1
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Abstract
Pumping of the heart is powered by filaments of the motor protein myosin that pull on actin filaments to generate cardiac contraction. In addition to myosin, the filaments contain cardiac myosin-binding protein C (cMyBP-C), which modulates contractility in response to physiological stimuli, and titin, which functions as a scaffold for filament assembly1. Myosin, cMyBP-C and titin are all subject to mutation, which can lead to heart failure. Despite the central importance of cardiac myosin filaments to life, their molecular structure has remained a mystery for 60 years2. Here we solve the structure of the main (cMyBP-C-containing) region of the human cardiac filament using cryo-electron microscopy. The reconstruction reveals the architecture of titin and cMyBP-C and shows how myosin's motor domains (heads) form three different types of motif (providing functional flexibility), which interact with each other and with titin and cMyBP-C to dictate filament architecture and function. The packing of myosin tails in the filament backbone is also resolved. The structure suggests how cMyBP-C helps to generate the cardiac super-relaxed state3; how titin and cMyBP-C may contribute to length-dependent activation4; and how mutations in myosin and cMyBP-C might disturb interactions, causing disease5,6. The reconstruction resolves past uncertainties and integrates previous data on cardiac muscle structure and function. It provides a new paradigm for interpreting structural, physiological and clinical observations, and for the design of potential therapeutic drugs.
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Affiliation(s)
- Debabrata Dutta
- Division of Cell Biology and Imaging, Department of Radiology, University of Massachusetts Chan Medical School, Worcester, MA, USA.
| | - Vu Nguyen
- Division of Cell Biology and Imaging, Department of Radiology, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - Kenneth S Campbell
- Department of Physiology and Division of Cardiovascular Medicine, University of Kentucky, Lexington, KY, USA
| | - Raúl Padrón
- Division of Cell Biology and Imaging, Department of Radiology, University of Massachusetts Chan Medical School, Worcester, MA, USA.
| | - Roger Craig
- Division of Cell Biology and Imaging, Department of Radiology, University of Massachusetts Chan Medical School, Worcester, MA, USA.
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2
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Ma W, Lee KH, Delligatti CE, Davis MT, Zheng Y, Gong H, Kirk JA, Craig R, Irving T. The structural and functional integrities of porcine myocardium are mostly preserved by cryopreservation. J Gen Physiol 2023; 155:e202313345. [PMID: 37398997 DOI: 10.1085/jgp.202313345] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Revised: 05/05/2023] [Accepted: 06/21/2023] [Indexed: 07/04/2023] Open
Abstract
Structural and functional studies of heart muscle are important to gain insights into the physiological bases of cardiac muscle contraction and the pathological bases of heart disease. While fresh muscle tissue works best for these kinds of studies, this is not always practical to obtain, especially for heart tissue from large animal models and humans. Conversely, tissue banks of frozen human hearts are available and could be a tremendous resource for translational research. It is not well understood, however, how liquid nitrogen freezing and cryostorage may impact the structural integrity of myocardium from large mammals. In this study, we directly compared the structural and functional integrity of never-frozen to previously frozen porcine myocardium to investigate the consequences of freezing and cryostorage. X-ray diffraction measurements from hydrated tissue under near-physiological conditions and electron microscope images from chemically fixed porcine myocardium showed that prior freezing has only minor effects on structural integrity of the muscle. Furthermore, mechanical studies similarly showed no significant differences in contractile capabilities of porcine myocardium with and without freezing and cryostorage. These results demonstrate that liquid nitrogen preservation is a practical approach for structural and functional studies of myocardium.
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Affiliation(s)
- Weikang Ma
- BioCAT, Department of Biology, Illinois Institute of Technology, Chicago, IL, USA
| | - Kyoung Hwan Lee
- Electron Microscopy Facility, UMass Chan Medical School, Worcester, MA, USA
| | - Christine E Delligatti
- Department of Cell and Molecular Physiology, Loyola University Chicago, Chicago, IL, USA
| | - M Therese Davis
- Department of Cell and Molecular Physiology, Loyola University Chicago, Chicago, IL, USA
| | - Yahan Zheng
- College of Basic Medical Sciences, Dalian Medical University , Dalian, China
| | - Henry Gong
- BioCAT, Department of Biology, Illinois Institute of Technology, Chicago, IL, USA
| | - Jonathan A Kirk
- Department of Cell and Molecular Physiology, Loyola University Chicago, Chicago, IL, USA
| | - Roger Craig
- Division of Cell Biology and Imaging, Department of Radiology, University of Massachusetts Medical School, Worcester, MA, USA
| | - Thomas Irving
- BioCAT, Department of Biology, Illinois Institute of Technology, Chicago, IL, USA
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3
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Ruggles T, Gilliland W, Noell P, Craig R, Fitzgerald K, Carroll J. Local Stress Measurements in Polycrystalline Metallic Tensile Specimens Using High Resolution EBSD. Microsc Microanal 2023; 29:96-97. [PMID: 37613449 DOI: 10.1093/micmic/ozad067.041] [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] [Subscribe] [Scholar Register] [Indexed: 08/25/2023]
Affiliation(s)
- T Ruggles
- Sandia National Laboratories, Material, Physical, and Chemical Sciences Center, Albuquerque, NM, United States
| | - W Gilliland
- Sandia National Laboratories, Material, Physical, and Chemical Sciences Center, Albuquerque, NM, United States
| | - P Noell
- Sandia National Laboratories, Material, Physical, and Chemical Sciences Center, Albuquerque, NM, United States
| | - R Craig
- Sandia National Laboratories, Material, Physical, and Chemical Sciences Center, Albuquerque, NM, United States
| | - K Fitzgerald
- Sandia National Laboratories, Material, Physical, and Chemical Sciences Center, Albuquerque, NM, United States
| | - J Carroll
- Sandia National Laboratories, Material, Physical, and Chemical Sciences Center, Albuquerque, NM, United States
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4
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Abstract
Pumping of the heart is powered by filaments of the motor protein myosin, which pull on actin filaments to generate cardiac contraction. In addition to myosin, the filaments contain cardiac myosin-binding protein C (cMyBP-C), which modulates contractility in response to physiological stimuli, and titin, which functions as a scaffold for filament assembly 1 . Myosin, cMyBP-C and titin are all subject to mutation, which can lead to heart failure. Despite the central importance of cardiac myosin filaments to life, their molecular structure has remained a mystery for 60 years 2 . Here, we have solved the structure of the main (cMyBP-C-containing) region of the human cardiac filament to 6 Å resolution by cryo-EM. The reconstruction reveals the architecture of titin and cMyBP-C for the first time, and shows how myosin's motor domains (heads) form 3 different types of motif (providing functional flexibility), which interact with each other and with specific domains of titin and cMyBP-C to dictate filament architecture and regulate function. A novel packing of myosin tails in the filament backbone is also resolved. The structure suggests how cMyBP-C helps generate the cardiac super-relaxed state 3 , how titin and cMyBP-C may contribute to length-dependent activation 4 , and how mutations in myosin and cMyBP-C might disrupt interactions, causing disease 5, 6 . A similar structure is likely in vertebrate skeletal myosin filaments. The reconstruction resolves past uncertainties, and integrates previous data on cardiac muscle structure and function. It provides a new paradigm for interpreting structural, physiological and clinical observations, and for the design of potential therapeutic drugs.
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5
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Dutta D, Nguyen V, Padron R, Craig R. cryo-EM structure of tarantula myosin filament: Implications for analysis of myopathy mutations. Biophys J 2023; 122:118a. [PMID: 36782515 DOI: 10.1016/j.bpj.2022.11.810] [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: 02/12/2023] Open
Affiliation(s)
- Debabrata Dutta
- Radiology, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - Vu Nguyen
- Radiology, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - Raul Padron
- Radiology, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - Roger Craig
- Radiology, University of Massachusetts Chan Medical School, Worcester, MA, USA
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6
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Rasicci DV, Tiwari P, Bodt SML, Desetty R, Sadler FR, Sivaramakrishnan S, Craig R, Yengo CM. Dilated cardiomyopathy mutation E525K in human beta-cardiac myosin stabilizes the interacting-heads motif and super-relaxed state of myosin. eLife 2022; 11:77415. [PMID: 36422472 PMCID: PMC9691020 DOI: 10.7554/elife.77415] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Accepted: 11/08/2022] [Indexed: 11/25/2022] Open
Abstract
The auto-inhibited, super-relaxed (SRX) state of cardiac myosin is thought to be crucial for regulating contraction, relaxation, and energy conservation in the heart. We used single ATP turnover experiments to demonstrate that a dilated cardiomyopathy (DCM) mutation (E525K) in human beta-cardiac myosin increases the fraction of myosin heads in the SRX state (with slow ATP turnover), especially in physiological ionic strength conditions. We also utilized FRET between a C-terminal GFP tag on the myosin tail and Cy3ATP bound to the active site of the motor domain to estimate the fraction of heads in the closed, interacting-heads motif (IHM); we found a strong correlation between the IHM and SRX state. Negative stain electron microscopy and 2D class averaging of the construct demonstrated that the E525K mutation increased the fraction of molecules adopting the IHM. Overall, our results demonstrate that the E525K DCM mutation may reduce muscle force and power by stabilizing the auto-inhibited SRX state. Our studies also provide direct evidence for a correlation between the SRX biochemical state and the IHM structural state in cardiac muscle myosin. Furthermore, the E525 residue may be implicated in crucial electrostatic interactions that modulate this conserved, auto-inhibited conformation of myosin.
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Affiliation(s)
- David V Rasicci
- Department of Cellular and Molecular Physiology, Penn State College of Medicine, Hershey, United States
| | - Prince Tiwari
- Department of Radiology, Division of Cell Biology and Imaging, UMass Chan Medical School, Worcester, United States
| | - Skylar M L Bodt
- Department of Cellular and Molecular Physiology, Penn State College of Medicine, Hershey, United States
| | - Rohini Desetty
- Department of Cellular and Molecular Physiology, Penn State College of Medicine, Hershey, United States
| | - Fredrik R Sadler
- Department of Genetics, Cell Biology, and Development, University of Minnesota Twin Cities, Minneapolis, United States
| | - Sivaraj Sivaramakrishnan
- Department of Genetics, Cell Biology, and Development, University of Minnesota Twin Cities, Minneapolis, United States
| | - Roger Craig
- Department of Radiology, Division of Cell Biology and Imaging, UMass Chan Medical School, Worcester, United States
| | - Christopher M Yengo
- Department of Cellular and Molecular Physiology, Penn State College of Medicine, Hershey, United States
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7
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Abstract
Under relaxing conditions, the two heads of myosin II interact with each other and with the proximal part (S2) of the myosin tail, establishing the interacting-heads motif (IHM), found in myosin molecules and thick filaments of muscle and nonmuscle cells. The IHM is normally thought of as a single, unique structure, but there are several variants. In the simplest ("canonical") IHM, occurring in most relaxed thick filaments and in heavy meromyosin, the interacting heads bend back and interact with S2, and the motif lies parallel to the filament surface. In one variant, occurring in insect indirect flight muscle, there is no S2-head interaction and the motif is perpendicular to the filament. In a second variant, found in smooth and nonmuscle single myosin molecules in their inhibited (10S) conformation, S2 is shifted ∼20 Å from the canonical form and the tail folds twice and wraps around the interacting heads. These molecule and filament IHM variants have important energetic and pathophysiological consequences. (1) The canonical motif, with S2-head interaction, correlates with the super-relaxed (SRX) state of myosin. The absence of S2-head interaction in insects may account for the lower stability of this IHM and apparent absence of SRX in indirect flight muscle, contributing to the quick initiation of flight in insects. (2) The ∼20 Å shift of S2 in 10S myosin molecules means that S2-head interactions are different from those in the canonical IHM. This variant therefore cannot be used to analyze the impact of myosin mutations on S2-head interactions that occur in filaments, as has been proposed. It can be used, instead, to analyze the structural impact of mutations in smooth and nonmuscle myosin.
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Affiliation(s)
- Raúl Padrón
- Division of Cell Biology and Imaging, Department of Radiology, University of Massachusetts Chan Medical School, Worcester, MA,Correspondence to Raul Padron:
| | - Debabrata Dutta
- Division of Cell Biology and Imaging, Department of Radiology, University of Massachusetts Chan Medical School, Worcester, MA
| | - Roger Craig
- Division of Cell Biology and Imaging, Department of Radiology, University of Massachusetts Chan Medical School, Worcester, MA
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8
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Koubassova NA, Tsaturyan AK, Bershitsky SY, Ferenczi MA, Padrón R, Craig R. Interacting-Heads Motif Explains the X-Ray Diffraction Pattern of Relaxed Vertebrate Skeletal Muscle. Biophys J 2022; 121:1354-1366. [PMID: 35318005 PMCID: PMC9072692 DOI: 10.1016/j.bpj.2022.03.023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Revised: 01/25/2022] [Accepted: 03/17/2022] [Indexed: 11/19/2022] Open
Abstract
Electron microscopy (EM) shows that myosin heads in thick filaments isolated from striated muscles interact with each other and with the myosin tail under relaxing conditions. This "interacting-heads motif" (IHM) is highly conserved across the animal kingdom and is thought to be the basis of the super-relaxed state. However, a recent X-ray modeling study concludes, contrary to expectation, that the IHM is not present in relaxed intact muscle. We propose that this conclusion results from modeling with a thick filament 3D reconstruction in which the myosin heads have radially collapsed onto the thick filament backbone, not from absence of the IHM. Such radial collapse, by about 3-4 nm, is well established in EM studies of negatively stained myosin filaments, on which the reconstruction was based. We have tested this idea by carrying out similar X-ray modeling and determining the effect of the radial position of the heads on the goodness of fit to the X-ray pattern. We find that, when the IHM is modeled into a thick filament at a radius 3-4 nm greater than that modeled in the recent study, there is good agreement with the X-ray pattern. When the original (collapsed) radial position is used, the fit is poor, in agreement with that study. We show that modeling of the low-angle region of the X-ray pattern is relatively insensitive to the conformation of the myosin heads but very sensitive to their radial distance from the filament axis. We conclude that the IHM is sufficient to explain the X-ray diffraction pattern of intact muscle when placed at the appropriate radius.
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Affiliation(s)
| | | | - Sergey Y Bershitsky
- Institute of Immunology and Physiology, Russian Academy of Sciences, Yekaterinburg, Russia
| | - Michael A Ferenczi
- Brunel Medical School, College of Health, Medicine and Life Sciences, Brunel University London, Uxbridge, UK
| | - Raúl Padrón
- Division of Cell Biology and Imaging, Department of Radiology, University of Massachusetts Chan Medical School, Worcester, Massachusetts
| | - Roger Craig
- Division of Cell Biology and Imaging, Department of Radiology, University of Massachusetts Chan Medical School, Worcester, Massachusetts.
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9
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Abstract
Super-relaxation is a state of muscle thick filaments in which ATP turnover by myosin is much slower than that of myosin II in solution. This inhibited state, in equilibrium with a faster (relaxed) state, is ubiquitous and thought to be fundamental to muscle function, acting as a mechanism for switching off energy-consuming myosin motors when they are not being used. The structural basis of super-relaxation is usually taken to be a motif formed by myosin in which the two heads interact with each other and with the proximal tail forming an interacting-heads motif, which switches the heads off. However, recent studies show that even isolated myosin heads can exhibit this slow rate. Here, we review the role of head interactions in creating the super-relaxed state and show how increased numbers of interactions in thick filaments underlie the high levels of super-relaxation found in intact muscle. We suggest how a third, even more inhibited, state of myosin (a hyper-relaxed state) seen in certain species results from additional interactions involving the heads. We speculate on the relationship between animal lifestyle and level of super-relaxation in different species and on the mechanism of formation of the super-relaxed state. We also review how super-relaxed thick filaments are activated and how the super-relaxed state is modulated in healthy and diseased muscles.
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Affiliation(s)
- Roger Craig
- Division of Cell Biology and Imaging, Department of Radiology, University of Massachusetts Chan Medical School, Worcester, MA
| | - Raúl Padrón
- Division of Cell Biology and Imaging, Department of Radiology, University of Massachusetts Chan Medical School, Worcester, MA
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10
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Lynch TL, Kumar M, McNamara JW, Kuster DWD, Sivaguru M, Singh RR, Previs MJ, Lee KH, Kuffel G, Zilliox MJ, Lin BL, Ma W, Gibson AM, Blaxall BC, Nieman ML, Lorenz JN, Leichter DM, Leary OP, Janssen PML, de Tombe PP, Gilbert RJ, Craig R, Irving T, Warshaw DM, Sadayappan S. Amino terminus of cardiac myosin binding protein-C regulates cardiac contractility. J Mol Cell Cardiol 2021; 156:33-44. [PMID: 33781820 DOI: 10.1016/j.yjmcc.2021.03.009] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [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: 06/15/2020] [Revised: 03/21/2021] [Accepted: 03/22/2021] [Indexed: 12/12/2022]
Abstract
Phosphorylation of cardiac myosin binding protein-C (cMyBP-C) regulates cardiac contraction through modulation of actomyosin interactions mediated by the protein's amino terminal (N')-region (C0-C2 domains, 358 amino acids). On the other hand, dephosphorylation of cMyBP-C during myocardial injury results in cleavage of the 271 amino acid C0-C1f region and subsequent contractile dysfunction. Yet, our current understanding of amino terminus region of cMyBP-C in the context of regulating thin and thick filament interactions is limited. A novel cardiac-specific transgenic mouse model expressing cMyBP-C, but lacking its C0-C1f region (cMyBP-C∆C0-C1f), displayed dilated cardiomyopathy, underscoring the importance of the N'-region in cMyBP-C. Further exploring the molecular basis for this cardiomyopathy, in vitro studies revealed increased interfilament lattice spacing and rate of tension redevelopment, as well as faster actin-filament sliding velocity within the C-zone of the transgenic sarcomere. Moreover, phosphorylation of the unablated phosphoregulatory sites was increased, likely contributing to normal sarcomere morphology and myoarchitecture. These results led us to hypothesize that restoration of the N'-region of cMyBP-C would return actomyosin interaction to its steady state. Accordingly, we administered recombinant C0-C2 (rC0-C2) to permeabilized cardiomyocytes from transgenic, cMyBP-C null, and human heart failure biopsies, and we found that normal regulation of actomyosin interaction and contractility was restored. Overall, these data provide a unique picture of selective perturbations of the cardiac sarcomere that either lead to injury or adaptation to injury in the myocardium.
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Affiliation(s)
- Thomas L Lynch
- Department of Cell and Molecular Physiology, Loyola University Chicago, Maywood, IL 60153, USA
| | - Mohit Kumar
- Department of Cell and Molecular Physiology, Loyola University Chicago, Maywood, IL 60153, USA; Heart, Lung and Vascular Institute, Division of Cardiovascular Health and Disease, Department of Internal Medicine, University of Cincinnati, Cincinnati, OH 45267, USA
| | - James W McNamara
- Heart, Lung and Vascular Institute, Division of Cardiovascular Health and Disease, Department of Internal Medicine, University of Cincinnati, Cincinnati, OH 45267, USA
| | - Diederik W D Kuster
- Department of Cell and Molecular Physiology, Loyola University Chicago, Maywood, IL 60153, USA; Department of Physiology, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam Cardiovascular Sciences, Amsterdam, the Netherlands
| | - Mayandi Sivaguru
- Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Rohit R Singh
- Heart, Lung and Vascular Institute, Division of Cardiovascular Health and Disease, Department of Internal Medicine, University of Cincinnati, Cincinnati, OH 45267, USA
| | - Michael J Previs
- Department of Molecular Physiology and Biophysics, Cardiovascular Research Institute, University of Vermont, Burlington, VT 05405, USA
| | - Kyoung Hwan Lee
- Division of Cell Biology and Imaging, Department of Radiology, University of Massachusetts Medical School, Worcester, MA 01655, USA
| | - Gina Kuffel
- Department of Public Health Sciences, Loyola University Chicago, Maywood, IL 60153, USA
| | - Michael J Zilliox
- Department of Public Health Sciences, Loyola University Chicago, Maywood, IL 60153, USA
| | - Brian Leei Lin
- Department of Cell and Molecular Physiology, Loyola University Chicago, Maywood, IL 60153, USA
| | - Weikang Ma
- Center for Synchrotron Radiation Research and Instrumentation and Department of Biological Sciences, Illinois Institute of Technology, Chicago, IL 60616, USA
| | - Aaron M Gibson
- Department of Pediatrics, Heart Institute, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, 45229, USA
| | - Burns C Blaxall
- Department of Pediatrics, Heart Institute, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, 45229, USA
| | - Michelle L Nieman
- Department of Pharmacology and Systems Physiology, University of Cincinnati College of Medicine, Cincinnati, OH, USA
| | - John N Lorenz
- Department of Pharmacology and Systems Physiology, University of Cincinnati College of Medicine, Cincinnati, OH, USA
| | - Dana M Leichter
- Research Service, Providence VA Medical Center, Providence, RI 02908, USA
| | - Owen P Leary
- Research Service, Providence VA Medical Center, Providence, RI 02908, USA
| | - Paul M L Janssen
- Department of Physiology and Cell Biology, The Ohio State University, Columbus, OH 43210, USA
| | - Pieter P de Tombe
- Department of Cell and Molecular Physiology, Loyola University Chicago, Maywood, IL 60153, USA; Department of Physiology, University of Illinois at Chicago, Chicago 60612, USA; Phymedexp, Université de Montpellier, Inserm, CNRS, Montpellier, France
| | - Richard J Gilbert
- Research Service, Providence VA Medical Center, Providence, RI 02908, USA
| | - Roger Craig
- Division of Cell Biology and Imaging, Department of Radiology, University of Massachusetts Medical School, Worcester, MA 01655, USA
| | - Thomas Irving
- Center for Synchrotron Radiation Research and Instrumentation and Department of Biological Sciences, Illinois Institute of Technology, Chicago, IL 60616, USA
| | - David M Warshaw
- Department of Molecular Physiology and Biophysics, Cardiovascular Research Institute, University of Vermont, Burlington, VT 05405, USA
| | - Sakthivel Sadayappan
- Department of Cell and Molecular Physiology, Loyola University Chicago, Maywood, IL 60153, USA; Heart, Lung and Vascular Institute, Division of Cardiovascular Health and Disease, Department of Internal Medicine, University of Cincinnati, Cincinnati, OH 45267, USA.
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11
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Ma W, Duno-Miranda S, Irving T, Craig R, Padrón R. Relaxed tarantula skeletal muscle has two ATP energy-saving mechanisms. J Gen Physiol 2021; 153:211706. [PMID: 33480967 PMCID: PMC7822627 DOI: 10.1085/jgp.202012780] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Accepted: 12/22/2020] [Indexed: 12/15/2022] Open
Abstract
Myosin molecules in the relaxed thick filaments of striated muscle have a helical arrangement in which the heads of each molecule interact with each other, forming the interacting-heads motif (IHM). In relaxed mammalian skeletal muscle, this helical ordering occurs only at temperatures >20°C and is disrupted when temperature is decreased. Recent x-ray diffraction studies of live tarantula skeletal muscle have suggested that the two myosin heads of the IHM (blocked heads [BHs] and free heads [FHs]) have very different roles and dynamics during contraction. Here, we explore temperature-induced changes in the BHs and FHs in relaxed tarantula skeletal muscle. We find a change with decreasing temperature that is similar to that in mammals, while increasing temperature induces a different behavior in the heads. At 22.5°C, the BHs and FHs containing ADP.Pi are fully helically organized, but they become progressively disordered as temperature is lowered or raised. Our interpretation suggests that at low temperature, while the BHs remain ordered the FHs become disordered due to transition of the heads to a straight conformation containing Mg.ATP. Above 27.5°C, the nucleotide remains as ADP.Pi, but while BHs remain ordered, half of the FHs become progressively disordered, released semipermanently at a midway distance to the thin filaments while the remaining FHs are docked as swaying heads. We propose a thermosensing mechanism for tarantula skeletal muscle to explain these changes. Our results suggest that tarantula skeletal muscle thick filaments, in addition to having a superrelaxation–based ATP energy-saving mechanism in the range of 8.5–40°C, also exhibit energy saving at lower temperatures (<22.5°C), similar to the proposed refractory state in mammals.
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Affiliation(s)
- Weikang Ma
- Biophysics Collaborative Access Team, Department of Biological Sciences, Illinois Institute of Technology, Chicago, IL
| | - Sebastian Duno-Miranda
- Department of Molecular Physiology and Biophysics, Cardiovascular Research Institute, University of Vermont, Burlington, VT
| | - Thomas Irving
- Biophysics Collaborative Access Team, Department of Biological Sciences, Illinois Institute of Technology, Chicago, IL
| | - Roger Craig
- Division of Cell Biology and Imaging, Department of Radiology, University of Massachusetts Medical School, Worcester, MA
| | - Raúl Padrón
- Division of Cell Biology and Imaging, Department of Radiology, University of Massachusetts Medical School, Worcester, MA
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12
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Rahmanseresht S, Lee KH, O'Leary TS, McNamara JW, Sadayappan S, Robbins J, Warshaw DM, Craig R, Previs MJ. The N terminus of myosin-binding protein C extends toward actin filaments in intact cardiac muscle. J Gen Physiol 2021; 153:211744. [PMID: 33528507 PMCID: PMC7852460 DOI: 10.1085/jgp.202012726] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Revised: 10/23/2020] [Accepted: 12/03/2020] [Indexed: 12/31/2022] Open
Abstract
Myosin and actin filaments are highly organized within muscle sarcomeres. Myosin-binding protein C (MyBP-C) is a flexible, rod-like protein located within the C-zone of the sarcomere. The C-terminal domain of MyBP-C is tethered to the myosin filament backbone, and the N-terminal domains are postulated to interact with actin and/or the myosin head to modulate filament sliding. To define where the N-terminal domains of MyBP-C are localized in the sarcomere of active and relaxed mouse myocardium, the relative positions of the N terminus of MyBP-C and actin were imaged in fixed muscle samples using super-resolution fluorescence microscopy. The resolution of the imaging was enhanced by particle averaging. The images demonstrate that the position of the N terminus of MyBP-C is biased toward the actin filaments in both active and relaxed muscle preparations. Comparison of the experimental images with images generated in silico, accounting for known binding partner interactions, suggests that the N-terminal domains of MyBP-C may bind to actin and possibly the myosin head but only when the myosin head is in the proximity of an actin filament. These physiologically relevant images help define the molecular mechanism by which the N-terminal domains of MyBP-C may search for, and capture, molecular binding partners to tune cardiac contractility.
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Affiliation(s)
- Sheema Rahmanseresht
- Department of Molecular Physiology and Biophysics, Cardiovascular Research Institute, University of Vermont, Burlington, VT
| | - Kyoung H Lee
- Division of Cell Biology and Imaging, Department of Radiology, University of Massachusetts Medical School, Worcester, MA
| | - Thomas S O'Leary
- Department of Molecular Physiology and Biophysics, Cardiovascular Research Institute, University of Vermont, Burlington, VT
| | - James W McNamara
- Heart, Lung and Vascular Institute, Department of Internal Medicine, Division of Cardiovascular Health and Disease, University of Cincinnati, Cincinnati, OH
| | - Sakthivel Sadayappan
- Heart, Lung and Vascular Institute, Department of Internal Medicine, Division of Cardiovascular Health and Disease, University of Cincinnati, Cincinnati, OH
| | - Jeffrey Robbins
- Department of Pediatrics and the Heart Institute, Cincinnati Children's Hospital Medical Center, Cincinnati, OH
| | - David M Warshaw
- Department of Molecular Physiology and Biophysics, Cardiovascular Research Institute, University of Vermont, Burlington, VT
| | - Roger Craig
- Division of Cell Biology and Imaging, Department of Radiology, University of Massachusetts Medical School, Worcester, MA
| | - Michael J Previs
- Department of Molecular Physiology and Biophysics, Cardiovascular Research Institute, University of Vermont, Burlington, VT
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13
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Yang S, Tiwari P, Lee KH, Sato O, Ikebe M, Padrón R, Craig R. Cryo-EM structure of the inhibited (10S) form of myosin II. Nature 2020; 588:521-525. [PMID: 33268893 PMCID: PMC7746622 DOI: 10.1038/s41586-020-3007-0] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Accepted: 10/01/2020] [Indexed: 01/14/2023]
Abstract
Myosin II is the motor protein responsible for contractility in muscle and nonmuscle cells1. The molecule has two identical heads attached to an elongated tail, and can exist in two conformations: 10S and 6S, named for their sedimentation coefficients2,3. The 6S conformation has an extended tail and assembles into polymeric filaments, which pull on actin filaments to generate force and motion. In 10S myosin, the tail is folded into three segments and the heads bend back and interact with each other and the tail3-7, creating a compact conformation, in which ATPase activity, actin activation and filament assembly are all highly inhibited7,8. This switched-off structure appears to function as a key energy-conserving storage molecule in muscle and nonmuscle cells9-12, which can be activated to form functional filaments as needed13 – but the mechanism of its inhibition is not understood. Here we have solved the structure of smooth muscle 10S myosin to a global resolution of 4.3 Å by cryo-EM, revealing near-atomic level details of its structure for the first time. The reconstruction provides a new understanding of the head and tail regions of the molecule and of the key intramolecular contacts that cause inhibition. Our results suggest an atomic model for the off-state of myosin II, for its activation and unfolding by phosphorylation, and for understanding the clustering of disease-causing mutations near sites of intramolecular interaction.
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Affiliation(s)
- Shixin Yang
- Division of Cell Biology and Imaging, Department of Radiology, University of Massachusetts Medical School, Worcester, MA, USA.,Cryo-EM Shared Resources, Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
| | - Prince Tiwari
- Division of Cell Biology and Imaging, Department of Radiology, University of Massachusetts Medical School, Worcester, MA, USA
| | - Kyoung Hwan Lee
- Division of Cell Biology and Imaging, Department of Radiology, University of Massachusetts Medical School, Worcester, MA, USA.,Massachusetts Facility for High-Resolution Electron Cryo-microscopy, University of Massachusetts Medical School, Worcester, MA, USA
| | - Osamu Sato
- Department of Cellular and Molecular Biology, University of Texas Health Science Center at Tyler, Tyler, TX, USA
| | - Mitsuo Ikebe
- Department of Cellular and Molecular Biology, University of Texas Health Science Center at Tyler, Tyler, TX, USA
| | - Raúl Padrón
- Division of Cell Biology and Imaging, Department of Radiology, University of Massachusetts Medical School, Worcester, MA, USA
| | - Roger Craig
- Division of Cell Biology and Imaging, Department of Radiology, University of Massachusetts Medical School, Worcester, MA, USA.
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14
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Singh A, Behl P, Craig R. Metastatic Prostate Adenocarcinoma in Rectal Polyp: A Rare Clinical Presentation. Am J Clin Pathol 2020. [DOI: 10.1093/ajcp/aqaa161.142] [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: 11/12/2022] Open
Abstract
Abstract
Introduction/Objective
Prostate cancer is known to metastasize to bone, lymph node, lungs, liver, and brain, with the GI tract being an uncommon site of metastasis. More commonly, prostate adenocarcinoma involves GI tract by direct colonic extension. Interestingly, few cases have been reported with metastasis presenting as a GI polyp.
Methods
We herein report a case of 69-year-old African American male who was diagnosed with metastasis of prostate adenocarcinoma presenting as rectal polyp. The patient originally presented with lower urinary tract symptoms. Further examination revealed PSA level of 220. The patient underwent TRUS-guided prostate biopsy which showed prostate adenocarcinoma with Gleason score of 9 (grade group 5). Follow-up CT and radioisotope scans showed direct extension of prostate lesion into bladder, seminal vesicle and rectum. Metastases were noted to right lesser trochanter, L5 vertebra and retroperitoneal lymph nodes. Colonoscopy was performed 1 month after prostate biopsy due to abnormal CT finding of rectal wall thickening. Endoscopy found a single 0.5 mm sessile polyp which was resected by cold snare polypectomy.
Results
Microscopically, a nodule of tubular glands arranged back to back containing pleomorphic cells with large nuclei, prominent nucleoli, and vacuolated cytoplasm was seen underlying normal colonic mucosa. The malignant cells expressed prostate specific antigen (PSA) and phosphate specific acid phosphatase (PSAP). It was negative for CK7 and CDX2, rendering a diagnosis of metastatic prostate adenocarcinoma. Patient is currently receiving androgen deprivation treatment and enzalutamide with future plans for external beam radiation. The germline alteration testing was positive for BRCA2 which is associated with increased risk of prostate cancer.
Conclusion
Albeit rare, it’s important for pathologists to be aware of this entity presenting uncommonly as a rectal polyp, particularly given the history of prostate adenocarcinoma which could be mistaken for colonic adenocarcinoma. In rare cases, tumor seeding following TRUS-guided prostate biopsy has also been implicated.
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Affiliation(s)
- A Singh
- Department of Pathology & Laboratory Medicine, Tulane University School of Medicine, New Orleans, Louisiana, UNITED STATES
| | - P Behl
- Department of Pathology & Laboratory Medicine, Tulane University School of Medicine, New Orleans, Louisiana, UNITED STATES
| | - R Craig
- Department of Pathology & Laboratory Medicine, Tulane University School of Medicine, New Orleans, Louisiana, UNITED STATES
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15
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Okonkwo INC, Howie A, Parry C, Shelton CL, Cobley S, Craig R, Permall N, El-Sheikha SH, Herbert N, Arnold P. The safety of paediatric surgery between COVID-19 surges: an observational study. Anaesthesia 2020; 75:1605-1613. [PMID: 32955100 PMCID: PMC7537528 DOI: 10.1111/anae.15264] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/09/2020] [Indexed: 12/20/2022]
Abstract
Despite the ongoing coronavirus disease 2019 (COVID‐19) pandemic, elective paediatric surgery must continue safely through the first, second and subsequent waves of disease. This study presents outcome data from a children's hospital in north‐west England, the region with the highest prevalence of COVID‐19 in England. Children and young people undergoing elective surgery isolated within their household for 14 days, then presented for real‐time reverse transcriptase polymerase chain reaction testing for severe acute respiratory syndrome coronavirus disease‐2 (SARS‐CoV‐2) within 72 h of their procedure (or rapid testing within 24 h in high‐risk cases), and completed a screening questionnaire on admission. Planned surgery resumed on 26 May 2020; in the four subsequent weeks, there were 197 patients for emergency and 501 for elective procedures. A total of 488 out of 501 (97.4%) elective admissions proceeded, representing a 2.6% COVID‐19‐related cancellation rate. There was no difference in the incidence of SARS‐CoV‐2 among children and young people who had or had not isolated for 14 days (p > 0.99). One out of 685 (0.1%) children who had surgery re‐presented to the hospital with symptoms potentially consistent with SARS‐CoV‐2 within 14 days of surgery. Outcomes were similar to those in the same time period in 2019 for length of stay (p = 1.0); unplanned critical care admissions (p = 0.59); and 14‐day hospital re‐admission (p = 0.17). However, the current cohort were younger (p = 0.037); of increased complexity (p < 0.001) and underwent more complex surgery (p < 0.001). The combined use of household self‐isolation, testing and screening questionnaires has allowed the re‐initiation of elective paediatric surgery at high volume while maintaining pre‐COVID‐19 outcomes in children and young people undergoing surgery. This may provide a model for addressing the ongoing challenges posed by COVID‐19, as well as future pandemics.
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Affiliation(s)
- I N C Okonkwo
- Jackson Rees Department of Anaesthesia, Alder Hey Children's NHS Foundation Trust, Liverpool, UK
| | - A Howie
- Jackson Rees Department of Anaesthesia, Alder Hey Children's NHS Foundation Trust, Liverpool, UK
| | - C Parry
- Microbiology, Alder Hey Children's NHS Foundation Trust, Liverpool, UK.,Clinical Infection, Microbiology and Immunology, University of Liverpool, Liverpool, UK
| | - C L Shelton
- Department of Anaesthesia, Wythenshawe Hospital, Manchester University NHS Foundation Trust, Manchester, UK.,Lancaster Medical School, Faculty of Health and Medicine, Lancaster University, Lancaster, UK
| | - S Cobley
- Alder Hey Children's NHS Foundation Trust, Liverpool, UK
| | - R Craig
- Jackson Rees Department of Anaesthesia, Alder Hey Children's NHS Foundation Trust, Liverpool, UK
| | - N Permall
- Alder Hey Children's NHS Foundation Trust, Liverpool, UK
| | - S H El-Sheikha
- Alder Hey Children's NHS Foundation Trust, Liverpool, UK
| | - N Herbert
- Alder Hey Children's NHS Foundation Trust, Liverpool, UK
| | - P Arnold
- Jackson Rees Department of Anaesthesia, Alder Hey Children's NHS Foundation Trust, Liverpool, UK
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16
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Kuster DWD, Lynch TL, Barefield DY, Sivaguru M, Kuffel G, Zilliox MJ, Lee KH, Craig R, Namakkal-Soorappan R, Sadayappan S. Altered C10 domain in cardiac myosin binding protein-C results in hypertrophic cardiomyopathy. Cardiovasc Res 2020; 115:1986-1997. [PMID: 31050699 DOI: 10.1093/cvr/cvz111] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [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: 12/20/2018] [Revised: 04/04/2019] [Accepted: 04/25/2019] [Indexed: 12/12/2022] Open
Abstract
AIMS A 25-base pair deletion in the cardiac myosin binding protein-C (cMyBP-C) gene (MYBPC3), proposed to skip exon 33, modifies the C10 domain (cMyBP-CΔC10mut) and is associated with hypertrophic cardiomyopathy (HCM) and heart failure, affecting approximately 100 million South Asians. However, the molecular mechanisms underlying the pathogenicity of cMyBP-CΔC10mutin vivo are unknown. We hypothesized that expression of cMyBP-CΔC10mut exerts a poison polypeptide effect leading to improper assembly of cardiac sarcomeres and the development of HCM. METHODS AND RESULTS To determine whether expression of cMyBP-CΔC10mut is sufficient to cause HCM and contractile dysfunction in vivo, we generated transgenic (TG) mice having cardiac-specific protein expression of cMyBP-CΔC10mut at approximately half the level of endogenous cMyBP-C. At 12 weeks of age, significant hypertrophy was observed in TG mice expressing cMyBP-CΔC10mut (heart weight/body weight ratio: 4.43 ± 0.11 mg/g non-transgenic (NTG) vs. 5.34 ± 0.25 mg/g cMyBP-CΔC10mut, P < 0.05). Furthermore, haematoxylin and eosin, Masson's trichrome staining, as well as second-harmonic generation imaging revealed the presence of significant fibrosis and a greater relative nuclear area in cMyBP-CΔC10mut hearts compared with NTG controls. M-mode echocardiography analysis revealed hypercontractile hearts (EF: 53.4%±2.9% NTG vs. 66.4% ± 4.7% cMyBP-CΔC10mut; P < 0.05) and early diastolic dysfunction (E/E': 28.7 ± 3.7 NTG vs. 46.3 ± 8.4 cMyBP-CΔC10mut; P < 0.05), indicating the presence of an HCM phenotype. To assess whether these changes manifested at the myofilament level, contractile function of single skinned cardiomyocytes was measured. Preserved maximum force generation and increased Ca2+-sensitivity of force generation were observed in cardiomyocytes from cMyBP-CΔC10mut mice compared with NTG controls (EC50: 3.6 ± 0.02 µM NTG vs. 2.90 ± 0.01 µM cMyBP-CΔC10mut; P < 0.0001). CONCLUSION Expression of cMyBP-C protein with a modified C10 domain is sufficient to cause contractile dysfunction and HCM in vivo.
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Affiliation(s)
- Diederik W D Kuster
- Cell and Molecular Physiology, Loyola University Chicago, Maywood, IL, USA.,Department of Physiology, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam Cardiovascular Sciences, Amsterdam, Netherlands
| | - Thomas L Lynch
- Cell and Molecular Physiology, Loyola University Chicago, Maywood, IL, USA
| | - David Y Barefield
- Cell and Molecular Physiology, Loyola University Chicago, Maywood, IL, USA.,Center for Genetic Medicine, Northwestern University, Chicago, IL, USA
| | - Mayandi Sivaguru
- Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Champaign, IL, USA
| | - Gina Kuffel
- Public Health Sciences, Loyola University Chicago, Maywood, IL, USA
| | | | - Kyoung Hwan Lee
- Division of Cell Biology and Imaging, Department of Radiology, University of Massachusetts Medical School, Worcester, MA, USA
| | - Roger Craig
- Division of Cell Biology and Imaging, Department of Radiology, University of Massachusetts Medical School, Worcester, MA, USA
| | - Rajasekaran Namakkal-Soorappan
- Molecular and Cellular Pathology, Department of Pathology, School of Medicine, The University of Alabama at Birmingham, Birmingham, AL, USA
| | - Sakthivel Sadayappan
- Cell and Molecular Physiology, Loyola University Chicago, Maywood, IL, USA.,Heart, Lung and Vascular Institute, Division of Cardiovascular Health and Disease, Department of Internal Medicine, University of Cincinnati, 231 Albert Sabin Way, Cincinnati, OH, USA
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17
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Robinson DE, Lane J, Craig R, Judge A, Bailey J, Yu D, Jordan K, Peat G, Wilkie R, Silman A, Strauss VY, Prieto-Alhambra D. FRI0511 THE DESCRIPTIVE EPIDEMIOLOGY AND SECULAR TRENDS OF LOWER BACK PAIN PROCEDURES IN ROUTINE UK NHS CARE FROM 2000 TO 2016. Ann Rheum Dis 2020. [DOI: 10.1136/annrheumdis-2020-eular.3230] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Background:The lifetime prevalence of lower back pain is between 60% and 70%, with surgical treatments spared for those not responding to other options.Objectives:To investigate the age, gender and socio-economic status differences in back pain procedures in the UK between 2000, 2008 and 2016.Methods:Data was obtained from primary care electronic medical records (CPRD GOLD) linked to English hospital admissions data. Lower back procedures in patients aged 35+ were identified using OPCS-4 codes for Decompression (Dc), Fusion (F), Therapeutic injections (TI) and Denervation (Dn). Standardised incidence rates (IR) of each type of lower back procedures were calculated per 10,000 CPRD registered person years for each age group, gender, region and SES strata in 2000, 2008 and 2016. IR were also calculated for combinations of age and gender. Negative binomial regression calculated incidence rate ratios (IRR) and 95% confidence intervals.Results:The IR of lower back procedures was 21.5 [20.7, 22.3] per 10,000 person years in 2000. This doubled by 2008 (45.5 [44.5, 46.5]) and trebled by 2016 (62.5 [60.8, 64.2]). Number of events and incidence rates of each procedure type are shown in table 1 below. The incidence of Dn has increased 6-fold whilst Dc and F have doubled. Female (IR in 2016 of 73.99 [71.43, 76.61] vs 50.08 [47.90, 52.33] in men, IRR 1.50 [1.41, 1.59]) and age are associated with back procedure rates (figure 1). Large socio-economic differences were observed, with higher procedure rates seen in the most deprived areas. These differences did however narrow over time during the study period (figure 2).Table 1.Event numbers and incidence rates of different types of lower back procedure.FusionDecompressionTherapeutic InjectionDenervationEventsIR (95% CI)EventsIR (95% CI)EventsIR (95% CI)EventsIR (95% CI)20001090.86 (0.71, 1.04)4663.69 (3.36, 4.04)203516.11 (15.42, 16.82)910.72 (0.58, 0.88)20083331.77 (1.58, 1.97)11976.35 (6.00, 6.72)628333.35 (32.53, 34.18)5963.16 (2.91, 3.43)20161591.93 (1.65, 2.26)5256.39 (5.85, 6.96)386547.03 (45.56, 48.54)4875.93 (5.41, 6.48)Figure 1.Age and Gender stratified incidence rate ratios of all back procedures in 2000, 2008 and 2016Figure 2.Deprivation status incidence rate ratios by yearConclusion:The incidence of lower back procedures has more than trebled since 2000. Women are more likely to have lower back procedures than men, with patients aged 65-74 the most likely to have a procedure. Procedures in those aged 75+ have become more common over time, potentially increasing the risk of post-operative complications. Socio-economic differences in the incidence of low back procedures are probably related to the known higher prevalence of back pain in deprived areas. Whether the observed narrowing in socio-economic variation over time is explained by a reduced need or by lowered provision needs further research.Disclosure of Interests:Danielle E Robinson: None declared, Jennifer Lane: None declared, Richard Craig: None declared, Andrew Judge: None declared, James Bailey: None declared, Dahai Yu: None declared, Kelvin Jordan: None declared, George Peat: None declared, Ross Wilkie: None declared, Alan Silman: None declared, Victoria Y Strauss: None declared, Daniel Prieto-Alhambra Grant/research support from: Professor Prieto-Alhambra has received research Grants from AMGEN, UCB Biopharma and Les Laboratoires Servier, Consultant of: DPA’s department has received fees for consultancy services from UCB Biopharma, Speakers bureau: DPA’s department has received fees for speaker and advisory board membership services from Amgen
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18
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Padron R, Ma W, Duno Miranda S, Koubassova N, Lee K, Tiwari P, Pinto A, Bolaños P, Tsaturyan A, Irving TC, Craig R. Thick Filament Activation and Post-Tetanic Potentiation Mechanisms Evolved Differently in Invertebrate and Vertebrate Striated Muscle. Biophys J 2020. [DOI: 10.1016/j.bpj.2019.11.2743] [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: 11/15/2022] Open
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19
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Tiwari P, Lee K, Sato O, Ikebe M, Craig R. Flexibility of Myosin II in Solution. Biophys J 2020. [DOI: 10.1016/j.bpj.2019.11.2437] [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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20
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Woodhead JL, Craig R. The mesa trail and the interacting heads motif of myosin II. Arch Biochem Biophys 2019; 680:108228. [PMID: 31843643 DOI: 10.1016/j.abb.2019.108228] [Citation(s) in RCA: 11] [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: 10/03/2019] [Revised: 12/09/2019] [Accepted: 12/12/2019] [Indexed: 01/21/2023]
Abstract
Myosin II molecules in the thick filaments of striated muscle form a structure in which the heads interact with each other and fold back onto the tail. This structure, the "interacting heads motif" (IHM), provides a mechanistic basis for the auto-inhibition of myosin in relaxed thick filaments. Similar IHM interactions occur in single myosin molecules of smooth and nonmuscle cells in the switched-off state. In addition to the interaction between the two heads, which inhibits their activity, the IHM also contains an interaction between the motor domain of one head and the initial part (subfragment 2, S2) of the tail. This is thought to be a crucial anchoring interaction that holds the IHM in place on the thick filament. S2 appears to cross the head at a specific location within a broader region of the motor domain known as the myosin mesa. Here, we show that the positive and negative charge distribution in this part of the mesa is complementary to the charge distribution on S2. We have designated this the "mesa trail" owing to its linear path across the mesa. We studied the structural sequence alignment, the location of charged residues on the surface of myosin head atomic models, and the distribution of surface charge potential along the mesa trail in different types of myosin II and in different species. The charge distribution in both the mesa trail and the adjacent S2 is relatively conserved. This suggests a common basis for IHM formation across different myosin IIs, dependent on attraction between complementary charged patches on S2 and the myosin head. Conservation from mammals to insects suggests that the mesa trail/S2 interaction plays a key role in the inhibitory function of the IHM.
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Affiliation(s)
- John L Woodhead
- Division of Cell Biology and Imaging, Department of Radiology, University of Massachusetts Medical School, Worcester, MA, 01655, USA
| | - Roger Craig
- Division of Cell Biology and Imaging, Department of Radiology, University of Massachusetts Medical School, Worcester, MA, 01655, USA.
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21
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Ma W, Lee KH, Yang S, Irving TC, Craig R. Lattice arrangement of myosin filaments correlates with fiber type in rat skeletal muscle. J Gen Physiol 2019; 151:1404-1412. [PMID: 31699797 PMCID: PMC6888752 DOI: 10.1085/jgp.201912460] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Accepted: 10/09/2019] [Indexed: 12/22/2022] Open
Abstract
Ma et al. studied the 3-D arrangement of thick filaments in skeletal muscle by x-ray diffraction and electron microscopy and found a correlation between thick filament lattice type (simple or superlattice) and fiber type (fast/slow). This suggests that lattice organization contributes to muscle functional properties. The thick (myosin-containing) filaments of vertebrate skeletal muscle are arranged in a hexagonal lattice, interleaved with an array of thin (actin-containing) filaments with which they interact to produce contraction. X-ray diffraction and EM have shown that there are two types of thick filament lattice. In the simple lattice, all filaments have the same orientation about their long axis, while in the superlattice, nearest neighbors have rotations differing by 0° or 60°. Tetrapods (amphibians, reptiles, birds, and mammals) typically have only a superlattice, while the simple lattice is confined to fish. We have performed x-ray diffraction and electron microscopy of the soleus (SOL) and extensor digitorum longus (EDL) muscles of the rat and found that while the EDL has a superlattice as expected, the SOL has a simple lattice. The EDL and SOL of the rat are unusual in being essentially pure fast and slow muscles, respectively. The mixed fiber content of most tetrapod muscles and/or lattice disorder may explain why the simple lattice has not been apparent in these vertebrates before. This is supported by only weak simple lattice diffraction in the x-ray pattern of mouse SOL, which has a greater mix of fiber types than rat SOL. We conclude that the simple lattice might be common in tetrapods. The correlation between fiber type and filament lattice arrangement suggests that the lattice arrangement may contribute to the functional properties of a muscle.
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Affiliation(s)
- Weikang Ma
- Department of Biological Sciences, Illinois Institute of Technology, Chicago, IL
| | - Kyoung Hwan Lee
- Division of Cell Biology and Imaging, Department of Radiology, University of Massachusetts Medical School, Worcester, MA
| | - Shixin Yang
- Division of Cell Biology and Imaging, Department of Radiology, University of Massachusetts Medical School, Worcester, MA
| | - Thomas C Irving
- Department of Biological Sciences, Illinois Institute of Technology, Chicago, IL
| | - Roger Craig
- Division of Cell Biology and Imaging, Department of Radiology, University of Massachusetts Medical School, Worcester, MA
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22
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Yang S, Lee KH, Woodhead JL, Sato O, Ikebe M, Craig R. The central role of the tail in switching off 10S myosin II activity. J Gen Physiol 2019; 151:1081-1093. [PMID: 31387899 PMCID: PMC6719407 DOI: 10.1085/jgp.201912431] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Accepted: 07/08/2019] [Indexed: 01/06/2023] Open
Abstract
Three-dimensional electron microscopy reveals that myosin II molecules are kept inactive by intramolecular interactions between the heads and the tail that inhibit actin binding, ATPase activity, filament formation, and phosphorylation. This suggests how myosin can be stored in cells with minimal energy consumption. Myosin II is a motor protein with two heads and an extended tail that plays an essential role in cell motility. Its active form is a polymer (myosin filament) that pulls on actin to generate motion. Its inactive form is a monomer with a compact structure (10S sedimentation coefficient), in which the tail is folded and the two heads interact with each other, inhibiting activity. This conformation is thought to function in cells as an energy-conserving form of the molecule suitable for storage as well as transport to sites of filament assembly. The mechanism of inhibition of the compact molecule is not fully understood. We have performed a 3-D reconstruction of negatively stained 10S myosin from smooth muscle in the inhibited state using single-particle analysis. The reconstruction reveals multiple interactions between the tail and the two heads that appear to trap ATP hydrolysis products, block actin binding, hinder head phosphorylation, and prevent filament formation. Blocking these essential features of myosin function could explain the high degree of inhibition of the folded form of myosin thought to underlie its energy-conserving function in cells. The reconstruction also suggests a mechanism for unfolding when myosin is activated by phosphorylation.
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Affiliation(s)
- Shixin Yang
- Division of Cell Biology and Imaging, Department of Radiology, University of Massachusetts Medical School, Worcester, MA
| | - Kyoung Hwan Lee
- Division of Cell Biology and Imaging, Department of Radiology, University of Massachusetts Medical School, Worcester, MA
| | - John L Woodhead
- Division of Cell Biology and Imaging, Department of Radiology, University of Massachusetts Medical School, Worcester, MA
| | - Osamu Sato
- Department of Cellular and Molecular Biology, University of Texas Health Science Center at Tyler, Tyler, TX
| | - Mitsuo Ikebe
- Department of Cellular and Molecular Biology, University of Texas Health Science Center at Tyler, Tyler, TX
| | - Roger Craig
- Division of Cell Biology and Imaging, Department of Radiology, University of Massachusetts Medical School, Worcester, MA
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23
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Joyce D, Craig R, Mansoor S, Toomey S. Laparoscopic Guided Regional Analgesia (Lagra) Reduces Post-Operative Pain After Laparoscopic Cholecystectomy. Ir Med J 2019; 112:957. [PMID: 31538754] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Affiliation(s)
- D Joyce
- Department of General and Colorectal Surgery, Regional Hospital Mullingar, County Westmeath, Ireland
| | - R Craig
- Department of General and Colorectal Surgery, Regional Hospital Mullingar, County Westmeath, Ireland
| | - S Mansoor
- Department of General and Colorectal Surgery, Regional Hospital Mullingar, County Westmeath, Ireland
| | - S Toomey
- Department of General and Colorectal Surgery, Regional Hospital Mullingar, County Westmeath, Ireland
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24
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Abstract
Irving and Craig reflect on new work showing that thick filament activation involves myosin motors returning to their OFF state during diastole.
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Affiliation(s)
- Thomas C Irving
- Center for Synchrotron Radiation Research and Instrumentation and Department of Biological Sciences, Illinois Institute of Technology, Chicago, IL
| | - Roger Craig
- Division of Cell Biology and Imaging, Department of Radiology, University of Massachusetts Medical School, Worcester, MA
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25
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Joyce DP, Craig R, Dakin A, Elsheik H, Ejaz T, Mansoor S, Toomey DP. Scope and Safety of Paediatric Surgery in a Model III Hospital. Ir Med J 2019; 112:896. [PMID: 31045335] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Introduction Elective and emergency paediatric general surgery is performed in numerous hospitals but with differing exclusion and transfer thresholds. Recent national guidelines detail necessary surgical, anaesthetic and nursing resources for safe and efficient delivery of services. Methods A retrospective review of paediatric surgical admissions was performed from January 2015 to December 2016. Charts of prolonged admissions or readmissions were reviewed. Results There was a total of 2,079 surgical admissions. 575 (27.2%) were elective and 1504 (71.2%) were emergency admissions. Significantly more surgical procedures were performed in 2016 (n=546, 56% versus n=433, 44.2%). Laparoscopic appendicectomy was the most commonly performed procedure. Re-admission rates were lower in 2016 (n=9, 0.8% versus n=21, 2.2%). All complications were Clavien-Dindo Grade I or II. Discussion Paediatric general surgery can be safely and efficiently performed by staffed and resourced Model III hospitals.
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Affiliation(s)
- D P Joyce
- Department of Surgery, Regional Hospital Mullingar, Co. Westmeath
| | - R Craig
- Department of Surgery, Regional Hospital Mullingar, Co. Westmeath
| | - A Dakin
- Department of Surgery, Regional Hospital Mullingar, Co. Westmeath
| | - H Elsheik
- Department of Surgery, Regional Hospital Mullingar, Co. Westmeath
| | - T Ejaz
- Department of Surgery, Regional Hospital Mullingar, Co. Westmeath
| | - S Mansoor
- Department of Surgery, Regional Hospital Mullingar, Co. Westmeath
| | - D P Toomey
- Department of Surgery, Regional Hospital Mullingar, Co. Westmeath
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26
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Ma W, Hwan Lee K, Yang S, Irving T, Craig R. Lattice Arrangement of Myosin Filaments Correlates with Fiber Type in Rat Skeletal Muscle. Biophys J 2019. [DOI: 10.1016/j.bpj.2018.11.2191] [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: 10/27/2022] Open
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27
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Rahmanseresht S, Lee K, Robbins J, Warshaw DM, Craig R, Previs MJ. Resolving the Actin Lattice and Identifying the Relative Position of MYBP-C's N-Terminus in Cardiac Muscle using Storm Microscopy. Biophys J 2019. [DOI: 10.1016/j.bpj.2018.11.653] [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: 10/27/2022] Open
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28
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Craig R, Deeley A. Anaesthesia for pyloromyotomy. BJA Educ 2018; 18:173-177. [PMID: 33456829 DOI: 10.1016/j.bjae.2018.03.001] [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] [Accepted: 03/05/2018] [Indexed: 10/17/2022] Open
Affiliation(s)
- R Craig
- Alder Hey Children's Hospital, Liverpool, UK
| | - A Deeley
- Alder Hey Children's Hospital, Liverpool, UK
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29
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Lin BL, Li A, Mun JY, Previs MJ, Previs SB, Campbell SG, Dos Remedios CG, Tombe PDP, Craig R, Warshaw DM, Sadayappan S. Skeletal myosin binding protein-C isoforms regulate thin filament activity in a Ca 2+-dependent manner. Sci Rep 2018; 8:2604. [PMID: 29422607 PMCID: PMC5805719 DOI: 10.1038/s41598-018-21053-1] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Accepted: 01/29/2018] [Indexed: 01/17/2023] Open
Abstract
Muscle contraction, which is initiated by Ca2+, results in precise sliding of myosin-based thick and actin-based thin filament contractile proteins. The interactions between myosin and actin are finely tuned by three isoforms of myosin binding protein-C (MyBP-C): slow-skeletal, fast-skeletal, and cardiac (ssMyBP-C, fsMyBP-C and cMyBP-C, respectively), each with distinct N-terminal regulatory regions. The skeletal MyBP-C isoforms are conditionally coexpressed in cardiac muscle, but little is known about their function. Therefore, to characterize the functional differences and regulatory mechanisms among these three isoforms, we expressed recombinant N-terminal fragments and examined their effect on contractile properties in biophysical assays. Addition of the fragments to in vitro motility assays demonstrated that ssMyBP-C and cMyBP-C activate thin filament sliding at low Ca2+. Corresponding 3D electron microscopy reconstructions of native thin filaments suggest that graded shifts of tropomyosin on actin are responsible for this activation (cardiac > slow-skeletal > fast-skeletal). Conversely, at higher Ca2+, addition of fsMyBP-C and cMyBP-C fragments reduced sliding velocities in the in vitro motility assays and increased force production in cardiac muscle fibers. We conclude that due to the high frequency of Ca2+ cycling in cardiac muscle, cardiac MyBP-C may play dual roles at both low and high Ca2+. However, skeletal MyBP-C isoforms may be tuned to meet the needs of specific skeletal muscles.
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Affiliation(s)
- Brian Leei Lin
- Department of Cell and Molecular Physiology, Health Sciences Division, Loyola University Chicago, Maywood, IL, 60153, USA
| | - Amy Li
- Department of Molecular Physiology and Biophysics, University of Vermont, Burlington, VT, 05405, USA
- Bosch Institute, Discipline of Anatomy and Histology, University of Sydney, Sydney, 2006, Australia
| | - Ji Young Mun
- Department of Cell and Developmental Biology, University of Massachusetts Medical School, Worcester, MA, 01655, USA
- Department of Structure and Function of Neural Network, Korea Brain Research Institute, Dong-gu, Daegu, Korea
| | - Michael J Previs
- Department of Molecular Physiology and Biophysics, University of Vermont, Burlington, VT, 05405, USA
| | - Samantha Beck Previs
- Department of Molecular Physiology and Biophysics, University of Vermont, Burlington, VT, 05405, USA
| | - Stuart G Campbell
- Departments of Biomedical Engineering and Cellular and Molecular Physiology, Yale University, New Haven, CT, 06520, USA
| | - Cristobal G Dos Remedios
- Bosch Institute, Discipline of Anatomy and Histology, University of Sydney, Sydney, 2006, Australia
| | - Pieter de P Tombe
- Department of Cell and Molecular Physiology, Health Sciences Division, Loyola University Chicago, Maywood, IL, 60153, USA
| | - Roger Craig
- Department of Cell and Developmental Biology, University of Massachusetts Medical School, Worcester, MA, 01655, USA
| | - David M Warshaw
- Department of Molecular Physiology and Biophysics, University of Vermont, Burlington, VT, 05405, USA
| | - Sakthivel Sadayappan
- Department of Cell and Molecular Physiology, Health Sciences Division, Loyola University Chicago, Maywood, IL, 60153, USA.
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30
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Rahmanseresht S, Lee K, Robbins J, Warshaw DM, Craig R, Previs MJ. Pushing the Boundary of Storm Resolution: Seeing the Actin Lattice in Muscle. Biophys J 2018. [DOI: 10.1016/j.bpj.2017.11.117] [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: 10/18/2022] Open
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31
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Affiliation(s)
- R Craig
- School of Zoology, University of New South Wales, Kensington, N.S.W., 2033, Australia
| | - R H Crozier
- School of Zoology, University of New South Wales, Kensington, N.S.W., 2033, Australia
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32
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Yang S, Lee K, Sato O, Ikebe M, Craig R. 3D Reconstruction of the Folded, Inhibited Form of Vertebrate Smooth Muscle Myosin II by Single Particle Analysis. Biophys J 2017. [DOI: 10.1016/j.bpj.2016.11.1443] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [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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33
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Li A, Nelson S, Lee K, Previs S, Brack K, Previs M, Govindan S, Sadayappan S, Craig R, Warshaw D. Skeletal Myosin-Binding Protein C Modulates Actomyosin Contractility in an Isoform-Dependent Manner. Biophys J 2017. [DOI: 10.1016/j.bpj.2016.11.659] [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: 10/20/2022] Open
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34
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Kirk JA, Chakir K, Lee KH, Karst E, Holewinski RJ, Pironti G, Tunin RS, Pozios I, Abraham TP, de Tombe P, Rockman HA, Van Eyk JE, Craig R, Farazi TG, Kass DA. Pacemaker-induced transient asynchrony suppresses heart failure progression. Sci Transl Med 2017; 7:319ra207. [PMID: 26702095 DOI: 10.1126/scitranslmed.aad2899] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Uncoordinated contraction from electromechanical delay worsens heart failure pathophysiology and prognosis, but restoring coordination with biventricular pacing, known as cardiac resynchronization therapy (CRT), improves both. However, not every patient qualifies for CRT. We show that heart failure with synchronous contraction is improved by inducing dyssynchrony for 6 hours daily by right ventricular pacing using an intracardiac pacing device, in a process we call pacemaker-induced transient asynchrony (PITA). In dogs with heart failure induced by 6 weeks of atrial tachypacing, PITA (starting on week 3) suppressed progressive cardiac dilation as well as chamber and myocyte dysfunction. PITA enhanced β-adrenergic responsiveness in vivo and normalized it in myocytes. Myofilament calcium response declined in dogs with synchronous heart failure, which was accompanied by sarcomere disarray and generation of myofibers with severely reduced function, and these changes were absent in PITA-treated hearts. The benefits of PITA were not replicated when the same number of right ventricular paced beats was randomly distributed throughout the day, indicating that continuity of dyssynchrony exposure is necessary to trigger the beneficial biological response upon resynchronization. These results suggest that PITA could bring the benefits of CRT to the many heart failure patients with synchronous contraction who are not CRT candidates.
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Affiliation(s)
- Jonathan A Kirk
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Khalid Chakir
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Kyoung Hwan Lee
- Department of Cell and Developmental Biology, University of Massachusetts Medical School, Worcester, MA 01655, USA
| | | | - Ronald J Holewinski
- Advanced Clinical Biosystems Research Institute, Heart Institute and Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA
| | - Gianluigi Pironti
- Department of Medicine, Duke University School of Medicine, Durham, NC 27710, USA
| | - Richard S Tunin
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Iraklis Pozios
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Theodore P Abraham
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Pieter de Tombe
- Department of Cell and Molecular Physiology, Loyola University Stritch School of Medicine, Maywood, IL 60153, USA
| | - Howard A Rockman
- Department of Medicine, Duke University School of Medicine, Durham, NC 27710, USA
| | - Jennifer E Van Eyk
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA. Advanced Clinical Biosystems Research Institute, Heart Institute and Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA
| | - Roger Craig
- Department of Cell and Developmental Biology, University of Massachusetts Medical School, Worcester, MA 01655, USA
| | | | - David A Kass
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
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35
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Lynch TL, Kuster DW, Sivaguru M, Previs MJ, Lee K, Govindan S, Craig R, Warshaw DM, Sadayappan S. Abstract 389: Amino Terminal Region of Cardiac Myosin Binding Protein-C is Necessary for Cardiac Function. Circ Res 2016. [DOI: 10.1161/res.119.suppl_1.389] [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
Rationale:
Cardiac myosin binding protein-C (cMyBP-C) is a thick filament-associated protein that has been suggested to regulate cardiac contraction via its amino terminal (N’) region. However, the necessity of the N’-C0-C1f region (domains C0 through C1 and the first 17 residues of the M-domain) of cMyBP-C in regulating cardiac function
in vivo
has not been elucidated.
Hypothesis:
The N’-C0-C1f region of cMyBP-C is critical for normal cardiac function
in vivo
.
Methods and Results:
Transgenic mice with 80±4% expression of a truncated cMyBP-C missing the N’-C0-C1f region (cMyBP-C
110kDa
) were generated and characterized at 3-months of age. cMyBP-C
110kDa
animals exhibited cardiac hypertrophy as suggested by an increased heart weight to body weight ratio (5.0±0.1 mg/g NTG vs. 6.9±0.1 mg/g cMyBP-C
110kDa
, p<0.0001) and an elevation in pathological hypertrophy markers determined by real-time PCR. Histopathological analysis showed increased cardiac fibrosis in cMyBP-C
110kDa
hearts compared to hearts from non-transgenic (NTG) littermates. Intriguingly, increased phosphorylation of cMyBP-C at Ser-282 and Ser-302, sites important for cMyBP-C’s regulation of actomyosin interactions, was observed in cMyBP-C
110kDa
hearts compared to controls. Electron microscopy revealed normal sarcomere structure in cMyBP-C
110kDa
hearts but with apparently weaker cMyBP-C stripes. Furthermore, the ability of cMyBP-C to slow actin-filament sliding within the C-zone of native thick filaments isolated from NTG hearts was lost on thick filaments from cMyBP-C
110kDa
hearts. Short-axis M-mode echocardiography indicated a significant elevation in left ventricular internal diameter and a significant reduction in fractional shortening (31±5% NTG vs. 16±3% cMyBP-C
110kDa
, p=0.0003) in cMyBP-C
110kDa
hearts compared to controls. Finally, global longitudinal strain analysis revealed abnormal wall motion in cMyBP-C
110kDa
hearts. Based upon these data, we propose that the N’-region of cMyBP-C is a critical regulator of actomyosin interactions and controls aberrant contraction kinetics within the cardiac sarcomere.
Conclusion:
The N’-C0-C1f region of cMyBP-C regulates cardiac contractility and is necessary for maintaining normal cardiac function
in vivo
.
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Affiliation(s)
| | | | | | | | | | | | - Roger Craig
- Univ of Massachusetts Med Sch, Worcester, MA
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36
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Affiliation(s)
- John L Woodhead
- Department of Cell and Developmental Biology, University of Massachusetts Medical School, Worcester, Massachusetts
| | - Roger Craig
- Department of Cell and Developmental Biology, University of Massachusetts Medical School, Worcester, Massachusetts.
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37
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Sivaguru M, Lynch TL, Kuster DW, Govindan S, Sadayappan S, Previs MJ, Warshaw DM, Lee K, Craig R. ID: 136: N-TERMINAL REGION OF CARDIAC MYOSIN BINDING PROTEIN-C IS NECESSARY FOR CARDIAC FUNCTION. J Investig Med 2016. [DOI: 10.1136/jim-2016-000120.2] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
RationaleCardiac myosin binding protein-C (cMyBP-C) is a trans-filament protein that has been shown to regulate cardiac function via its amino terminal (N′) region. In vitro studies have suggested the importance of the first 271 N′-residues of cMyBP-C (C0-C1f region) in slowing actin filament sliding over myosin to regulate cross-bridge cycling kinetics within the cardiac sarcomere. However, the role and necessity of the C0-C1f region of cMyBP-C in regulating contractile and cardiac function in vivo have not been elucidated.HypothesisThe N′-C0-C1f region of cMyBP-C is critical for proper cardiac function in vivo.Methods and ResultsTransgenic mice with approximately 95% expression of a mutant truncated cMyBP-C missing the N′-C0-C1f region (cMyBP-C110 kDa), compared to endogenous cMyBP-C, were generated and characterized at 3-months of age. cMyBP-C110 kDa hearts had significantly elevated heart weight/body weight ratio, fibrosis, nuclear area and collagen content compared to hearts from non-transgenic (NTG) littermates. Electron microscopic analysis revealed normal sarcomere structure in cMyBP-C110 kDa hearts but with apparently weaker cMyBP-C stripes. Furthermore, the ability of cMyBP-C to slow actin-filament sliding within the C-zone of native thick filaments isolated from NTG hearts was lost on thick filaments from cMyBP-C110 kDa hearts. Short axis M-mode echocardiography revealed a significant increase in left ventricular (LV) internal diameter during diastole in cMyBP-C110 kDa hearts. Importantly, cMyBP-C110 kDa hearts displayed a significant reduction in fractional shortening compared to hearts from NTG mice. We further observed a decrease in the thickness of the LV interventricular septum and free wall during systole in cMyBP-C110 kDa hearts. Strain analysis using images acquired from ECG-Gated Kilohertz Visualization identified a significant deficit in global longitudinal strain in cMyBP-C110 kDa hearts compared to NTG hearts. Consistent with cardiac hypertrophy, we observed a significant increase in the expression of the hypertrophic genes MYH7 and NPPA by real-time PCR analysis. As expected, the expression levels of the MYBPC3 gene were significantly elevated in cMyBP-C110 kDa hearts compared to NTG hearts. Surprisingly, our Western blot analyses revealed no significant difference in total cMyBP-C levels between NTG and cMyBP-C110 kDa heart homogenates. However, intriguingly, we observed a significant elevation in cMyBP-C phosphorylation at Ser-273, Ser-282, and Ser-302, sites important for cMyBP-C's regulation of actomyosin interaction, in cMyBP-C110 kDa heart homogenates compared to those from NTG mice.ConclusionThe N′-C0-C1f region of cMyBP-C is essential for maintaining normal cardiac morphology and function in vivo and loss of this region promotes contractile dysfunction both at the molecular and tissue level.
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38
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Lee K, Yang S, Liu X, Korn ED, Sarsoza F, Bernstein SI, Pollard L, Lord MJ, Trybus KM, Craig R. Myosin II Head Interaction in Primitive Species. Biophys J 2016. [DOI: 10.1016/j.bpj.2015.11.3299] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [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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39
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Previs MJ, Young Mun J, Michalek AJ, Beck Previs S, Gulick J, Robbins J, Warshaw DM, Craig R. Phosphorylation and Calcium Antagonistically Tune Myosin-Binding Protein C's Molecular Structure and Function. Biophys J 2016. [DOI: 10.1016/j.bpj.2015.11.1583] [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: 10/22/2022] Open
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40
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Mun JY, Kensler RW, Harris SP, Craig R. The cMyBP-C HCM variant L348P enhances thin filament activation through an increased shift in tropomyosin position. J Mol Cell Cardiol 2015; 91:141-7. [PMID: 26718724 DOI: 10.1016/j.yjmcc.2015.12.014] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [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] [Received: 08/21/2015] [Revised: 12/08/2015] [Accepted: 12/18/2015] [Indexed: 10/22/2022]
Abstract
Mutations in cardiac myosin binding protein C (cMyBP-C), a thick filament protein that modulates contraction of the heart, are a leading cause of hypertrophic cardiomyopathy (HCM). Electron microscopy and 3D reconstruction of thin filaments decorated with cMyBP-C N-terminal fragments suggest that one mechanism of this modulation involves the interaction of cMyBP-C's N-terminal domains with thin filaments to enhance their Ca(2+)-sensitivity by displacement of tropomyosin from its blocked (low Ca(2+)) to its closed (high Ca(2+)) position. The extent of this tropomyosin shift is reduced when cMyBP-C N-terminal domains are phosphorylated. In the current study, we have examined L348P, a sequence variant of cMyBP-C first identified in a screen of patients with HCM. In L348P, leucine 348 is replaced by proline in cMyBP-C's regulatory M-domain, resulting in an increase in cMyBP-C's ability to enhance thin filament Ca(2+)-sensitization. Our goal here was to determine the structural basis for this enhancement by carrying out 3D reconstruction of thin filaments decorated with L348P-mutant cMyBP-C. When thin filaments were decorated with wild type N-terminal domains at low Ca(2+), tropomyosin moved from the blocked to the closed position, as found previously. In contrast, the L348P mutant caused a significantly larger tropomyosin shift, to approximately the open position, consistent with its enhancement of Ca(2+)-sensitization. Phosphorylated wild type fragments showed a smaller shift than unphosphorylated fragments, whereas the shift induced by the L348P mutant was not affected by phosphorylation. We conclude that the L348P mutation causes a gain of function by enhancing tropomyosin displacement on the thin filament in a phosphorylation-independent way.
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Affiliation(s)
- Ji Young Mun
- Department of Cell and Developmental Biology, University of Massachusetts Medical School, Worcester, MA 01655, USA
| | - Robert W Kensler
- Department of Anatomy and Neurobiology, University of Puerto Rico School of Medicine, San Juan, PR 00936, USA
| | - Samantha P Harris
- Department of Cellular and Molecular Medicine, University of Arizona College of Medicine, Tucson, AZ 85724, USA
| | - Roger Craig
- Department of Cell and Developmental Biology, University of Massachusetts Medical School, Worcester, MA 01655, USA.
| |
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41
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Yang S, Woodhead JL, Zhao FQ, Sulbarán G, Craig R. An approach to improve the resolution of helical filaments with a large axial rise and flexible subunits. J Struct Biol 2015; 193:45-54. [PMID: 26592473 DOI: 10.1016/j.jsb.2015.11.007] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [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: 06/30/2015] [Revised: 11/12/2015] [Accepted: 11/20/2015] [Indexed: 11/18/2022]
Abstract
Single particle analysis is widely used for three-dimensional reconstruction of helical filaments. Near-atomic resolution has been obtained for several well-ordered filaments. However, it is still a challenge to achieve high resolution for filaments with flexible subunits and a large axial rise per subunit relative to pixel size. Here, we describe an approach that improves the resolution in such cases. In filaments with a large axial rise, many segments must be shifted a long distance along the filament axis to match with a reference projection, potentially causing loss of alignment accuracy and hence resolution. In our study of myosin filaments, we overcame this problem by pre-determining the axial positions of myosin head crowns within segments to decrease the alignment error. In addition, homogeneous, well-ordered segments were selected from the raw data set by checking the assigned azimuthal rotation angle of segments in each filament against those expected for perfect helical symmetry. These procedures improved the resolution of the filament reconstruction from 30 Å to 13 Å. This approach could be useful in other helical filaments with a large axial rise and/or flexible subunits.
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Affiliation(s)
- Shixin Yang
- Department of Cell and Developmental Biology, University of Massachusetts Medical School, Worcester, MA 01655, USA
| | - John L Woodhead
- Department of Cell and Developmental Biology, University of Massachusetts Medical School, Worcester, MA 01655, USA
| | - Fa-Qing Zhao
- Department of Cell and Developmental Biology, University of Massachusetts Medical School, Worcester, MA 01655, USA
| | - Guidenn Sulbarán
- Department of Cell and Developmental Biology, University of Massachusetts Medical School, Worcester, MA 01655, USA
| | - Roger Craig
- Department of Cell and Developmental Biology, University of Massachusetts Medical School, Worcester, MA 01655, USA.
| |
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42
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Woodhall SC, Murphy G, Craig R, Mindell JS, Soldan K, Johnson AM, Nardone A. P10.19 Can hsv-2 seropositivity be used as a biological marker of sexual behaviour? findings from a seroprevalence survey in england. Br J Vener Dis 2015. [DOI: 10.1136/sextrans-2015-052270.447] [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: 11/04/2022]
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43
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Woodhall SC, Wills G, Horner P, Craig R, Mindell JS, Murphy G, McClure M, Soldan K, Nardone A, Johnson AM. P08.12 Insights into chlamydia trachomatiscumulative incidence in the context of widespread opportunistic chlamydia screening in england: seroprevalence study using sera from a nationally-representative household survey. Br J Vener Dis 2015. [DOI: 10.1136/sextrans-2015-052270.358] [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: 11/04/2022]
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44
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Lynch TL, Kuster DW, Barefield D, Sivaguru M, Previs MJ, Lee K, Govindan S, Craig R, Warshaw DM, Sadayappan S. Abstract 376: Amino Terminal C0-C1f Region of Cardiac Myosin Binding Protein-C is Essential for Normal Cardiac Function. Circ Res 2015. [DOI: 10.1161/res.117.suppl_1.376] [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
Rationale:
Cardiac myosin binding protein-C (cMyBP-C) is a trans-filament protein that has been shown to regulate cardiac function via its amino terminal (N’) regions. However, it is unknown whether the first 271 residues (C0-C1f region) are necessary to regulate contractile function in vivo.
Hypothesis:
The N’-region of cMyBP-C is critical for proper cardiac function in vivo.
Methods and Results:
Transgenic mice with approximately 80% expression of mutant truncated cMyBP-C missing C0-C1f (cMyBP-C
110kDa
), compared to endogenous cMyBP-C, were generated and characterized at 3-months of age. cMyBP-C
110kDa
hearts had significantly elevated heart weight/body weight ratio, fibrosis, nuclear area and collagen content compared to hearts from non-transgenic (NTG) littermates. Electron microscopic analysis revealed normal sarcomere structure in cMyBP-C
110kDa
hearts but with apparently weaker cMyBP-C stripes. Furthermore, the ability of cMyBP-C to slow actin-filament sliding within the C-zone of native thick filaments isolated from NTG hearts was lost on thick filaments from cMyBP-C
110kDa
hearts. Short axis M-mode echocardiography revealed a significant increase in left ventricular (LV) internal diameter during diastole in cMyBP-C
110kDa
hearts. Importantly, cMyBP-C
110kDa
hearts displayed a significant reduction in fractional shortening compared to hearts from NTG littermates. We further observed a decrease in the thickness of the LV interventricular septum and free wall during systole in cMyBP-C
110kDa
hearts. Strain analysis using images acquired from ECG-Gated Kilohertz Visualization identified a significant deficit in global longitudinal strain in cMyBP-C
110kDa
hearts compared to NTG hearts.
Conclusion:
The N’-region of cMyBP-C is indispensable for maintaining normal cardiac morphology and function and loss of this region promotes contractile dysfunction both at the molecular and tissue levels.
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Affiliation(s)
| | | | | | | | | | | | | | - Roger Craig
- Univ of Massachusetts Med Sch, Worcester, MA
| | | | | |
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45
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Kirk JA, Chakir K, Lee K, Pironti G, Ranek MJ, Tunin RS, de Tombe P, Shenoy SK, Rockman HA, Craig R, Kass DA. Abstract 358: Pacemaker Induced Transient Asynchrony (PITA) Restores Contractile Reserve in Synchronous Heart Failure. Circ Res 2015. [DOI: 10.1161/res.117.suppl_1.358] [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
Heart failure (HF) with dyssynchrony treated with biventricular pacing (CRT) displays enhanced global and cellular function even compared to always synchronous HF. This suggests while HF is worsened by sustained dyssynchrony, it may paradoxically be improved by brief periods of Pacemaker Induced Transient Asynchrony (PITA). We tested this hypothesis in dogs tachypaced for 6 wks to induce HF. The HF group received atrial pacing and was compared to PITA (atrial pacing during day; right ventricular pacing, producing dyssynchrony, from 0000-0600). PITA blunted dilation (end diastolic and end systolic volumes reduced by 11 and 19%, respectively), reduced end-diastolic pressures from 22 to 13 mmHg, and improved the contractile response to dobutamine by 29%. Myocyte sarcomere shortening and calcium transient amplitude were depressed in HF and little improved by β adrenergic (βA) stimulation. PITA improved baseline function slightly, but virtually restored βA stimulated reserve. Membrane βA receptor density increased with PITA by 36% as well. Another contributor to the change in functional reserve was found in myofilament maximal calcium activated force (Fmax) normalized to cell cross sectional area (CSA). This declined ~40% in HF vs. Control, but was fully restored by PITA. However, as CSA was greater in HF and normalized by PITA, raw Fmax was similar despite hypertrophy in HF, suggesting HF myocytes had dysfunctional myofilaments, which PITA prevented. Electron microscopy confirmed normal myofilament structure in Control and PITA, whereas 40% of HF sarcomeres displayed deteriorated z-disks and loss of normal registration of the thick and thin filaments. In HF, 39% of HF isolated myofibrils produced virtually zero maximal force, whereas Control and PITA fibers functioned normally. Thus, there are two populations of myofibrils within HF hypertrophied cells, with ~40% structurally and functionally disrupted. PITA reverses this to restore force-calcium activation and with improved βA receptor signaling, restores functional reserve, suppressing chronic maladaptive remodeling. This surprising finding indicates PITA can ameliorate HF pathobiology and improve reserve function. Further studies are needed to test if such benefits translate to humans.
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Yao M, McClements D, Zhao F, Craig R, Xiao H. Controlling the gastrointestinal fate of nutraceutical‐enriched lipid nanoparticles: From mixed micelles to chylomicrons. FASEB J 2015. [DOI: 10.1096/fasebj.29.1_supplement.249.6] [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)
- Mingfei Yao
- University of Massachusetts AmherstDepartment of Food ScienceAmherstMassachusettsUnited States
| | - David McClements
- University of Massachusetts AmherstDepartment of Food ScienceAmherstMassachusettsUnited States
| | - Faqing Zhao
- University of Massachusetts Medical School Cell and Developmental BiologyWorcesterMassachusettsUnited States
| | - Roger Craig
- University of Massachusetts Medical School Cell and Developmental BiologyWorcesterMassachusettsUnited States
| | - Hang Xiao
- University of Massachusetts AmherstDepartment of Food ScienceAmherstMassachusettsUnited States
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Li A, Beck Previs S, Previs M, Lin B, dos Remedios C, Craig R, Sadayappan S, Warshaw D. Skeletal Myosin Binding Protein-C Isoforms Modulate Actomyosin Contractility and are Regulated by Phosphorylation. Biophys J 2015. [DOI: 10.1016/j.bpj.2014.11.2304] [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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Kensler RW, Craig R, Moss RL. Crossbridge Arrangement in Cardiac Thick Filaments Isolated from cMyBP-C Phosphomimetic Mice. Biophys J 2015. [DOI: 10.1016/j.bpj.2014.11.739] [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: 10/24/2022] Open
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Previs MJ, Prosser BL, Mun JY, Previs SB, Gulick J, Lee K, Robbins J, Craig R, Lederer WJ, Warshaw DM. Myosin-binding protein C corrects an intrinsic inhomogeneity in cardiac excitation-contraction coupling. Sci Adv 2015; 1:e1400205. [PMID: 25839057 PMCID: PMC4380226 DOI: 10.1126/sciadv.1400205] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2014] [Accepted: 01/04/2015] [Indexed: 05/30/2023]
Abstract
The beating heart exhibits remarkable contractile fidelity over a lifetime, which reflects the tight coupling of electrical, chemical, and mechanical elements within the sarcomere, the elementary contractile unit. On a beat-to-beat basis, calcium is released from the ends of the sarcomere and must diffuse toward the sarcomere center to fully activate the myosin- and actin-based contractile proteins. The resultant spatial and temporal gradient in free calcium across the sarcomere should lead to nonuniform and inefficient activation of contraction. We show that myosin-binding protein C (MyBP-C), through its positioning on the myosin thick filaments, corrects this nonuniformity in calcium activation by exquisitely sensitizing the contractile apparatus to calcium in a manner that precisely counterbalances the calcium gradient. Thus, the presence and correct localization of MyBP-C within the sarcomere is critically important for normal cardiac function, and any disturbance of MyBP-C localization or function will contribute to the consequent cardiac pathologies.
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Affiliation(s)
- Michael J. Previs
- Department of Molecular Physiology and Biophysics, Cardiovascular Research Institute of Vermont, The University of Vermont, Burlington, VT 05405, USA
| | - Benjamin L. Prosser
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Ji Young Mun
- Department of Cell and Developmental Biology, University of Massachusetts Medical School, Worcester, MA 01655, USA
- Department of Biomedical Laboratory Science, College of Health Sciences, Eulji University, Seongnam-Si 461-701, Gyeonggi-Do, Republic of Korea
| | - Samantha Beck Previs
- Department of Molecular Physiology and Biophysics, Cardiovascular Research Institute of Vermont, The University of Vermont, Burlington, VT 05405, USA
| | - James Gulick
- Department of Pediatrics and the Heart Institute, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH 45229, USA
| | - Kyounghwan Lee
- Department of Cell and Developmental Biology, University of Massachusetts Medical School, Worcester, MA 01655, USA
| | - Jeffrey Robbins
- Department of Pediatrics and the Heart Institute, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH 45229, USA
| | - Roger Craig
- Department of Cell and Developmental Biology, University of Massachusetts Medical School, Worcester, MA 01655, USA
| | - W. J. Lederer
- Department of Physiology, Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - David M. Warshaw
- Department of Molecular Physiology and Biophysics, Cardiovascular Research Institute of Vermont, The University of Vermont, Burlington, VT 05405, USA
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Mun JY, Kensler RW, Harris SP, Craig R. The HCM Mutation L348P in cMyBP-C Enhances Thin Filament Activation through Tropomyosin Shift. Biophys J 2015. [DOI: 10.1016/j.bpj.2014.11.738] [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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