T.) and Department of Surgery (G.F.D., D.M.), Baylor Scott & White Health-Central Texas, Temple City; Department of Cell and Regenerative Biology and Biotechnology Center, University of Wisconsin School of Medicine and Public Health, Madison (P.A.P., D.P.F., R.L.M.); and Department of Physiology and Biophysics and Center for Cardiovascular Research, College of Medicine, University of Illinois, Chicago (B.G.P., C.M.W., R.J.S.)
| | - Candice M Thomas
- From the Department of Medical Physiology (P.C.R., Y.L., M.I.A., B.M.M., C.W.T.) and Division of Molecular Cardiology, Department of Medicine (C.M.T., R.K., K.M.B.), Texas A&M University Health Science Center, College of Medicine, Temple City; Internal Medicine/Division of Cardiology (D.T.K., C.W.T.) and Department of Surgery (G.F.D., D.M.), Baylor Scott & White Health-Central Texas, Temple City; Department of Cell and Regenerative Biology and Biotechnology Center, University of Wisconsin School of Medicine and Public Health, Madison (P.A.P., D.P.F., R.L.M.); and Department of Physiology and Biophysics and Center for Cardiovascular Research, College of Medicine, University of Illinois, Chicago (B.G.P., C.M.W., R.J.S.)
| | - David T Kidwell
- From the Department of Medical Physiology (P.C.R., Y.L., M.I.A., B.M.M., C.W.T.) and Division of Molecular Cardiology, Department of Medicine (C.M.T., R.K., K.M.B.), Texas A&M University Health Science Center, College of Medicine, Temple City; Internal Medicine/Division of Cardiology (D.T.K., C.W.T.) and Department of Surgery (G.F.D., D.M.), Baylor Scott & White Health-Central Texas, Temple City; Department of Cell and Regenerative Biology and Biotechnology Center, University of Wisconsin School of Medicine and Public Health, Madison (P.A.P., D.P.F., R.L.M.); and Department of Physiology and Biophysics and Center for Cardiovascular Research, College of Medicine, University of Illinois, Chicago (B.G.P., C.M.W., R.J.S.)
| | - Giuseppina F Dusio
- From the Department of Medical Physiology (P.C.R., Y.L., M.I.A., B.M.M., C.W.T.) and Division of Molecular Cardiology, Department of Medicine (C.M.T., R.K., K.M.B.), Texas A&M University Health Science Center, College of Medicine, Temple City; Internal Medicine/Division of Cardiology (D.T.K., C.W.T.) and Department of Surgery (G.F.D., D.M.), Baylor Scott & White Health-Central Texas, Temple City; Department of Cell and Regenerative Biology and Biotechnology Center, University of Wisconsin School of Medicine and Public Health, Madison (P.A.P., D.P.F., R.L.M.); and Department of Physiology and Biophysics and Center for Cardiovascular Research, College of Medicine, University of Illinois, Chicago (B.G.P., C.M.W., R.J.S.)
| | - Dhriti Mukhopadhyay
- From the Department of Medical Physiology (P.C.R., Y.L., M.I.A., B.M.M., C.W.T.) and Division of Molecular Cardiology, Department of Medicine (C.M.T., R.K., K.M.B.), Texas A&M University Health Science Center, College of Medicine, Temple City; Internal Medicine/Division of Cardiology (D.T.K., C.W.T.) and Department of Surgery (G.F.D., D.M.), Baylor Scott & White Health-Central Texas, Temple City; Department of Cell and Regenerative Biology and Biotechnology Center, University of Wisconsin School of Medicine and Public Health, Madison (P.A.P., D.P.F., R.L.M.); and Department of Physiology and Biophysics and Center for Cardiovascular Research, College of Medicine, University of Illinois, Chicago (B.G.P., C.M.W., R.J.S.)
| | - Rajesh Kumar
- From the Department of Medical Physiology (P.C.R., Y.L., M.I.A., B.M.M., C.W.T.) and Division of Molecular Cardiology, Department of Medicine (C.M.T., R.K., K.M.B.), Texas A&M University Health Science Center, College of Medicine, Temple City; Internal Medicine/Division of Cardiology (D.T.K., C.W.T.) and Department of Surgery (G.F.D., D.M.), Baylor Scott & White Health-Central Texas, Temple City; Department of Cell and Regenerative Biology and Biotechnology Center, University of Wisconsin School of Medicine and Public Health, Madison (P.A.P., D.P.F., R.L.M.); and Department of Physiology and Biophysics and Center for Cardiovascular Research, College of Medicine, University of Illinois, Chicago (B.G.P., C.M.W., R.J.S.)
| | - Kenneth M Baker
- From the Department of Medical Physiology (P.C.R., Y.L., M.I.A., B.M.M., C.W.T.) and Division of Molecular Cardiology, Department of Medicine (C.M.T., R.K., K.M.B.), Texas A&M University Health Science Center, College of Medicine, Temple City; Internal Medicine/Division of Cardiology (D.T.K., C.W.T.) and Department of Surgery (G.F.D., D.M.), Baylor Scott & White Health-Central Texas, Temple City; Department of Cell and Regenerative Biology and Biotechnology Center, University of Wisconsin School of Medicine and Public Health, Madison (P.A.P., D.P.F., R.L.M.); and Department of Physiology and Biophysics and Center for Cardiovascular Research, College of Medicine, University of Illinois, Chicago (B.G.P., C.M.W., R.J.S.)
| | - Brett M Mitchell
- From the Department of Medical Physiology (P.C.R., Y.L., M.I.A., B.M.M., C.W.T.) and Division of Molecular Cardiology, Department of Medicine (C.M.T., R.K., K.M.B.), Texas A&M University Health Science Center, College of Medicine, Temple City; Internal Medicine/Division of Cardiology (D.T.K., C.W.T.) and Department of Surgery (G.F.D., D.M.), Baylor Scott & White Health-Central Texas, Temple City; Department of Cell and Regenerative Biology and Biotechnology Center, University of Wisconsin School of Medicine and Public Health, Madison (P.A.P., D.P.F., R.L.M.); and Department of Physiology and Biophysics and Center for Cardiovascular Research, College of Medicine, University of Illinois, Chicago (B.G.P., C.M.W., R.J.S.)
| | - Patricia A Powers
- From the Department of Medical Physiology (P.C.R., Y.L., M.I.A., B.M.M., C.W.T.) and Division of Molecular Cardiology, Department of Medicine (C.M.T., R.K., K.M.B.), Texas A&M University Health Science Center, College of Medicine, Temple City; Internal Medicine/Division of Cardiology (D.T.K., C.W.T.) and Department of Surgery (G.F.D., D.M.), Baylor Scott & White Health-Central Texas, Temple City; Department of Cell and Regenerative Biology and Biotechnology Center, University of Wisconsin School of Medicine and Public Health, Madison (P.A.P., D.P.F., R.L.M.); and Department of Physiology and Biophysics and Center for Cardiovascular Research, College of Medicine, University of Illinois, Chicago (B.G.P., C.M.W., R.J.S.)
| | - Daniel P Fitzsimons
- From the Department of Medical Physiology (P.C.R., Y.L., M.I.A., B.M.M., C.W.T.) and Division of Molecular Cardiology, Department of Medicine (C.M.T., R.K., K.M.B.), Texas A&M University Health Science Center, College of Medicine, Temple City; Internal Medicine/Division of Cardiology (D.T.K., C.W.T.) and Department of Surgery (G.F.D., D.M.), Baylor Scott & White Health-Central Texas, Temple City; Department of Cell and Regenerative Biology and Biotechnology Center, University of Wisconsin School of Medicine and Public Health, Madison (P.A.P., D.P.F., R.L.M.); and Department of Physiology and Biophysics and Center for Cardiovascular Research, College of Medicine, University of Illinois, Chicago (B.G.P., C.M.W., R.J.S.)
| | - Bindiya G Patel
- From the Department of Medical Physiology (P.C.R., Y.L., M.I.A., B.M.M., C.W.T.) and Division of Molecular Cardiology, Department of Medicine (C.M.T., R.K., K.M.B.), Texas A&M University Health Science Center, College of Medicine, Temple City; Internal Medicine/Division of Cardiology (D.T.K., C.W.T.) and Department of Surgery (G.F.D., D.M.), Baylor Scott & White Health-Central Texas, Temple City; Department of Cell and Regenerative Biology and Biotechnology Center, University of Wisconsin School of Medicine and Public Health, Madison (P.A.P., D.P.F., R.L.M.); and Department of Physiology and Biophysics and Center for Cardiovascular Research, College of Medicine, University of Illinois, Chicago (B.G.P., C.M.W., R.J.S.)
| | - Chad M Warren
- From the Department of Medical Physiology (P.C.R., Y.L., M.I.A., B.M.M., C.W.T.) and Division of Molecular Cardiology, Department of Medicine (C.M.T., R.K., K.M.B.), Texas A&M University Health Science Center, College of Medicine, Temple City; Internal Medicine/Division of Cardiology (D.T.K., C.W.T.) and Department of Surgery (G.F.D., D.M.), Baylor Scott & White Health-Central Texas, Temple City; Department of Cell and Regenerative Biology and Biotechnology Center, University of Wisconsin School of Medicine and Public Health, Madison (P.A.P., D.P.F., R.L.M.); and Department of Physiology and Biophysics and Center for Cardiovascular Research, College of Medicine, University of Illinois, Chicago (B.G.P., C.M.W., R.J.S.)
| | - R John Solaro
- From the Department of Medical Physiology (P.C.R., Y.L., M.I.A., B.M.M., C.W.T.) and Division of Molecular Cardiology, Department of Medicine (C.M.T., R.K., K.M.B.), Texas A&M University Health Science Center, College of Medicine, Temple City; Internal Medicine/Division of Cardiology (D.T.K., C.W.T.) and Department of Surgery (G.F.D., D.M.), Baylor Scott & White Health-Central Texas, Temple City; Department of Cell and Regenerative Biology and Biotechnology Center, University of Wisconsin School of Medicine and Public Health, Madison (P.A.P., D.P.F., R.L.M.); and Department of Physiology and Biophysics and Center for Cardiovascular Research, College of Medicine, University of Illinois, Chicago (B.G.P., C.M.W., R.J.S.)
| | - Richard L Moss
- From the Department of Medical Physiology (P.C.R., Y.L., M.I.A., B.M.M., C.W.T.) and Division of Molecular Cardiology, Department of Medicine (C.M.T., R.K., K.M.B.), Texas A&M University Health Science Center, College of Medicine, Temple City; Internal Medicine/Division of Cardiology (D.T.K., C.W.T.) and Department of Surgery (G.F.D., D.M.), Baylor Scott & White Health-Central Texas, Temple City; Department of Cell and Regenerative Biology and Biotechnology Center, University of Wisconsin School of Medicine and Public Health, Madison (P.A.P., D.P.F., R.L.M.); and Department of Physiology and Biophysics and Center for Cardiovascular Research, College of Medicine, University of Illinois, Chicago (B.G.P., C.M.W., R.J.S.)
| | - Carl W Tong
- From the Department of Medical Physiology (P.C.R., Y.L., M.I.A., B.M.M., C.W.T.) and Division of Molecular Cardiology, Department of Medicine (C.M.T., R.K., K.M.B.), Texas A&M University Health Science Center, College of Medicine, Temple City; Internal Medicine/Division of Cardiology (D.T.K., C.W.T.) and Department of Surgery (G.F.D., D.M.), Baylor Scott & White Health-Central Texas, Temple City; Department of Cell and Regenerative Biology and Biotechnology Center, University of Wisconsin School of Medicine and Public Health, Madison (P.A.P., D.P.F., R.L.M.); and Department of Physiology and Biophysics and Center for Cardiovascular Research, College of Medicine, University of Illinois, Chicago (B.G.P., C.M.W., R.J.S.).
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Abstract
Proteins larger than 200 kDa are difficult to separate electrophoretically using polyacrylamide gels, and their transfer during western blotting is typically incomplete. A vertical SDS agarose gel system was developed that has vastly improved resolving power for very large proteins. Complete transfer of proteins as large as titin (Mr 3,000-3,700 kDa) onto blots can be achieved. The addition of a sulfhydryl reducing agent in the upper reservoir buffer and transfer buffer markedly improves the blotting of large proteins.
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Affiliation(s)
- Marion L Greaser
- Muscle Biology Laboratory, University of Wisconsin-Madison, 1805 Linden Drive, Madison, WI, 53706, USA,
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36
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Simon JN, Chowdhury SAK, Warren CM, Sadayappan S, Wieczorek DF, Solaro RJ, Wolska BM. Ceramide-mediated depression in cardiomyocyte contractility through PKC activation and modulation of myofilament protein phosphorylation. Basic Res Cardiol 2014; 109:445. [PMID: 25280528 DOI: 10.1007/s00395-014-0445-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/29/2013] [Revised: 09/25/2014] [Accepted: 09/26/2014] [Indexed: 12/16/2022]
Abstract
Although ceramide accumulation in the heart is considered a major factor in promoting apoptosis and cardiac disorders, including heart failure, lipotoxicity and ischemia-reperfusion injury, little is known about ceramide's role in mediating changes in contractility. In the present study, we measured the functional consequences of acute exposure of isolated field-stimulated adult rat cardiomyocytes to C6-ceramide. Exogenous ceramide treatment depressed the peak amplitude and the maximal velocity of shortening without altering intracellular calcium levels or kinetics. The inactive ceramide analog C6-dihydroceramide had no effect on myocyte shortening or [Ca(2+)]i transients. Experiments testing a potential role for C6-ceramide-mediated effects on activation of protein kinase C (PKC) demonstrated evidence for signaling through the calcium-independent isoform, PKCε. We employed 2-dimensional electrophoresis and anti-phospho-peptide antibodies to test whether treatment of the cardiomyocytes with C6-ceramide altered myocyte shortening via PKC-dependent phosphorylation of myofilament proteins. Compared to controls, myocytes treated with ceramide exhibited increased phosphorylation of myosin binding protein-C (cMyBP-C), specifically at Ser273 and Ser302, and troponin I (cTnI) at sites apart from Ser23/24, which could be attenuated with PKC inhibition. We conclude that the altered myofilament response to calcium resulting from multiple sites of PKC-dependent phosphorylation contributes to contractile dysfunction that is associated with cardiac diseases in which elevations in ceramides are present.
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Affiliation(s)
- Jillian N Simon
- Department of Physiology and Biophysics and Center for Cardiovascular Research, College of Medicine, University of Illinois, Chicago, IL, 60612, USA
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37
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Alegre-Cebollada J, Kosuri P, Giganti D, Eckels E, Rivas-Pardo JA, Hamdani N, Warren CM, Solaro RJ, Linke WA, Fernández JM. S-glutathionylation of cryptic cysteines enhances titin elasticity by blocking protein folding. Cell 2014; 156:1235-1246. [PMID: 24630725 DOI: 10.1016/j.cell.2014.01.056] [Citation(s) in RCA: 122] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2013] [Revised: 10/17/2013] [Accepted: 01/24/2014] [Indexed: 12/16/2022]
Abstract
The giant elastic protein titin is a determinant factor in how much blood fills the left ventricle during diastole and thus in the etiology of heart disease. Titin has been identified as a target of S-glutathionylation, an end product of the nitric-oxide-signaling cascade that increases cardiac muscle elasticity. However, it is unknown how S-glutathionylation may regulate the elasticity of titin and cardiac tissue. Here, we show that mechanical unfolding of titin immunoglobulin (Ig) domains exposes buried cysteine residues, which then can be S-glutathionylated. S-glutathionylation of cryptic cysteines greatly decreases the mechanical stability of the parent Ig domain as well as its ability to fold. Both effects favor a more extensible state of titin. Furthermore, we demonstrate that S-glutathionylation of cryptic cysteines in titin mediates mechanochemical modulation of the elasticity of human cardiomyocytes. We propose that posttranslational modification of cryptic residues is a general mechanism to regulate tissue elasticity.
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Affiliation(s)
| | - Pallav Kosuri
- Department of Biological Sciences, Columbia University, New York, NY 10027, USA; Graduate Program in Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA
| | - David Giganti
- Department of Biological Sciences, Columbia University, New York, NY 10027, USA
| | - Edward Eckels
- Department of Biological Sciences, Columbia University, New York, NY 10027, USA; Columbia College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA
| | | | - Nazha Hamdani
- Department of Cardiovascular Physiology, Ruhr University Bochum, 44780 Bochum, Germany
| | - Chad M Warren
- Department of Physiology and Biophysics, College of Medicine, University of Illinois at Chicago, Chicago, IL 60612, USA
| | - R John Solaro
- Department of Physiology and Biophysics, College of Medicine, University of Illinois at Chicago, Chicago, IL 60612, USA
| | - Wolfgang A Linke
- Department of Cardiovascular Physiology, Ruhr University Bochum, 44780 Bochum, Germany
| | - Julio M Fernández
- Department of Biological Sciences, Columbia University, New York, NY 10027, USA.
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38
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Alegre-Cebollada J, Kosuri P, Giganti D, Eckels E, Rivas-Pardo JA, Hamdani N, Warren CM, Solaro RJ, Linke WA, Fernández JM. S-glutathionylation of cryptic cysteines enhances titin elasticity by blocking protein folding. Cell 2014. [PMID: 24630725 DOI: 10.1016/j.cell.2014.01.056.s-glutathionylation] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
The giant elastic protein titin is a determinant factor in how much blood fills the left ventricle during diastole and thus in the etiology of heart disease. Titin has been identified as a target of S-glutathionylation, an end product of the nitric-oxide-signaling cascade that increases cardiac muscle elasticity. However, it is unknown how S-glutathionylation may regulate the elasticity of titin and cardiac tissue. Here, we show that mechanical unfolding of titin immunoglobulin (Ig) domains exposes buried cysteine residues, which then can be S-glutathionylated. S-glutathionylation of cryptic cysteines greatly decreases the mechanical stability of the parent Ig domain as well as its ability to fold. Both effects favor a more extensible state of titin. Furthermore, we demonstrate that S-glutathionylation of cryptic cysteines in titin mediates mechanochemical modulation of the elasticity of human cardiomyocytes. We propose that posttranslational modification of cryptic residues is a general mechanism to regulate tissue elasticity.
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Affiliation(s)
| | - Pallav Kosuri
- Department of Biological Sciences, Columbia University, New York, NY 10027, USA; Graduate Program in Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA
| | - David Giganti
- Department of Biological Sciences, Columbia University, New York, NY 10027, USA
| | - Edward Eckels
- Department of Biological Sciences, Columbia University, New York, NY 10027, USA; Columbia College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA
| | | | - Nazha Hamdani
- Department of Cardiovascular Physiology, Ruhr University Bochum, 44780 Bochum, Germany
| | - Chad M Warren
- Department of Physiology and Biophysics, College of Medicine, University of Illinois at Chicago, Chicago, IL 60612, USA
| | - R John Solaro
- Department of Physiology and Biophysics, College of Medicine, University of Illinois at Chicago, Chicago, IL 60612, USA
| | - Wolfgang A Linke
- Department of Cardiovascular Physiology, Ruhr University Bochum, 44780 Bochum, Germany
| | - Julio M Fernández
- Department of Biological Sciences, Columbia University, New York, NY 10027, USA.
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Alves ML, Dias FAL, Gaffin RD, Simon JN, Montminy EM, Biesiadecki BJ, Hinken AC, Warren CM, Utter MS, Davis RT, Sakthivel S, Robbins J, Wieczorek DF, Solaro RJ, Wolska BM. Desensitization of myofilaments to Ca2+ as a therapeutic target for hypertrophic cardiomyopathy with mutations in thin filament proteins. ACTA ACUST UNITED AC 2014; 7:132-143. [PMID: 24585742 DOI: 10.1161/circgenetics.113.000324] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
BACKGROUND Hypertrophic cardiomyopathy (HCM) is a common genetic disorder caused mainly by mutations in sarcomeric proteins and is characterized by maladaptive myocardial hypertrophy, diastolic heart failure, increased myofilament Ca(2+) sensitivity, and high susceptibility to sudden death. We tested the following hypothesis: correction of the increased myofilament sensitivity can delay or prevent the development of the HCM phenotype. METHODS AND RESULTS We used an HCM mouse model with an E180G mutation in α-tropomyosin (Tm180) that demonstrates increased myofilament Ca(2+) sensitivity, severe hypertrophy, and diastolic dysfunction. To test our hypothesis, we reduced myofilament Ca(2+) sensitivity in Tm180 mice by generating a double transgenic mouse line. We crossed Tm180 mice with mice expressing a pseudophosphorylated cardiac troponin I (S23D and S24D; TnI-PP). TnI-PP mice demonstrated a reduced myofilament Ca(2+) sensitivity compared with wild-type mice. The development of pathological hypertrophy did not occur in mice expressing both Tm180 and TnI-PP. Left ventricle performance was improved in double transgenic compared with their Tm180 littermates, which express wild-type cardiac troponin I. Hearts of double transgenic mice demonstrated no changes in expression of phospholamban and sarcoplasmic reticulum Ca(2+) ATPase, increased levels of phospholamban and troponin T phosphorylation, and reduced phosphorylation of TnI compared with Tm180 mice. Moreover, expression of TnI-PP in Tm180 hearts inhibited modifications in the activity of extracellular signal-regulated kinase and zinc finger-containing transcription factor GATA in Tm180 hearts. CONCLUSIONS Our data strongly indicate that reduction of myofilament sensitivity to Ca(2+) and associated correction of abnormal relaxation can delay or prevent development of HCM and should be considered as a therapeutic target for HCM.
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Affiliation(s)
- Marco L Alves
- Department of Physiology and Biophysics, Center for Cardiovascular Research, University of Illinois, Chicago, IL.,Department of Physiology and Department of Cell Biology, Federal University of Parana, Curitiba, Brazil
| | - Fernando A L Dias
- Department of Physiology and Biophysics, Center for Cardiovascular Research, University of Illinois, Chicago, IL.,Department of Physiology and Department of Cell Biology, Federal University of Parana, Curitiba, Brazil
| | - Robert D Gaffin
- Department of Physiology and Biophysics, Center for Cardiovascular Research, University of Illinois, Chicago, IL
| | - Jillian N Simon
- Department of Physiology and Biophysics, Center for Cardiovascular Research, University of Illinois, Chicago, IL
| | - Eric M Montminy
- Department of Physiology and Biophysics, Center for Cardiovascular Research, University of Illinois, Chicago, IL
| | - Brandon J Biesiadecki
- Department of Physiology and Biophysics, Center for Cardiovascular Research, University of Illinois, Chicago, IL.,Department of Physiology and Cell Biology, The Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH
| | - Aaron C Hinken
- Department of Physiology and Biophysics, Center for Cardiovascular Research, University of Illinois, Chicago, IL
| | - Chad M Warren
- Department of Physiology and Biophysics, Center for Cardiovascular Research, University of Illinois, Chicago, IL
| | - Megan S Utter
- Department of Physiology and Biophysics, Center for Cardiovascular Research, University of Illinois, Chicago, IL
| | - Robert T Davis
- Department of Physiology and Biophysics, Center for Cardiovascular Research, University of Illinois, Chicago, IL
| | - Sadayappan Sakthivel
- Division of Molecular Cardiovascular Biology, Department of Pediatrics, Cincinnati Children's Hospital Medical Center, Cincinnati
| | - Jeffrey Robbins
- Division of Molecular Cardiovascular Biology, Department of Pediatrics, Cincinnati Children's Hospital Medical Center, Cincinnati
| | - David F Wieczorek
- Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati, College of Medicine
| | - R John Solaro
- Department of Physiology and Biophysics, Center for Cardiovascular Research, University of Illinois, Chicago, IL
| | - Beata M Wolska
- Department of Medicine, Section of Cardiology, University of Illinois, Chicago, IL.,Department of Physiology and Biophysics, Center for Cardiovascular Research, University of Illinois, Chicago, IL
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40
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Lin YH, Warren CM, Russell B. Acetylation and Phosphorylation Post-Translational Modifications of the CapZ β1 Subunit Regulate FRAP Dynamics Leading to Myocyte Hypertrophy. Biophys J 2014. [DOI: 10.1016/j.bpj.2013.11.4266] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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41
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Monasky MM, Taglieri DM, Henze M, Warren CM, Utter MS, Soergel DG, Violin JD, Solaro RJ. The β-arrestin-biased ligand TRV120023 inhibits angiotensin II-induced cardiac hypertrophy while preserving enhanced myofilament response to calcium. Am J Physiol Heart Circ Physiol 2013; 305:H856-66. [PMID: 23873795 DOI: 10.1152/ajpheart.00327.2013] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
In the present study, we compared the cardioprotective effects of TRV120023, a novel angiotensin II (ANG II) type 1 receptor (AT1R) ligand, which blocks G protein coupling but stimulates β-arrestin signaling, against treatment with losartan, a conventional AT1R blocker in the treatment of cardiac hypertrophy and regulation of myofilament activity and phosphorylation. Rats were subjected to 3 wk of treatment with saline, ANG II, ANG II + losartan, ANG II + TRV120023, or TRV120023 alone. ANG II induced increased left ventricular mass compared with rats that received ANG II + losartan or ANG II + TRV120023. Compared with saline controls, ANG II induced a significant increase in pCa50 and maximum Ca(2+)-activated myofilament tension but reduced the Hill coefficient (nH). TRV120023 increased maximum tension and pCa50, although to lesser extent than ANG II. In contrast to ANG II, TRV120023 increased nH. Losartan blocked the effects of ANG II on pCa50 and nH and reduced maximum tension below that of saline controls. ANG II + TRV120023 showed responses similar to those of TRV120023 alone; compared with ANG II + losartan, ANG II + TRV120023 preserved maximum tension and increased both pCa50 and cooperativity. Tropomyosin phosphorylation was lower in myofilaments from saline-treated hearts compared with the other groups. Phosphorylation of cardiac troponin I was significantly reduced in ANG II + TRV120023 and TRV120023 groups versus saline controls, and myosin-binding protein C phosphorylation at Ser(282) was unaffected by ANG II or losartan but significantly reduced with TRV120023 treatment compared with all other groups. Our data indicate that TRV120023-related promotion of β-arrestin signaling and enhanced contractility involves a mechanism promoting the myofilament response to Ca(2+) via altered protein phosphorylation. Selective activation of β-arrestin-dependent pathways may provide advantages over conventional AT1R blockers.
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Affiliation(s)
- Michelle M Monasky
- Department of Physiology and Biophysics and Center for Cardiovascular Research, College of Medicine, University of Illinois, Chicago, Illinois; and
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42
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Lai HL, Grachoff M, McGinley AL, Khan FF, Warren CM, Chowdhury SAK, Wolska BM, Solaro RJ, Geenen DL, Wang QT. Maintenance of adult cardiac function requires the chromatin factor Asxl2. J Mol Cell Cardiol 2012; 53:734-41. [PMID: 23046516 DOI: 10.1016/j.yjmcc.2012.08.014] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/07/2011] [Revised: 08/16/2012] [Accepted: 08/18/2012] [Indexed: 11/17/2022]
Abstract
During development and differentiation, cell type-specific chromatin configurations are set up to facilitate cell type-specific gene expression. Defects in the establishment or the maintenance of the correct chromatin configuration have been associated with diseases ranging from leukemia to muscular dystrophy. The heart expresses many chromatin factors, and we are only beginning to understand their roles in heart development and function. We have previously shown that the chromatin regulator Asxl2 is highly expressed in the murine heart both during development and adulthood. In the absence of Asxl2, there is a significant reduction in trimethylation of histone H3 lysine 27 (H3K27), a histone mark associated with lineage-specific silencing of developmental genes. Here we present evidence that Asxl2 is required for the long-term maintenance of ventricular function and for the maintenance of normal cardiac gene expression. Asxl2(-/-) hearts displayed progressive deterioration of ventricular function. By 10 months of age, there was ~37% reduction in fractional shortening in Asxl2(-/-) hearts compared to wild-type. Analysis of the expression of myofibril proteins suggests that Asxl2 is required for the repression of β-MHC. Asxl2(-/-) hearts did not exhibit hypertrophy, suggesting that the de-repression of β-MHC was not the result of hypertrophic response. Instead, Asxl2 and the histone methyltansferase Ezh2 co-localize to β-MHC promoter, suggesting that Asxl2 directly represses β-MHC. Interrogation of the CardioGenomics database revealed that ASXL2 is down-regulated in the hearts of patients with ischemic or idiopathic dilated cardiomyopathy. We propose that chromatin factors like Asxl2 function in the adult heart to regulate cell type- and stage-specific patterns of gene expression, and the disruption of such regulation may be involved in the etiology and/or development of certain forms of human heart disease.
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MESH Headings
- Animals
- Blood Pressure
- Cardiomyopathy, Dilated/metabolism
- Cardiomyopathy, Dilated/pathology
- Cardiomyopathy, Dilated/physiopathology
- Case-Control Studies
- Cell Size
- Cyclic AMP-Dependent Protein Kinases/metabolism
- Enhancer of Zeste Homolog 2 Protein
- Female
- Gene Expression Regulation
- HEK293 Cells
- Humans
- Male
- Mice
- Mice, 129 Strain
- Mice, Inbred C57BL
- Mice, Knockout
- Myocardium/enzymology
- Myocardium/metabolism
- Myocardium/pathology
- Myocytes, Cardiac/enzymology
- Myocytes, Cardiac/metabolism
- Myocytes, Cardiac/physiology
- Myosin Heavy Chains/genetics
- Myosin Heavy Chains/metabolism
- Phosphorylation
- Polycomb Repressive Complex 2/metabolism
- Promoter Regions, Genetic
- Protein Processing, Post-Translational
- Repressor Proteins/genetics
- Repressor Proteins/metabolism
- Signal Transduction
- Stroke Volume
- Troponin I/metabolism
- Ventricular Function
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Affiliation(s)
- Hsiao-Lei Lai
- Department of Biological Sciences, University of Illinois at Chicago, Chicago, IL 60607, USA.
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Varghese ST, Holley-Cuthrell J, Warren CM, Kuenster A, Heydemann A. Abstract 186: AMP-Activated Protein Kinase Mediates Cardioprotection in the Regenerative MRL Mouse Strain. Circ Res 2012. [DOI: 10.1161/res.111.suppl_1.a186] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Introduction:
The
Murphy Roths Large (MRL/MpJ) mouse model is well-known for its healing and regenerative properties. The actual mechanisms promoting regeneration are still unknown. AMP activated protein kinase (AMPK) has been lauded for its role as a cardioprotective sensor of cellular metabolic stress, cell growth, and ATP depletion. Based on our preliminary data, we hypothesize that increased levels of AMPK in the MRL hearts is primarily responsible for its altered mitochondrial biogenesis and metabolism, reduced oxidative stress, and altered cardiac function in the MRL mice.
Methods:
Adult C57BL/6 (control) and MRL mice (n=5/group) were studied pre- and post-7 days of exercise, and post-exercise with 3 days injection of either
5-amino
-imidazole carboxamide riboside (AICAR, AMPK stimulator, 250ug/g, IP), or Compound C (AMPK inhibitor, 20ug/g, IP).
Results:
Compared to control at baseline, the MRL hearts had higher AMPK protein levels (9 fold increase, p<0.001), equivalent AMPK mRNA levels by qRT-PCR, and higher AMP to ATP ratios by HPLC (3 fold increase, p>0.05, n.s.). The MRL hearts also had increased mitochondria by electron microscopy (by 65 ± 4.5%, p<0.05), reduced HW to BW ratio (48% decrease, p<0.001), reduced cellular and mitochondrial reactive oxygen species (by DHE and Mitosox stains respectively), and increased glycolysis (Glut-4 sarcolemmal translocation). Hypertrophic response to exercise was greater in the MRL mice (HW/BW increased by 40% vs. 2% in control, p<0.001). Mimicking injury, Compound C reduced active phosphorylated AMPK protein levels in control (by 26%, p<0.05), while increased it in MRL mice (by 30%, p<0.05). AICAR injection significantly increased pAMPK protein in both strains (p=0.008). Baseline MRL mice echocardiographic analysis (vs. control) indicated higher systolic function, but increased diastolic E/A and E/E’ ratios (p<0.05). In the MRL hearts, Compound C treatment reduced %EF and %FS, while AICAR reduced post-exercise hypertrophy (p=0.02).
Conclusions:
This study highlights the cardioprotective role AMPK plays in the MRL mice, through its modulation of mitochondrial function and reduction of oxidative stress. This can in turn be used to develop new therapeutic treatment for heart failure.
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44
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Warren CM, Alves MS, Montminy EM, Simon JN, Gaffin RD, Rajan S, Wieczorek DF, Solaro RJ, Wolska BM. Rescue of a Dilated Cardiomyopathy Mouse Model Caused by a Mutation in Tropomyosin (E54K) by Expression of Slow Skeletal Troponin I. Biophys J 2012. [DOI: 10.1016/j.bpj.2011.11.3051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022] Open
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Pound KM, Arteaga GM, Fasano M, Wilder T, Fischer SK, Warren CM, Wende AR, Farjah M, Abel ED, Solaro RJ, Lewandowski ED. Expression of slow skeletal TnI in adult mouse hearts confers metabolic protection to ischemia. J Mol Cell Cardiol 2011; 51:236-43. [PMID: 21640727 DOI: 10.1016/j.yjmcc.2011.05.014] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/04/2011] [Revised: 04/26/2011] [Accepted: 05/14/2011] [Indexed: 12/30/2022]
Abstract
Changes in metabolic and myofilament phenotypes coincide in developing hearts. Posttranslational modification of sarcomere proteins influences contractility, affecting the energetic cost of contraction. However, metabolic adaptations to sarcomeric phenotypes are not well understood, particularly during pathophysiological stress. This study explored metabolic adaptations to expression of the fetal, slow skeletal muscle troponin I (ssTnI). Hearts expressing ssTnI exhibited no significant ATP loss during 5 min of global ischemia, while non-transgenic littermates (NTG) showed continual ATP loss. At 7 min ischemia TG-ssTnI hearts retained 80±12% of ATP versus 49±6% in NTG (P<0.05). Hearts expressing ssTnI also had increased AMPK phosphorylation. The mechanism of ATP preservation was augmented glycolysis. Glycolytic end products (lactate and alanine) were 38% higher in TG-ssTnI than NTG at 2 min and 27% higher at 5 min. This additional glycolysis was supported exclusively by exogenous glucose, and not glycogen. Thus, expression of a fetal myofilament protein in adult mouse hearts induced elevated anaerobic ATP production during ischemia via metabolic adaptations consistent with the resistance to hypoxia of fetal hearts. The general findings hold important relevance to both our current understanding of the association between metabolic and contractile phenotypes and the potential for invoking cardioprotective mechanisms against ischemic stress. This article is part of a Special Issue entitled "Possible Editorial".
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Affiliation(s)
- Kayla M Pound
- Program in Integrative Cardiac Metabolism, Center for Cardiovascular Research and Department of Physiology and Biophysics, University of Illinois at Chicago, College of Medicine, Chicago, IL 60612, USA
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Karam CN, Warren CM, Rajan S, de Tombe PP, Wieczorek DF, Solaro RJ. Expression of tropomyosin-κ induces dilated cardiomyopathy and depresses cardiac myofilament tension by mechanisms involving cross-bridge dependent activation and altered tropomyosin phosphorylation. J Muscle Res Cell Motil 2011; 31:315-22. [PMID: 21221740 DOI: 10.1007/s10974-010-9237-2] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2010] [Accepted: 12/23/2010] [Indexed: 12/23/2022]
Abstract
Tropomyosin-kappa (TPM1-κ) is a newly discovered tropomyosin (TM) isoform that is exclusively expressed in the human heart and generated by an alternative splicing of the α-TM gene. We reported that TPM1-κ expression was increased in the hearts of patients with chronic dilated cardiomyopathy (DCM). To increase our understanding of the significance of this shift in isoform population, we generated transgenic (TG) mice expressing TPM1-κ in the cardiac compartment where TPM1-κ replaces 90% of the native TM. We previously showed that there was a significant inhibition of the ability of strongly bound cross-bridges to induce activation of TG myofilaments (Rajan et al., Circulation 121:410-418, 2010). Here, we compared the force-Ca(2+) relations in detergent extracted (skinned) fiber bundles isolated from non-transgenic (NTG) and TG-TPM1-κ hearts at two sarcomere lengths (SLs). Our data demonstrated a significant decrease in the Ca(2+) sensitivity of the myofilaments from TG-TPM1-κ hearts with no change in the maximum developed tension, length-dependent activation, and the ratio of ATPase rate to tension. There was also no difference in the affinity and cooperativity of Ca(2+)-binding to troponin in thin filaments reconstituted with either TPM1-κ or α-TM. We also compared protein phosphorylation in NTG and TG-TPM1-κ myofilaments. There was a decrease in the total phosphorylation of TPM1-κ compared to α-TM, but no significant change in other major sarcomeric proteins. Our results identify a novel mode of myofilament desensitization to Ca(2+) associated with a DCM linked switch in TM isoform population.
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Affiliation(s)
- Chehade N Karam
- Department of Physiology and Biophysics, Center for Cardiovascular Research, College of Medicine, University of Illinois at Chicago, 835 S. Wolcott Ave. (M/C 901), Chicago, IL 60612-7342, USA
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Peña JR, Szkudlarek AC, Warren CM, Heinrich LS, Gaffin RD, Jagatheesan G, del Monte F, Hajjar RJ, Goldspink PH, Solaro RJ, Wieczorek DF, Wolska BM. Neonatal gene transfer of Serca2a delays onset of hypertrophic remodeling and improves function in familial hypertrophic cardiomyopathy. J Mol Cell Cardiol 2010; 49:993-1002. [PMID: 20854827 DOI: 10.1016/j.yjmcc.2010.09.010] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2009] [Revised: 08/25/2010] [Accepted: 09/10/2010] [Indexed: 10/19/2022]
Abstract
Familial hypertrophic cardiomyopathy (FHC) is an autosomal dominant genetic disorder linked to numerous mutations in the sarcomeric proteins. The clinical presentation of FHC is highly variable, but it is a major cause of sudden cardiac death in young adults with no specific treatments. We tested the hypothesis that early intervention in Ca(2+) regulation may prevent pathological hypertrophy and improve cardiac function in a FHC displaying increased myofilament sensitivity to Ca(2+) and diastolic dysfunction. A transgenic (TG) mouse model of FHC with a mutation in tropomyosin at position 180 was employed. Adenoviral-Serca2a (Ad.Ser) was injected into the left ventricle of 1-day-old non-transgenic (NTG) and TG mice. Ad.LacZ was injected as a control. Serca2a protein expression was significantly increased in NTG and TG hearts injected with Ad.Ser for up to 6 weeks. Compared to TG-Ad.LacZ hearts, the TG-Ad.Ser hearts showed improved whole heart morphology. Moreover, there was a significant decline in ANF and β-MHC expression. Developed force in isolated papillary muscle from 2- to 3-week-old TG-Ad.Ser hearts was higher and the response to isoproterenol (ISO) improved compared to TG-Ad.LacZ muscles. In situ hemodynamic measurements showed that by 3 months the TG-Ad.Ser hearts also had a significantly improved response to ISO compared to TG-Ad.LacZ hearts. The present study strongly suggests that Serca2a expression should be considered as a potential target for gene therapy in FHC. Moreover, our data imply that development of FHC can be successfully delayed if therapies are started shortly after birth.
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Affiliation(s)
- James R Peña
- Department of Medicine, Section of Cardiology, University of Illinois at Chicago, Chicago, IL 60612, USA
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Scruggs SB, Reisdorph R, Armstrong ML, Warren CM, Reisdorph N, Solaro RJ, Buttrick PM. A novel, in-solution separation of endogenous cardiac sarcomeric proteins and identification of distinct charged variants of regulatory light chain. Mol Cell Proteomics 2010; 9:1804-18. [PMID: 20445002 DOI: 10.1074/mcp.m110.000075] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The molecular conformation of the cardiac myosin motor is modulated by intermolecular interactions among the heavy chain, the light chains, myosin binding protein-C, and titin and is governed by post-translational modifications (PTMs). In-gel digestion followed by LC/MS/MS has classically been applied to identify cardiac sarcomeric PTMs; however, this approach is limited by protein size, pI, and difficulties in peptide extraction. We report a solution-based work flow for global separation of endogenous cardiac sarcomeric proteins with a focus on the regulatory light chain (RLC) in which specific sites of phosphorylation have been unclear. Subcellular fractionation followed by OFFGEL electrophoresis resulted in isolation of endogenous charge variants of sarcomeric proteins, including regulatory and essential light chains, myosin heavy chain, and myosin-binding protein-C of the thick filament. Further purification of RLC using reverse-phase HPLC separation and UV detection enriched for RLC PTMs at the intact protein level and provided a stoichiometric and quantitative assessment of endogenous RLC charge variants. Digestion and subsequent LC/MS/MS unequivocally identified that the endogenous charge variants of cardiac RLC focused in unique OFFGEL electrophoresis fractions were unphosphorylated (78.8%), singly phosphorylated (18.1%), and doubly phosphorylated (3.1%) RLC. The novel aspects of this study are that 1) milligram amounts of endogenous cardiac sarcomeric subproteome were focused with resolution comparable with two-dimensional electrophoresis, 2) separation and quantification of post-translationally modified variants were achieved at the intact protein level, 3) separation of intact high molecular weight thick filament proteins was achieved in solution, and 4) endogenous charge variants of RLC were separated; a novel doubly phosphorylated form was identified in mouse, and singly phosphorylated, singly deamidated, and deamidated/phosphorylated forms were identified and quantified in human non-failing and failing heart samples, thus demonstrating the clinical utility of the method.
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Affiliation(s)
- Sarah B Scruggs
- Department of Physiology and Biophysics, University of Illinois, Chicago, Illinois 60612, USA
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Warren CM, Geenen DL, Helseth DL, Solaro RJ. Sub-Proteomic Fractionation of Rat Cardiac Tissue: Comparing Ischemic Vs Normal Remote Region with In-Solution Based Proteomics. Biophys J 2010. [DOI: 10.1016/j.bpj.2009.12.3942] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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