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Vahle B, Heilmann L, Schauer A, Augstein A, Jarabo MEP, Barthel P, Mangner N, Labeit S, Bowen TS, Linke A, Adams V. Modulation of Titin and Contraction-Regulating Proteins in a Rat Model of Heart Failure with Preserved Ejection Fraction: Limb vs. Diaphragmatic Muscle. Int J Mol Sci 2024; 25:6618. [PMID: 38928324 PMCID: PMC11203682 DOI: 10.3390/ijms25126618] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2024] [Revised: 06/12/2024] [Accepted: 06/14/2024] [Indexed: 06/28/2024] Open
Abstract
Heart failure with preserved ejection fraction (HFpEF) is characterized by biomechanically dysfunctional cardiomyocytes. Underlying cellular changes include perturbed myocardial titin expression and titin hypophosphorylation leading to titin filament stiffening. Beside these well-studied alterations at the cardiomyocyte level, exercise intolerance is another hallmark of HFpEF caused by molecular alterations in skeletal muscle (SKM). Currently, there is a lack of data regarding titin modulation in the SKM of HFpEF. Therefore, the aim of the present study was to analyze molecular alterations in limb SKM (tibialis anterior (TA)) and in the diaphragm (Dia), as a more central SKM, with a focus on titin, titin phosphorylation, and contraction-regulating proteins. This study was performed with muscle tissue, obtained from 32-week old female ZSF-1 rats, an established a HFpEF rat model. Our results showed a hyperphosphorylation of titin in limb SKM, based on enhanced phosphorylation at the PEVK region, which is known to lead to titin filament stiffening. This hyperphosphorylation could be reversed by high-intensity interval training (HIIT). Additionally, a negative correlation occurring between the phosphorylation state of titin and the muscle force in the limb SKM was evident. For the Dia, no alterations in the phosphorylation state of titin could be detected. Supported by data of previous studies, this suggests an exercise effect of the Dia in HFpEF. Regarding the expression of contraction regulating proteins, significant differences between Dia and limb SKM could be detected, supporting muscle atrophy and dysfunction in limb SKM, but not in the Dia. Altogether, these data suggest a correlation between titin stiffening and the appearance of exercise intolerance in HFpEF, as well as a differential regulation between different SKM groups.
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Affiliation(s)
- Beatrice Vahle
- Heart Center Dresden, Laboratory of Molecular and Experimental Cardiology, TU Dresden, 01307 Dresden, Germany; (B.V.); (L.H.); (A.S.); (A.A.); (M.-E.P.J.); (P.B.); (N.M.); (A.L.)
| | - Leonard Heilmann
- Heart Center Dresden, Laboratory of Molecular and Experimental Cardiology, TU Dresden, 01307 Dresden, Germany; (B.V.); (L.H.); (A.S.); (A.A.); (M.-E.P.J.); (P.B.); (N.M.); (A.L.)
| | - Antje Schauer
- Heart Center Dresden, Laboratory of Molecular and Experimental Cardiology, TU Dresden, 01307 Dresden, Germany; (B.V.); (L.H.); (A.S.); (A.A.); (M.-E.P.J.); (P.B.); (N.M.); (A.L.)
| | - Antje Augstein
- Heart Center Dresden, Laboratory of Molecular and Experimental Cardiology, TU Dresden, 01307 Dresden, Germany; (B.V.); (L.H.); (A.S.); (A.A.); (M.-E.P.J.); (P.B.); (N.M.); (A.L.)
| | - Maria-Elisa Prieto Jarabo
- Heart Center Dresden, Laboratory of Molecular and Experimental Cardiology, TU Dresden, 01307 Dresden, Germany; (B.V.); (L.H.); (A.S.); (A.A.); (M.-E.P.J.); (P.B.); (N.M.); (A.L.)
| | - Peggy Barthel
- Heart Center Dresden, Laboratory of Molecular and Experimental Cardiology, TU Dresden, 01307 Dresden, Germany; (B.V.); (L.H.); (A.S.); (A.A.); (M.-E.P.J.); (P.B.); (N.M.); (A.L.)
| | - Norman Mangner
- Heart Center Dresden, Laboratory of Molecular and Experimental Cardiology, TU Dresden, 01307 Dresden, Germany; (B.V.); (L.H.); (A.S.); (A.A.); (M.-E.P.J.); (P.B.); (N.M.); (A.L.)
| | - Siegfried Labeit
- DZHK Partner Site Mannheim-Heidelberg, Medical Faculty Mannheim, University of Heidelberg, 68169 Mannheim, Germany;
- Myomedix GmbH, 69151 Neckargemünd, Germany
| | - T. Scott Bowen
- School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK;
| | - Axel Linke
- Heart Center Dresden, Laboratory of Molecular and Experimental Cardiology, TU Dresden, 01307 Dresden, Germany; (B.V.); (L.H.); (A.S.); (A.A.); (M.-E.P.J.); (P.B.); (N.M.); (A.L.)
| | - Volker Adams
- Heart Center Dresden, Laboratory of Molecular and Experimental Cardiology, TU Dresden, 01307 Dresden, Germany; (B.V.); (L.H.); (A.S.); (A.A.); (M.-E.P.J.); (P.B.); (N.M.); (A.L.)
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Li C, Warren DT, Zhou C, De Silva S, Wilson DGS, Garcia-Maya M, Wheeler MA, Meinke P, Sawyer G, Ehler E, Wehnert M, Rao L, Zhang Q, Shanahan CM. Nesprin-2 is a novel scaffold protein for telethonin and FHL-2 in the cardiomyocyte sarcomere. J Biol Chem 2024; 300:107254. [PMID: 38569934 PMCID: PMC11078644 DOI: 10.1016/j.jbc.2024.107254] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Revised: 03/11/2024] [Accepted: 03/19/2024] [Indexed: 04/05/2024] Open
Abstract
Nesprins comprise a family of multi-isomeric scaffolding proteins, forming the linker of nucleoskeleton-and-cytoskeleton complex with lamin A/C, emerin and SUN1/2 at the nuclear envelope. Mutations in nesprin-1/-2 are associated with Emery-Dreifuss muscular dystrophy (EDMD) with conduction defects and dilated cardiomyopathy (DCM). We have previously observed sarcomeric staining of nesprin-1/-2 in cardiac and skeletal muscle, but nesprin function in this compartment remains unknown. In this study, we show that specific nesprin-2 isoforms are highly expressed in cardiac muscle and localize to the Z-disc and I band of the sarcomere. Expression of GFP-tagged nesprin-2 giant spectrin repeats 52 to 53, localized to the sarcomere of neonatal rat cardiomyocytes. Yeast two-hybrid screening of a cardiac muscle cDNA library identified telethonin and four-and-half LIM domain (FHL)-2 as potential nesprin-2 binding partners. GST pull-down and immunoprecipitation confirmed the individual interactions between nesprin-2/telethonin and nesprin-2/FHL-2, and showed that nesprin-2 and telethonin binding was dependent on telethonin phosphorylation status. Importantly, the interactions between these binding partners were impaired by mutations in nesprin-2, telethonin, and FHL-2 identified in EDMD with DCM and hypertrophic cardiomyopathy patients. These data suggest that nesprin-2 is a novel sarcomeric scaffold protein that may potentially participate in the maintenance and/or regulation of sarcomeric organization and function.
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Affiliation(s)
- Chen Li
- King's College London British Heart Foundation Centre of Research Excellence, School of Cardiovascular and Metabolic Medicine & Sciences, London, UK; Department of Cardiology, West China Hospital of Sichuan University, Chengdu, China
| | - Derek T Warren
- King's College London British Heart Foundation Centre of Research Excellence, School of Cardiovascular and Metabolic Medicine & Sciences, London, UK; School of Pharmacy, University of East Anglia, Norwich, UK
| | - Can Zhou
- King's College London British Heart Foundation Centre of Research Excellence, School of Cardiovascular and Metabolic Medicine & Sciences, London, UK
| | - Shanelle De Silva
- King's College London British Heart Foundation Centre of Research Excellence, School of Cardiovascular and Metabolic Medicine & Sciences, London, UK
| | - Darren G S Wilson
- King's College London British Heart Foundation Centre of Research Excellence, School of Cardiovascular and Metabolic Medicine & Sciences, London, UK
| | - Mitla Garcia-Maya
- Randall Centre for Cell and Molecular Biophysics, School of Basic and Medical Biosciences, King's College London, London, UK
| | - Matthew A Wheeler
- Department of Cardiac Development and Remodeling, Max-Planck-Institute for Heart and Lung Research, Bad Nauheim, Germany
| | - Peter Meinke
- Friedrich-Baur-Institute at the Department of Neurology, LMU University Hospital, Munich, Germany
| | - Greta Sawyer
- King's College London British Heart Foundation Centre of Research Excellence, School of Cardiovascular and Metabolic Medicine & Sciences, London, UK
| | - Elisabeth Ehler
- King's College London British Heart Foundation Centre of Research Excellence, School of Cardiovascular and Metabolic Medicine & Sciences, London, UK; Randall Centre for Cell and Molecular Biophysics, School of Basic and Medical Biosciences, King's College London, London, UK
| | - Manfred Wehnert
- Institute of Human Genetics, University of Greifswald, Greifswald, Germany
| | - Li Rao
- Department of Cardiology, West China Hospital of Sichuan University, Chengdu, China
| | - Qiuping Zhang
- King's College London British Heart Foundation Centre of Research Excellence, School of Cardiovascular and Metabolic Medicine & Sciences, London, UK.
| | - Catherine M Shanahan
- King's College London British Heart Foundation Centre of Research Excellence, School of Cardiovascular and Metabolic Medicine & Sciences, London, UK.
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Grogan A, Huang W, Brong A, Kane MA, Kontrogianni-Konstantopoulos A. Alterations in cytoskeletal and Ca 2+ cycling regulators in atria lacking the obscurin Ig58/59 module. Front Cardiovasc Med 2023; 10:1085840. [PMID: 37304957 PMCID: PMC10251194 DOI: 10.3389/fcvm.2023.1085840] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Accepted: 01/26/2023] [Indexed: 06/13/2023] Open
Abstract
Introduction Obscurin (720-870 kDa) is a giant cytoskeletal and signaling protein that possesses both structural and regulatory functions in striated muscles. Immunoglobulin domains 58/59 (Ig58/59) of obscurin bind to a diverse set of proteins that are essential for the proper structure and function of the heart, including giant titin, novex-3, and phospholamban (PLN). Importantly, the pathophysiological significance of the Ig58/59 module has been further underscored by the discovery of several mutations within Ig58/59 that are linked to various forms of myopathy in humans. We previously generated a constitutive deletion mouse model, Obscn-ΔIg58/59, that expresses obscurin lacking Ig58/59, and characterized the effects of this deletion on cardiac morphology and function through aging. Our findings demonstrated that Obscn-ΔIg58/59 male animals develop severe arrhythmia, primarily manifesting as episodes of junctional escape and spontaneous loss of regular p-waves, reminiscent of human atrial fibrillation, accompanied by significant atrial enlargement that progresses in severity with aging. Methods and Results To comprehensively characterize the molecular alterations responsible for these pathologies, we performed proteomic and phospho-proteomic analyses in aging Obscn-ΔIg58/59 atria. Our studies revealed extensive and novel alterations in the expression and phosphorylation profile of major cytoskeletal proteins, Ca2+ regulators, and Z-disk associated protein complexes in the Obscn-ΔIg58/59 atria through aging. Discussion These studies implicate obscurin, particularly the Ig58/59 module, as an essential regulator of the Z-disk associated cytoskeleton and Ca2+ cycling in the atria and provide new molecular insights into the development of atrial fibrillation and remodeling.
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Affiliation(s)
- Alyssa Grogan
- Department of Biochemistry and Molecular Biology, University of Maryland, Baltimore, MD, United States
| | - Weiliang Huang
- Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Baltimore, MD, United States
| | - Annie Brong
- Department of Biochemistry and Molecular Biology, University of Maryland, Baltimore, MD, United States
| | - Maureen A. Kane
- Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Baltimore, MD, United States
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Multi-Omics Profiling of Hypertrophic Cardiomyopathy Reveals Altered Mechanisms in Mitochondrial Dynamics and Excitation-Contraction Coupling. Int J Mol Sci 2023; 24:ijms24054724. [PMID: 36902152 PMCID: PMC10002553 DOI: 10.3390/ijms24054724] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2023] [Revised: 02/16/2023] [Accepted: 02/20/2023] [Indexed: 03/06/2023] Open
Abstract
Hypertrophic cardiomyopathy is one of the most common inherited cardiomyopathies and a leading cause of sudden cardiac death in young adults. Despite profound insights into the genetics, there is imperfect correlation between mutation and clinical prognosis, suggesting complex molecular cascades driving pathogenesis. To investigate this, we performed an integrated quantitative multi-omics (proteomic, phosphoproteomic, and metabolomic) analysis to illuminate the early and direct consequences of mutations in myosin heavy chain in engineered human induced pluripotent stem-cell-derived cardiomyocytes relative to late-stage disease using patient myectomies. We captured hundreds of differential features, which map to distinct molecular mechanisms modulating mitochondrial homeostasis at the earliest stages of pathobiology, as well as stage-specific metabolic and excitation-coupling maladaptation. Collectively, this study fills in gaps from previous studies by expanding knowledge of the initial responses to mutations that protect cells against the early stress prior to contractile dysfunction and overt disease.
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Yoo SH. Circadian regulation of cardiac muscle function and protein degradation. Chronobiol Int 2023; 40:4-12. [PMID: 34521283 PMCID: PMC8918439 DOI: 10.1080/07420528.2021.1957911] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Revised: 07/12/2021] [Accepted: 07/13/2021] [Indexed: 10/20/2022]
Abstract
The circadian clock plays a fundamental role in physiology. In particular, the heart is a target organ where the clock orchestrates various aspects of cardiac function. At the molecular level, the clock machinery governs daily rhythms of gene expression. Such circadian regulation is in tune with the dynamic nature of heart structure and function, and provides the foundation for chronotherapeutic applications in cardiovascular diseases. In comparison, a regulatory role of the clock in cardiac protein degradation is poorly documented. Sarcomere is the structural and functional unit responsible for cardiac muscle contraction, and sarcomere components are closely regulated by protein folding and proteolysis. Emerging evidence supports a role of the circadian clock in governing sarcomere integrity and function. Particularly, recent studies uncovered a circadian regulation of a core sarcomere component TCAP. It is possible that circadian regulation of the cardiac muscle protein turnover is a key regulatory mechanism underlying cardiac remodeling in response to physiological and environmental stimuli. While the detailed regulatory mechanisms and the molecular links to cardiac (patho)physiology remain to be further studied, therapeutic strategies targeting circadian control in the heart may markedly enhance intervention outcomes against cardiovascular disease.
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Affiliation(s)
- Seung-Hee Yoo
- Department of Biochemistry and Molecular Biology, The University of Texas Health Science Center at Houston, Houston, Texas, USA
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6
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Bogomolovas J, Gravenhorst P, Mayans O. Production and analysis of titin kinase: Exploiting active/inactive kinase homologs in pseudokinase validation. Methods Enzymol 2022; 667:147-181. [PMID: 35525541 DOI: 10.1016/bs.mie.2022.03.028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Protein pseudokinases are key regulators of the eukaryotic cell. Understanding their unconventional molecular mechanisms relies on deciphering their putative potential to perform phosphotransfer, their scaffolding properties and the nature of their regulation. Titin pseudokinase (TK) is the defining member of a family of poorly characterized muscle-specific kinases thought to act as sensors and transducers of mechanical signals in the sarcomere. The functional mechanisms of TK remain obscure due to the challenges posed by its production and analysis. Here, we provide guidelines and tailored research approaches for the study of TK, including profiting from its close structure-function relationship to the catalytically active homolog twitchin kinase (TwcK) from C. elegans. We describe a methodological pipeline to produce recombinant TK and TwcK samples; design, prioritize and validate mutated and truncated variants; assess sample stability and perform activity assays. The strategy is exportable to other pseudokinase members of the TK-like kinase family.
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Affiliation(s)
- Julius Bogomolovas
- School of Medicine, University of California, San Diego, La Jolla, CA, United States
| | | | - Olga Mayans
- Department of Biology, University of Konstanz, Konstanz, Germany.
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Cao X, Yan Y, Luo X, Yang X, Cui H, Yang Y, Li H. Analyses of the circadian clock genes expression in whole embryos and maternal major tissues of mice. J Mol Histol 2022; 53:473-482. [PMID: 35149920 DOI: 10.1007/s10735-022-10065-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Accepted: 02/02/2022] [Indexed: 10/19/2022]
Abstract
To create an organism, it is vital to assemble enough cells of the various differentiated types with the correct spatial arrangement within the embryo. Circadian clocks development is closely correlated with all cellular differentiation. However, the expression of its emergence during mammalian development are not fully understood. To determine whether embryonic development is influenced by circadian rhythm, it is necessary to observe the ontogeny of the circadian clock gene. We first measured the expression of key circadian genes in whole embryos and maternal major tissues of 25 female mice using RT-PCR and immunohistochemical analysis. Our results indicated that mouse embryos begin to express key circadian genes and have the capacity to express active circadian regulatory cycles during development. But circadian molecular rhythms can't be built in embryo. At E15, the expression of Bmal1, Clock and Per1 mRNA in whole embryo were increased, especially Per1. In the meanwhile, immunohistochemical analysis shows a small number of PER1 positive cells were observed in the bottom of right atrium. From E16 to E17, CLOCK and PER1 positive cells were observed in the airway smooth muscle, the wall of left atrium and skeletal muscle of body wall. It is interesting that CLOCK and PER1 positive cells could not be detected in the liver. By using RT-PCR, we continue to observe the expression of myogenic regulatory factor in embryos and also analyse the relationship of embryo development and maternal rhythms. From E12, the expression of myogenin increased quickly. The expression of Tcap at E15 significantly increased. myogenin may play a direct role in contributing Tcap expression. The expression of MAZ is always the highest than myogenin and Tcap in embryos. MAZ may concern with the development of skeletal muscle. The clock gene is a positive regulator of myogenesis and the development of organ. In contrast to embryonic tissues, circadian variation was present for Bmal1, Clock and Per1 at maternal tissues. Our results indicate that circadian clock genes seem to function differently in different tissues of embryo and maternal mice. Synchrony does not occur during embryo development despite exposure to maternal rhythms. But development of embryo may be affected by maternal tissues of mice.
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Affiliation(s)
- Ximei Cao
- Department of Histology and Embryology, Shanxi Medical University, 56 South Xinjian Nan Road, Taiyuan, 030001, Shanxi, China.
| | - Yindi Yan
- Department of Histology and Embryology, Shanxi Medical University, 56 South Xinjian Nan Road, Taiyuan, 030001, Shanxi, China
| | - Xuguang Luo
- Department of Microbiology and Immunology, Shanxi Medical University, Taiyuan, 030001, China
| | - Xinhua Yang
- Department of Histology and Embryology, Shanxi Medical University, 56 South Xinjian Nan Road, Taiyuan, 030001, Shanxi, China
| | - Huilin Cui
- Department of Histology and Embryology, Shanxi Medical University, 56 South Xinjian Nan Road, Taiyuan, 030001, Shanxi, China
| | - Yanping Yang
- Department of Histology and Embryology, Shanxi Medical University, 56 South Xinjian Nan Road, Taiyuan, 030001, Shanxi, China
| | - Hairong Li
- Department of Histology and Embryology, Shanxi Medical University, 56 South Xinjian Nan Road, Taiyuan, 030001, Shanxi, China
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8
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Soetkamp D, Gallet R, Parker SJ, Holewinski R, Venkatraman V, Peck K, Goldhaber JI, Marbán E, Van Eyk JE. Myofilament Phosphorylation in Stem Cell Treated Diastolic Heart Failure. Circ Res 2021; 129:1125-1140. [PMID: 34641704 DOI: 10.1161/circresaha.119.316311] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
RATIONALE Phosphorylation of sarcomeric proteins has been implicated in heart failure with preserved ejection fraction (HFpEF); such changes may contribute to diastolic dysfunction by altering contractility, cardiac stiffness, Ca2+-sensitivity, and mechanosensing. Treatment with cardiosphere-derived cells (CDCs) restores normal diastolic function, attenuates fibrosis and inflammation, and improves survival in a rat HFpEF model. OBJECTIVE Phosphorylation changes that underlie HFpEF and those reversed by CDC therapy, with a focus on the sarcomeric subproteome were analyzed. METHODS AND RESULTS Dahl salt-sensitive rats fed a high-salt diet, with echocardiographically verified diastolic dysfunction, were randomly assigned to either intracoronary CDCs or placebo. Dahl salt-sensitive rats receiving low salt diet served as controls. Protein and phosphorylated Ser, Thr, and Tyr residues from left ventricular tissue were quantified by mass spectrometry. HFpEF hearts exhibited extensive hyperphosphorylation with 98% of the 529 significantly changed phospho-sites increased compared with control. Of those, 39% were located within the sarcomeric subproteome, with a large group of proteins located or associated with the Z-disk. CDC treatment partially reverted the hyperphosphorylation, with 85% of the significantly altered 76 residues hypophosphorylated. Bioinformatic upstream analysis of the differentially phosphorylated protein residues revealed PKC as the dominant putative regulatory kinase. PKC isoform analysis indicated increases in PKC α, β, and δ concentration, whereas CDC treatment led to a reversion of PKCβ. Use of PKC isoform specific inhibition and overexpression of various PKC isoforms strongly suggests that PKCβ is the dominant kinase involved in hyperphosphorylation in HFpEF and is altered with CDC treatment. CONCLUSIONS Increased protein phosphorylation at the Z-disk is associated with diastolic dysfunction, with PKC isoforms driving most quantified phosphorylation changes. Because CDCs reverse the key abnormalities in HFpEF and selectively reverse PKCβ upregulation, PKCβ merits being classified as a potential therapeutic target in HFpEF, a disease notoriously refractory to medical intervention.
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Affiliation(s)
- Daniel Soetkamp
- Smidt Heart Institute, Cedars-Sinai Medical Center, Los Angeles, CA
| | - Romain Gallet
- Smidt Heart Institute, Cedars-Sinai Medical Center, Los Angeles, CA
| | - Sarah J Parker
- Smidt Heart Institute, Cedars-Sinai Medical Center, Los Angeles, CA
| | | | | | - Kiel Peck
- Smidt Heart Institute, Cedars-Sinai Medical Center, Los Angeles, CA
| | | | - Eduardo Marbán
- Smidt Heart Institute, Cedars-Sinai Medical Center, Los Angeles, CA
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Solís C, Russell B. Striated muscle proteins are regulated both by mechanical deformation and by chemical post-translational modification. Biophys Rev 2021; 13:679-695. [PMID: 34777614 PMCID: PMC8555064 DOI: 10.1007/s12551-021-00835-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Accepted: 08/23/2021] [Indexed: 01/09/2023] Open
Abstract
All cells sense force and build their cytoskeleton to optimize function. How is this achieved? Two major systems are involved. The first is that load deforms specific protein structures in a proportional and orientation-dependent manner. The second is post-translational modification of proteins as a consequence of signaling pathway activation. These two processes work together in a complex way so that local subcellular assembly as well as overall cell function are controlled. This review discusses many cell types but focuses on striated muscle. Detailed information is provided on how load deforms the structure of proteins in the focal adhesions and filaments, using α-actinin, vinculin, talin, focal adhesion kinase, LIM domain-containing proteins, filamin, myosin, titin, and telethonin as examples. Second messenger signals arising from external triggers are distributed throughout the cell causing post-translational or chemical modifications of protein structures, with the actin capping protein CapZ and troponin as examples. There are numerous unanswered questions of how mechanical and chemical signals are integrated by muscle proteins to regulate sarcomere structure and function yet to be studied. Therefore, more research is needed to see how external triggers are integrated with local tension generated within the cell. Nonetheless, maintenance of tension in the sarcomere is the essential and dominant mechanism, leading to the well-known phrase in exercise physiology: "use it or lose it."
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Affiliation(s)
- Christopher Solís
- Department of Physiology and Biophysics, College of Medicine, University of Illinois at Chicago, Chicago, IL 60612 USA
| | - Brenda Russell
- Department of Physiology and Biophysics, College of Medicine, University of Illinois at Chicago, Chicago, IL 60612 USA
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10
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Wirianto M, Yang J, Kim E, Gao S, Paudel KR, Choi JM, Choe J, Gloston GF, Ademoji P, Parakramaweera R, Jin J, Esser KA, Jung SY, Geng YJ, Lee HK, Chen Z, Yoo SH. The GSK-3β-FBXL21 Axis Contributes to Circadian TCAP Degradation and Skeletal Muscle Function. Cell Rep 2021; 32:108140. [PMID: 32937135 PMCID: PMC8299398 DOI: 10.1016/j.celrep.2020.108140] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Revised: 01/04/2020] [Accepted: 08/21/2020] [Indexed: 12/19/2022] Open
Abstract
FBXL21 is a clock-controlled E3 ligase modulating circadian periodicity via subcellular-specific CRYPTOCHROME degradation. How FBXL21 regulates tissue-specific circadian physiology and what mechanism operates upstream is poorly understood. Here we report the sarcomere component TCAP as a cytoplasmic substrate of FBXL21. FBXL21 interacts with TCAP in a circadian manner antiphasic to TCAP accumulation in skeletal muscle, and circadian TCAP oscillation is disrupted in Psttm mice with an Fbxl21 hypomorph mutation. GSK-3β phosphorylates FBXL21 and TCAP to activate FBXL21-mediated, phosphodegron-dependent TCAP degradation. GSK-3β inhibition or knockdown diminishes FBXL21-Cul1 complex formation and delays FBXL21-mediated TCAP degradation. Finally, Psttm mice show significant skeletal muscle defects, including impaired fiber size, exercise tolerance, grip strength, and response to glucocorticoid-induced atrophy, in conjunction with cardiac dysfunction. These data highlight a circadian regulatory pathway where a GSK-3β-FBXL21 functional axis controls TCAP degradation via SCF complex formation and regulates skeletal muscle function. Wirianto et al. find that the circadian E3 ligase FBXL21 drives rhythmic degradation of the sarcomeric protein TCAP in skeletal muscle. GSK-3β co-phosphorylates FBXL21 and TCAP and promotes SCF complex formation and phosphodegron-dependent TCAP turnover. Psttm mice, expressing a hypomorphic Fbxl21 mutant, show dysregulated TCAP degradation and impaired muscle function.
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Affiliation(s)
- Marvin Wirianto
- Department of Biochemistry and Molecular Biology, The University of Texas Health Science Center at Houston, 6431 Fannin St., Houston, TX 77030, USA
| | - Jiah Yang
- Department of Biochemistry and Molecular Biology, The University of Texas Health Science Center at Houston, 6431 Fannin St., Houston, TX 77030, USA
| | - Eunju Kim
- Department of Biochemistry and Molecular Biology, The University of Texas Health Science Center at Houston, 6431 Fannin St., Houston, TX 77030, USA
| | - Song Gao
- Department of Internal Medicine, The University of Texas Health Science Center at Houston, 6431 Fannin St., Houston, TX 77030, USA
| | - Keshav Raj Paudel
- Department of Biochemistry and Molecular Biology, The University of Texas Health Science Center at Houston, 6431 Fannin St., Houston, TX 77030, USA
| | - Jong Min Choi
- Department of Biochemistry and Molecular Biology, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA
| | - Jeehwan Choe
- Department of Biochemistry and Molecular Biology, The University of Texas Health Science Center at Houston, 6431 Fannin St., Houston, TX 77030, USA
| | - Gabrielle F Gloston
- Department of Biochemistry and Molecular Biology, The University of Texas Health Science Center at Houston, 6431 Fannin St., Houston, TX 77030, USA
| | - Precious Ademoji
- Department of Biochemistry and Molecular Biology, The University of Texas Health Science Center at Houston, 6431 Fannin St., Houston, TX 77030, USA
| | - Randika Parakramaweera
- Department of Biochemistry and Molecular Biology, The University of Texas Health Science Center at Houston, 6431 Fannin St., Houston, TX 77030, USA
| | - Jianping Jin
- Department of Biochemistry and Molecular Biology, The University of Texas Health Science Center at Houston, 6431 Fannin St., Houston, TX 77030, USA
| | - Karyn A Esser
- Department of Physiology and Functional Genomics, The University of Florida College of Medicine, Gainesville, FL 32610-0274, USA
| | - Sung Yun Jung
- Department of Biochemistry and Molecular Biology, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA
| | - Yong-Jian Geng
- Department of Internal Medicine, The University of Texas Health Science Center at Houston, 6431 Fannin St., Houston, TX 77030, USA
| | - Hyun Kyoung Lee
- Department of Pediatrics, Baylor College of Medicine, Houston, TX 77030, USA; Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX 77030, USA
| | - Zheng Chen
- Department of Biochemistry and Molecular Biology, The University of Texas Health Science Center at Houston, 6431 Fannin St., Houston, TX 77030, USA
| | - Seung-Hee Yoo
- Department of Biochemistry and Molecular Biology, The University of Texas Health Science Center at Houston, 6431 Fannin St., Houston, TX 77030, USA.
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11
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Solís C, Solaro RJ. Novel insights into sarcomere regulatory systems control of cardiac thin filament activation. J Gen Physiol 2021; 153:211903. [PMID: 33740037 PMCID: PMC7988513 DOI: 10.1085/jgp.202012777] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Accepted: 02/23/2021] [Indexed: 12/11/2022] Open
Abstract
Our review focuses on sarcomere regulatory mechanisms with a discussion of cardiac-specific modifications to the three-state model of thin filament activation from a blocked to closed to open state. We discuss modulation of these thin filament transitions by Ca2+, by crossbridge interactions, and by thick filament–associated proteins, cardiac myosin–binding protein C (cMyBP-C), cardiac regulatory light chain (cRLC), and titin. Emerging evidence supports the idea that the cooperative activation of the thin filaments despite a single Ca2+ triggering regulatory site on troponin C (cTnC) cannot be considered in isolation of other functional domains of the sarcomere. We discuss long- and short-range interactions among these domains with the regulatory units of thin filaments, including proteins at the barbed end at the Z-disc and the pointed end near the M-band. Important to these discussions is the ever-increasing understanding of the role of cMyBP-C, cRLC, and titin filaments. Detailed knowledge of these control processes is critical to the understanding of mechanisms sustaining physiological cardiac state with varying hemodynamic load, to better defining genetic and acquired cardiac disorders, and to developing targets for therapies at the level of the sarcomeres.
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Affiliation(s)
- Christopher Solís
- University of Illinois at Chicago, College of Medicine, Department of Physiology and Biophysics and Center for Cardiovascular Research, Chicago, IL
| | - R John Solaro
- University of Illinois at Chicago, College of Medicine, Department of Physiology and Biophysics and Center for Cardiovascular Research, Chicago, IL
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12
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Jiang H, Hooper C, Kelly M, Steeples V, Simon JN, Beglov J, Azad AJ, Leinhos L, Bennett P, Ehler E, Kalisch-Smith JI, Sparrow DB, Fischer R, Heilig R, Isackson H, Ehsan M, Patone G, Huebner N, Davies B, Watkins H, Gehmlich K. Functional analysis of a gene-edited mouse model to gain insights into the disease mechanisms of a titin missense variant. Basic Res Cardiol 2021; 116:14. [PMID: 33637999 PMCID: PMC7910237 DOI: 10.1007/s00395-021-00853-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Accepted: 02/10/2021] [Indexed: 11/03/2022]
Abstract
Titin truncating variants are a well-established cause of cardiomyopathy; however, the role of titin missense variants is less well understood. Here we describe the generation of a mouse model to investigate the underlying disease mechanism of a previously reported titin A178D missense variant identified in a family with non-compaction and dilated cardiomyopathy. Heterozygous and homozygous mice carrying the titin A178D missense variant were characterised in vivo by echocardiography. Heterozygous mice had no detectable phenotype at any time point investigated (up to 1 year). By contrast, homozygous mice developed dilated cardiomyopathy from 3 months. Chronic adrenergic stimulation aggravated the phenotype. Targeted transcript profiling revealed induction of the foetal gene programme and hypertrophic signalling pathways in homozygous mice, and these were confirmed at the protein level. Unsupervised proteomics identified downregulation of telethonin and four-and-a-half LIM domain 2, as well as the upregulation of heat shock proteins and myeloid leukaemia factor 1. Loss of telethonin from the cardiac Z-disc was accompanied by proteasomal degradation; however, unfolded telethonin accumulated in the cytoplasm, leading to a proteo-toxic response in the mice.We show that the titin A178D missense variant is pathogenic in homozygous mice, resulting in cardiomyopathy. We also provide evidence of the disease mechanism: because the titin A178D variant abolishes binding of telethonin, this leads to its abnormal cytoplasmic accumulation. Subsequent degradation of telethonin by the proteasome results in proteasomal overload, and activation of a proteo-toxic response. The latter appears to be a driving factor for the cardiomyopathy observed in the mouse model.
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Affiliation(s)
- He Jiang
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine and British Heart Foundation Centre of Research Excellence Oxford, University of Oxford, Oxford, OX3 9DU, UK
| | - Charlotte Hooper
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine and British Heart Foundation Centre of Research Excellence Oxford, University of Oxford, Oxford, OX3 9DU, UK
| | - Matthew Kelly
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine and British Heart Foundation Centre of Research Excellence Oxford, University of Oxford, Oxford, OX3 9DU, UK
| | - Violetta Steeples
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine and British Heart Foundation Centre of Research Excellence Oxford, University of Oxford, Oxford, OX3 9DU, UK
| | - Jillian N Simon
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine and British Heart Foundation Centre of Research Excellence Oxford, University of Oxford, Oxford, OX3 9DU, UK
| | - Julia Beglov
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine and British Heart Foundation Centre of Research Excellence Oxford, University of Oxford, Oxford, OX3 9DU, UK
| | - Amar J Azad
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine and British Heart Foundation Centre of Research Excellence Oxford, University of Oxford, Oxford, OX3 9DU, UK
| | - Lisa Leinhos
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine and British Heart Foundation Centre of Research Excellence Oxford, University of Oxford, Oxford, OX3 9DU, UK
| | - Pauline Bennett
- Randall Centre for Cell and Molecular Biophysics, School of Cardiovascular Medicine and Sciences, King's College London BHF Centre of Research Excellence, London, UK
| | - Elisabeth Ehler
- Randall Centre for Cell and Molecular Biophysics, School of Cardiovascular Medicine and Sciences, King's College London BHF Centre of Research Excellence, London, UK
| | | | - Duncan B Sparrow
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK
| | - Roman Fischer
- Nuffield Department of Clinical Medicine, Target Discovery Institute, University of Oxford, Oxford, UK
| | - Raphael Heilig
- Nuffield Department of Clinical Medicine, Target Discovery Institute, University of Oxford, Oxford, UK
| | - Henrik Isackson
- Department of Medical Sciences, Cardiology, Uppsala University, Uppsala, Sweden
- Department of Medical Cell Biology, Integrative Physiology, Uppsala University, Uppsala, Sweden
| | - Mehroz Ehsan
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine and British Heart Foundation Centre of Research Excellence Oxford, University of Oxford, Oxford, OX3 9DU, UK
| | - Giannino Patone
- Max Delbrueck Centre for Molecular Medicine, Berlin, Germany
| | - Norbert Huebner
- Max Delbrueck Centre for Molecular Medicine, Berlin, Germany
| | - Benjamin Davies
- Transgenic Core, Wellcome Centre for Human Genetics, University of Oxford, Oxford, UK
| | - Hugh Watkins
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine and British Heart Foundation Centre of Research Excellence Oxford, University of Oxford, Oxford, OX3 9DU, UK
| | - Katja Gehmlich
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine and British Heart Foundation Centre of Research Excellence Oxford, University of Oxford, Oxford, OX3 9DU, UK.
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, B15 2TT, UK.
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13
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Russell B, Solís C. Mechanosignaling pathways alter muscle structure and function by post-translational modification of existing sarcomeric proteins to optimize energy usage. J Muscle Res Cell Motil 2021; 42:367-380. [PMID: 33595762 DOI: 10.1007/s10974-021-09596-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Accepted: 01/04/2021] [Indexed: 12/29/2022]
Abstract
A transduced mechanical signal arriving at its destination in muscle alters sarcomeric structure and function. A major question addressed is how muscle mass and tension generation are optimized to match actual performance demands so that little energy is wasted. Three cases for improved energy efficiency are examined: the troponin complex for tuning force production, control of the myosin heads in a resting state, and the Z-disc proteins for sarcomere assembly. On arrival, the regulation of protein complexes is often controlled by post-translational modification (PTM), of which the most common are phosphorylation by kinases, deacetylation by histone deacetylases and ubiquitination by E3 ligases. Another branch of signals acts not through peptide covalent bonding but via ligand interactions (e.g. Ca2+ and phosphoinositide binding). The myosin head and the regulation of its binding to actin by the troponin complex is the best and earliest example of signal destinations that modify myofibrillar contractility. PTMs in the troponin complex regulate both the efficiency of the contractile function to match physiologic demand for work, and muscle mass via protein degradation. The regulation of sarcomere assembly by integration of incoming signaling pathways causing the same PTMs or ligand binding are discussed in response to mechanical loading and unloading by the Z-disc proteins CapZ, α-actinin, telethonin, titin N-termini, and others. Many human mutations that lead to cardiomyopathy and heart disease occur in the proteins discussed above, which often occur at their PTM or ligand binding sites.
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Affiliation(s)
- Brenda Russell
- Department of Physiology and Biophysics, College of Medicine, University of Illinois at Chicago, Chicago, IL, 60612, USA.
| | - Christopher Solís
- Department of Physiology and Biophysics, College of Medicine, University of Illinois at Chicago, Chicago, IL, 60612, USA
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14
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Lewis HR, Eminaga S, Gautel M, Avkiran M. Phosphorylation at Serines 157 and 161 Is Necessary for Preserving Cardiac Expression Level and Functions of Sarcomeric Z-Disc Protein Telethonin. Front Physiol 2021; 12:732020. [PMID: 34566695 PMCID: PMC8455888 DOI: 10.3389/fphys.2021.732020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Accepted: 08/16/2021] [Indexed: 11/13/2022] Open
Abstract
Aims: In cardiac myocytes, the sarcomeric Z-disc protein telethonin is constitutively bis-phosphorylated at C-terminal residues S157 and S161; however, the functional significance of this phosphorylation is not known. We sought to assess the significance of telethonin phosphorylation in vivo, using a novel knock-in (KI) mouse model generated to express non-phosphorylatable telethonin (Tcap S157/161A). Methods and Results: Tcap S157/161A and wild-type (WT) littermates were characterized by echocardiography at baseline and after sustained β-adrenergic stimulation via isoprenaline infusion. Heart tissues were collected for gravimetric, biochemical, and histological analyses. At baseline, Tcap S157/161A mice did not show any variances in cardiac structure or function compared with WT littermates and mutant telethonin remained localized to the Z-disc. Ablation of telethonin phosphorylation sites resulted in a gene-dosage dependent decrease in the cardiac telethonin protein expression level in mice carrying the S157/161A alleles, without any alteration in telethonin mRNA levels. The proteasome inhibitor MG132 significantly increased the expression level of S157/161A telethonin protein in myocytes from Tcap S157/161A mice, but not telethonin protein in myocytes from WT mice, indicating a role for the ubiquitin-proteasome system in the regulation of telethonin protein expression level. Tcap S157/161A mice challenged with sustained β-adrenergic stimulation via isoprenaline infusion developed cardiac hypertrophy accompanied by mild systolic dysfunction. Furthermore, the telethonin protein expression level was significantly increased in WT mice following isoprenaline stimulation but this response was blunted in Tcap S157/161A mice. Conclusion: Overall, these data reveal that telethonin protein turnover in vivo is regulated in a novel phosphorylation-dependent manner and suggest that C-terminal phosphorylation may protect telethonin against proteasomal degradation and preserve cardiac function during hemodynamic stress. Given that human telethonin C-terminal mutations have been associated with cardiac and skeletal myopathies, further research on their potential impact on phosphorylation-dependent regulation of telethonin protein expression could provide valuable mechanistic insight into those myopathies.
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Affiliation(s)
- Hannah R. Lewis
- School of Cardiovascular Medicine and Sciences, St Thomas’ Hospital, King’s College London British Heart Foundation Centre of Research Excellence, London, United Kingdom
| | - Seda Eminaga
- School of Cardiovascular Medicine and Sciences, St Thomas’ Hospital, King’s College London British Heart Foundation Centre of Research Excellence, London, United Kingdom
| | - Mathias Gautel
- School of Basic and Medical Biosciences, Guy’s Hospital, King’s College London British Heart Foundation Centre of Research Excellence, London, United Kingdom
| | - Metin Avkiran
- School of Cardiovascular Medicine and Sciences, St Thomas’ Hospital, King’s College London British Heart Foundation Centre of Research Excellence, London, United Kingdom
- *Correspondence: Metin Avkiran,
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15
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Distal myopathy due to TCAP variants in four unrelated Chinese patients. Neurogenetics 2020; 22:1-10. [PMID: 32761539 DOI: 10.1007/s10048-020-00623-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Accepted: 08/01/2020] [Indexed: 10/23/2022]
Abstract
Distal myopathies are a group of clinically and genetically heterogeneous hereditary muscle disorders characterized by progressive muscular weakness starting in the distal parts of the limbs. The most common subtype of distal myopathy is GNE myopathy, a rare muscle disease with autosomal recessive inheritance. Limb-girdle muscular dystrophy 2G (LGMD2G) is a rare autosomal recessive subtype of LGMDs caused by TCAP variant. Patients with LGMD2G can present with distal myopathy and rimmed vacuoles on muscle pathology. Thus far, the most reported TCAP mutations related to LGMD2G were recessive frameshift or nonsense variants. Here, we described four Chinese patients from unrelated families with LGMD2G due to TCAP mutations. The clinical symptoms of our patients were similar to those previously reported in LGMD2G patients. Three different pathogenic TCAP variants were identified in these patients, including two frameshift variants and one intronic variant. Autophagolysosomes have been observed in one patient by electron microscopy. Our research expands the genetic spectrum of TCAP mutations in China, indicating c.165-166insG is likely the common pathogenic variant. We also provide evidences that autophagy may be involved in the pathophysiology of LGMD2G.
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16
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Puhl SL, Weeks KL, Güran A, Ranieri A, Boknik P, Kirchhefer U, Müller FU, Avkiran M. Role of type 2A phosphatase regulatory subunit B56α in regulating cardiac responses to β-adrenergic stimulation in vivo. Cardiovasc Res 2020; 115:519-529. [PMID: 30203051 PMCID: PMC6383118 DOI: 10.1093/cvr/cvy230] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Revised: 07/26/2018] [Accepted: 09/07/2018] [Indexed: 12/11/2022] Open
Abstract
AIMS B56α is a protein phosphatase 2A (PP2A) regulatory subunit that is highly expressed in the heart. We previously reported that cardiomyocyte B56α localizes to myofilaments under resting conditions and translocates to the cytosol in response to acute β-adrenergic receptor (β-AR) stimulation. Given the importance of reversible protein phosphorylation in modulating cardiac function during sympathetic stimulation, we hypothesized that loss of B56α in mice with targeted disruption of the gene encoding B56α (Ppp2r5a) would impact on cardiac responses to β-AR stimulation in vivo. METHODS AND RESULTS Cardiac phenotype of mice heterozygous (HET) or homozygous (HOM) for the disrupted Ppp2r5a allele and wild type (WT) littermates was characterized under basal conditions and following acute β-AR stimulation with dobutamine (DOB; 0.75 mg/kg i.p.) or sustained β-AR stimulation by 2-week infusion of isoproterenol (ISO; 30 mg/kg/day s.c.). Left ventricular (LV) wall thicknesses, chamber dimensions and function were assessed by echocardiography, and heart tissue collected for gravimetric, histological, and biochemical analyses. Western blot analysis revealed partial and complete loss of B56α protein in hearts from HET and HOM mice, respectively, and no changes in the expression of other PP2A regulatory, catalytic or scaffolding subunits. PP2A catalytic activity was reduced in hearts of both HET and HOM mice. There were no differences in the basal cardiac phenotype between genotypes. Acute DOB stimulation induced the expected inotropic response in WT and HET mice, which was attenuated in HOM mice. In contrast, DOB-induced increases in heart rate were unaffected by B56α deficiency. In WT mice, ISO infusion increased LV wall thicknesses, cardiomyocyte area and ventricular mass, without LV dilation, systolic dysfunction, collagen deposition or foetal gene expression. The hypertrophic response to ISO was blunted in mice deficient for B56α. CONCLUSION These findings identify B56α as a potential regulator of cardiac structure and function during β-AR stimulation.
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Affiliation(s)
- Sarah-Lena Puhl
- School of Cardiovascular Medicine and Sciences, King's College London British Heart Foundation Centre of Research Excellence, St Thomas' Hospital, Westminster Bridge Road, London, UK.,Institute for Cardiovascular Prevention, Ludwig-Maximilians-University, Pettenkoferstrasse 9b, D-80336 Munich, Germany
| | - Kate L Weeks
- School of Cardiovascular Medicine and Sciences, King's College London British Heart Foundation Centre of Research Excellence, St Thomas' Hospital, Westminster Bridge Road, London, UK.,Baker Heart and Diabetes Institute, 75 Commercial Road, Melbourne, VIC, Australia
| | - Alican Güran
- School of Cardiovascular Medicine and Sciences, King's College London British Heart Foundation Centre of Research Excellence, St Thomas' Hospital, Westminster Bridge Road, London, UK
| | - Antonella Ranieri
- School of Cardiovascular Medicine and Sciences, King's College London British Heart Foundation Centre of Research Excellence, St Thomas' Hospital, Westminster Bridge Road, London, UK
| | - Peter Boknik
- Institut für Pharmakologie und Toxikologie, Universitätsklinikum Münster, Domagkstrasse 12, D-48149 Münster, Germany
| | - Uwe Kirchhefer
- Institut für Pharmakologie und Toxikologie, Universitätsklinikum Münster, Domagkstrasse 12, D-48149 Münster, Germany
| | - Frank U Müller
- Institut für Pharmakologie und Toxikologie, Universitätsklinikum Münster, Domagkstrasse 12, D-48149 Münster, Germany
| | - Metin Avkiran
- School of Cardiovascular Medicine and Sciences, King's College London British Heart Foundation Centre of Research Excellence, St Thomas' Hospital, Westminster Bridge Road, London, UK
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17
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Tyganov SA, Mochalova EP, Belova SP, Sharlo KA, Rozhkov SV, Vilchinskaya NA, Paramonova II, Mirzoev TM, Shenkman BS. Effects of Plantar Mechanical Stimulation on Anabolic and Catabolic Signaling in Rat Postural Muscle Under Short-Term Simulated Gravitational Unloading. Front Physiol 2019; 10:1252. [PMID: 31611819 PMCID: PMC6776874 DOI: 10.3389/fphys.2019.01252] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Accepted: 09/12/2019] [Indexed: 12/18/2022] Open
Abstract
It is known that plantar mechanical stimulation (PMS) is able to attenuate unloading-induced skeletal muscle atrophy and impaired muscle function. However, molecular mechanisms underlying the effect of PMS on skeletal muscle during unloading remain undefined. The aim of the study was to evaluate the effects of PMS on anabolic and catabolic signaling pathways in rat soleus at the early stages of mechanical unloading. Wistar rats were randomly assigned to ambulatory control, hindlimb suspension (HS) for 1 or 3 days, and HS for 1 or 3 days with PMS. The key anabolic and catabolic markers were assessed by western blotting and RT-PCR. Protein synthesis (PS) rate was estimated using SUnSET technique. PMS attenuated a 1-day HS-induced decrease in 4E-BP1, GSK-3β, and AMPK phosphorylation. PMS also partially prevented a decrease in PS, phosphorylation of GSK-3β, nNOS, and an increase in eEF2 phosphorylation after 3-day HS. PMS during 1- and 3-day HS prevented MuRF-1, but not MAFbx, upregulation but did not affect markers of ribosome biogenesis (18S + 28S rRNA, c-myc) as well as AKT phosphorylation. Thus, PMS during 3-day HS partially prevented a decrease in the global rate of PS in rat soleus muscle, which was accompanied by attenuation of MuRF-1 mRNA expression as well as changes in GSK-3β, nNOS, and eEF2 phosphorylation.
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Affiliation(s)
- Sergey A Tyganov
- Myology Laboratory, Institute of Biomedical Problems, Russian Academy of Sciences, Moscow, Russia
| | - Ekaterina P Mochalova
- Myology Laboratory, Institute of Biomedical Problems, Russian Academy of Sciences, Moscow, Russia
| | - Svetlana P Belova
- Myology Laboratory, Institute of Biomedical Problems, Russian Academy of Sciences, Moscow, Russia
| | - Kristina A Sharlo
- Myology Laboratory, Institute of Biomedical Problems, Russian Academy of Sciences, Moscow, Russia
| | - Sergey V Rozhkov
- Myology Laboratory, Institute of Biomedical Problems, Russian Academy of Sciences, Moscow, Russia
| | - Natalia A Vilchinskaya
- Myology Laboratory, Institute of Biomedical Problems, Russian Academy of Sciences, Moscow, Russia
| | - Inna I Paramonova
- Myology Laboratory, Institute of Biomedical Problems, Russian Academy of Sciences, Moscow, Russia
| | - Timur M Mirzoev
- Myology Laboratory, Institute of Biomedical Problems, Russian Academy of Sciences, Moscow, Russia
| | - Boris S Shenkman
- Myology Laboratory, Institute of Biomedical Problems, Russian Academy of Sciences, Moscow, Russia
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18
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Polge C, Cabantous S, Deval C, Claustre A, Hauvette A, Bouchenot C, Aniort J, Béchet D, Combaret L, Attaix D, Taillandier D. A muscle-specific MuRF1-E2 network requires stabilization of MuRF1-E2 complexes by telethonin, a newly identified substrate. J Cachexia Sarcopenia Muscle 2018; 9:129-145. [PMID: 29271608 PMCID: PMC5803617 DOI: 10.1002/jcsm.12249] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/18/2017] [Revised: 08/21/2017] [Accepted: 09/05/2017] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Muscle wasting is observed in the course of many diseases and also during physiological conditions (disuse, ageing). Skeletal muscle mass is largely controlled by the ubiquitin-proteasome system and thus by the ubiquitinating enzymes (E2s and E3s) that target substrates for subsequent degradation. MuRF1 is the only E3 ubiquitin ligase known to target contractile proteins (α-actin, myosins) during catabolic situations. However, MuRF1 depends on E2 ubiquitin-conjugating enzymes for ubiquitin chain formation on the substrates. MuRF1-E2 couples are therefore putative targets for preventing muscle wasting. METHODS We focused on 14 E2 enzymes that are either expressed in skeletal muscle or up-regulated during atrophying conditions. In this work, we demonstrated that only highly sensitive and complementary interactomic approaches (surface plasmon resonance, yeast three-hybrid, and split green fluorescent protein) allowed the identification of MuRF1 E2 partners. RESULTS Five E2 enzymes physically interacted with MuRF1, namely, E2E1, E2G1, E2J1, E2J2, and E2L3. Moreover, we demonstrated that MuRF1-E2E1 and MuRF1-E2J1 interactions are facilitated by telethonin, a newly identified MuRF1 substrate. We next showed that the five identified E2s functionally interacted with MuRF1 since, in contrast to the non-interacting E2D2, their co-expression in HEK293T cells with MuRF1 led to increased telethonin degradation. Finally, we showed that telethonin governed the affinity between MuRF1 and E2E1 or E2J1. CONCLUSIONS We report here the first MuRF1-E2s network, which may prove valuable for deciphering the precise mechanisms involved in the atrophying muscle programme and for proposing new therapeutical approaches.
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Affiliation(s)
- Cécile Polge
- Université Clermont Auvergne, INRA, UNH, Unité de Nutrition HumaineCRNH AuvergneF‐63000Clermont‐FerrandFrance
| | - Stéphanie Cabantous
- Cancer Research Center of Toulouse, INSERM UMR 1037F‐31037ToulouseFrance
- Université de ToulouseF‐31062ToulouseFrance
| | - Christiane Deval
- Université Clermont Auvergne, INRA, UNH, Unité de Nutrition HumaineCRNH AuvergneF‐63000Clermont‐FerrandFrance
| | - Agnès Claustre
- Université Clermont Auvergne, INRA, UNH, Unité de Nutrition HumaineCRNH AuvergneF‐63000Clermont‐FerrandFrance
| | - Antoine Hauvette
- Université Clermont Auvergne, INRA, UNH, Unité de Nutrition HumaineCRNH AuvergneF‐63000Clermont‐FerrandFrance
| | - Catherine Bouchenot
- Cancer Research Center of Toulouse, INSERM UMR 1037F‐31037ToulouseFrance
- Université de ToulouseF‐31062ToulouseFrance
| | - Julien Aniort
- Université Clermont Auvergne, INRA, UNH, Unité de Nutrition HumaineCRNH AuvergneF‐63000Clermont‐FerrandFrance
- Service de Néphrologie Réanimation Médicale, Pôle Respiratoire, Endocrinologie‐Diabétologie, Urologie, Néphrologie‐Dialyse, Nutrition Clinique, InfectiologieRéanimation Médicale, Hygiène Hospitalière (REUNNIRH)F‐63000Clermont‐FerrandFrance
| | - Daniel Béchet
- Université Clermont Auvergne, INRA, UNH, Unité de Nutrition HumaineCRNH AuvergneF‐63000Clermont‐FerrandFrance
| | - Lydie Combaret
- Université Clermont Auvergne, INRA, UNH, Unité de Nutrition HumaineCRNH AuvergneF‐63000Clermont‐FerrandFrance
| | - Didier Attaix
- Université Clermont Auvergne, INRA, UNH, Unité de Nutrition HumaineCRNH AuvergneF‐63000Clermont‐FerrandFrance
| | - Daniel Taillandier
- Université Clermont Auvergne, INRA, UNH, Unité de Nutrition HumaineCRNH AuvergneF‐63000Clermont‐FerrandFrance
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19
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Ranieri A, Kemp E, Burgoyne JR, Avkiran M. β-Adrenergic regulation of cardiac type 2A protein phosphatase through phosphorylation of regulatory subunit B56δ at S573. J Mol Cell Cardiol 2017; 115:20-31. [PMID: 29294329 PMCID: PMC5823843 DOI: 10.1016/j.yjmcc.2017.12.016] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/02/2017] [Revised: 12/19/2017] [Accepted: 12/29/2017] [Indexed: 11/18/2022]
Abstract
Background Type 2A protein phosphatase (PP2A) enzymes are serine/threonine phosphatases which comprise a scaffold A subunit, a regulatory B subunit and a catalytic C subunit, and have been implicated in the dephosphorylation of multiple cardiac phosphoproteins. B subunits determine subcellular targeting, substrate specificity and catalytic activity, and can themselves be regulated by post-translational modifications. We explored potential β-adrenergic regulation of PP2A in cardiomyocytes through phosphorylation of the regulatory B subunit isoform B56δ. Methods and results Phosphate affinity SDS-PAGE and immunoblot analysis revealed increased phosphorylation of B56δ in adult rat ventricular myocytes (ARVM) exposed to the β-adrenergic receptor (βAR) agonist isoprenaline (ISO). Phosphorylation of B56δ occurred at S573, primarily through stimulation of the β1AR subtype, and was dependent on PKA activity. The functional role of the phosphorylation was explored in ARVM transduced with adenoviruses expressing wild type (WT) or non-phosphorylatable (S573A) B56δ, fused to GFP at the N-terminus. C subunit expression was increased in ARVM expressing GFP-B56δ-WT or GFP-B56δ-S573A, both of which co-immunoprecipitated with endogenous C and A subunits. PP2A activity in cell lysates was increased in response to ISO in ARVM expressing GFP-B56δ-WT but not GFP-B56δ-S573A. Immunoblot analysis of the phosphoproteome in ARVM expressing GFP-B56δ-WT or GFP-B56δ-S573A with antibodies detecting (i) phospho-serine/threonine residues in distinct kinase substrate motifs or (ii) specific phosphorylated residues of functional importance in selected proteins revealed a comparable phosphorylation profile in the absence or presence of ISO stimulation. Conclusions In cardiomyocytes, βAR stimulation induces PKA-mediated phosphorylation of the PP2A regulatory subunit isoform B56δ at S573, which increases associated PP2A catalytic activity. This is likely to regulate the phosphorylation status of specific B56δ-PP2A substrates, which remain to be identified. PP2A subunit B56δ is phosphorylated on β-adrenergic stimulation of cardiomyocytes. Phosphorylation occurs at Ser573 and increases B56δ-PP2A catalytic activity. Response is mediated by the β1-adrenoceptor subtype and protein kinase A. Phosphorylated B56δ abundance is increased in pathological cardiac hypertrophy.
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Affiliation(s)
- Antonella Ranieri
- School of Cardiovascular Medicine and Sciences, King's College London British Heart Foundation Centre of Research Excellence, The Rayne Institute, St Thomas' Hospital, London, United Kingdom
| | - Elizabeth Kemp
- School of Cardiovascular Medicine and Sciences, King's College London British Heart Foundation Centre of Research Excellence, The Rayne Institute, St Thomas' Hospital, London, United Kingdom
| | - Joseph R Burgoyne
- School of Cardiovascular Medicine and Sciences, King's College London British Heart Foundation Centre of Research Excellence, The Rayne Institute, St Thomas' Hospital, London, United Kingdom
| | - Metin Avkiran
- School of Cardiovascular Medicine and Sciences, King's College London British Heart Foundation Centre of Research Excellence, The Rayne Institute, St Thomas' Hospital, London, United Kingdom.
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20
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Abstract
Cardiac and skeletal striated muscles are intricately designed machines responsible for muscle contraction. Coordination of the basic contractile unit, the sarcomere, and the complex cytoskeletal networks are critical for contractile activity. The sarcomere is comprised of precisely organized individual filament systems that include thin (actin), thick (myosin), titin, and nebulin. Connecting the sarcomere to other organelles (e.g., mitochondria and nucleus) and serving as the scaffold to maintain cellular integrity are the intermediate filaments. The costamere, on the other hand, tethers the sarcomere to the cell membrane. Unique structures like the intercalated disc in cardiac muscle and the myotendinous junction in skeletal muscle help synchronize and transmit force. Intense investigation has been done on many of the proteins that make up these cytoskeletal assemblies. Yet the details of their function and how they interconnect have just started to be elucidated. A vast number of human myopathies are contributed to mutations in muscle proteins; thus understanding their basic function provides a mechanistic understanding of muscle disorders. In this review, we highlight the components of striated muscle with respect to their interactions, signaling pathways, functions, and connections to disease. © 2017 American Physiological Society. Compr Physiol 7:891-944, 2017.
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Affiliation(s)
- Christine A Henderson
- Department of Cellular and Molecular Medicine, The University of Arizona, Tucson, Arizona, USA.,Sarver Molecular Cardiovascular Research Program, The University of Arizona, Tucson, Arizona, USA
| | - Christopher G Gomez
- Department of Cellular and Molecular Medicine, The University of Arizona, Tucson, Arizona, USA.,Sarver Molecular Cardiovascular Research Program, The University of Arizona, Tucson, Arizona, USA
| | - Stefanie M Novak
- Department of Cellular and Molecular Medicine, The University of Arizona, Tucson, Arizona, USA.,Sarver Molecular Cardiovascular Research Program, The University of Arizona, Tucson, Arizona, USA
| | - Lei Mi-Mi
- Department of Cellular and Molecular Medicine, The University of Arizona, Tucson, Arizona, USA.,Sarver Molecular Cardiovascular Research Program, The University of Arizona, Tucson, Arizona, USA
| | - Carol C Gregorio
- Department of Cellular and Molecular Medicine, The University of Arizona, Tucson, Arizona, USA.,Sarver Molecular Cardiovascular Research Program, The University of Arizona, Tucson, Arizona, USA
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21
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Ikenberg E, Karin I, Ertl-Wagner B, Abicht A, Bulst S, Krause S, Schoser B, Reilich P, Walter MC. Rare diagnosis of telethoninopathy (LGMD2G) in a Turkish patient. Neuromuscul Disord 2017; 27:856-860. [PMID: 28666572 DOI: 10.1016/j.nmd.2017.05.017] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2017] [Revised: 05/01/2017] [Accepted: 05/30/2017] [Indexed: 10/19/2022]
Abstract
Telethoninopathy is one of the rarest forms of Limb-girdle muscular dystrophy (LGMD). So far, only a small number of LGMD type 2 G (LGMD2G) patients have been described, mostly patients from Brazil. Here we present a 35-year-old female patient of Turkish ethnicity with LGMD2G due to a novel homozygous frame-shift mutation c.90_91del (p.Ser31Hisfs*11) in the telethonin gene, probably leading to truncated protein or nonsense mediated decay. Myalgia and walking on tiptoes were the first symptoms starting in early childhood, around age 22 proximal, later distal leg muscles became affected. Muscle biopsy showed a degenerative myopathy with lobulated fibers, creatine kinase levels were elevated to 1200 U/l. No cardiomyopathy has been detected but ventricular extrasystoles were treated with verapamil. Even though telethoninopathy represents a rare condition, testing for LGMD2G should be included into the diagnostic work-up of mild myopathies with early toe walking and distal and proximal involvement.
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Affiliation(s)
- Elena Ikenberg
- Friedrich-Baur-Institute, Dept. of Neurology, Ludwig-Maximilians-University of Munich, Munich, Germany
| | - Ivan Karin
- Friedrich-Baur-Institute, Dept. of Neurology, Ludwig-Maximilians-University of Munich, Munich, Germany
| | - Birgit Ertl-Wagner
- Dept. of Radiology, Ludwig-Maximilians-University of Munich, Munich, Germany
| | - Angela Abicht
- Friedrich-Baur-Institute, Dept. of Neurology, Ludwig-Maximilians-University of Munich, Munich, Germany; Medical Genetics Center - MGZ, Munich, Germany
| | | | - Sabine Krause
- Friedrich-Baur-Institute, Dept. of Neurology, Ludwig-Maximilians-University of Munich, Munich, Germany
| | - Benedikt Schoser
- Friedrich-Baur-Institute, Dept. of Neurology, Ludwig-Maximilians-University of Munich, Munich, Germany
| | - Peter Reilich
- Friedrich-Baur-Institute, Dept. of Neurology, Ludwig-Maximilians-University of Munich, Munich, Germany
| | - Maggie C Walter
- Friedrich-Baur-Institute, Dept. of Neurology, Ludwig-Maximilians-University of Munich, Munich, Germany.
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22
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Weeks KL, Ranieri A, Karaś A, Bernardo BC, Ashcroft AS, Molenaar C, McMullen JR, Avkiran M. β-Adrenergic Stimulation Induces Histone Deacetylase 5 (HDAC5) Nuclear Accumulation in Cardiomyocytes by B55α-PP2A-Mediated Dephosphorylation. J Am Heart Assoc 2017; 6:JAHA.116.004861. [PMID: 28343149 PMCID: PMC5533001 DOI: 10.1161/jaha.116.004861] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Background Class IIa histone deacetylase (HDAC) isoforms such as HDAC5 are critical signal‐responsive repressors of maladaptive cardiomyocyte hypertrophy, through nuclear interactions with transcription factors including myocyte enhancer factor‐2. β‐Adrenoceptor (β‐AR) stimulation, a signal of fundamental importance in regulating cardiac function, has been proposed to induce both phosphorylation‐independent nuclear export and phosphorylation‐dependent nuclear accumulation of cardiomyocyte HDAC5. The relative importance of phosphorylation at Ser259/Ser498 versus Ser279 in HDAC5 regulation is also controversial. We aimed to determine the impact of β‐AR stimulation on the phosphorylation, localization, and function of cardiomyocyte HDAC5 and delineate underlying molecular mechanisms. Methods and Results A novel 3‐dimensional confocal microscopy method that objectively quantifies the whole‐cell nuclear/cytoplasmic distribution of green fluorescent protein tagged HDAC5 revealed the β‐AR agonist isoproterenol to induce β1‐AR‐mediated and protein kinase A‐dependent HDAC5 nuclear accumulation in adult rat cardiomyocytes, which was accompanied by dephosphorylation at Ser259/279/498. Mutation of Ser259/Ser498 to Ala promoted HDAC5 nuclear accumulation and myocyte enhancer factor‐2 inhibition, whereas Ser279 ablation had no such effect and did not block isoproterenol‐induced nuclear accumulation. Inhibition of the Ser/Thr phosphatase PP2A blocked isoproterenol‐induced HDAC5 dephosphorylation. Co‐immunoprecipitation revealed a specific interaction of HDAC5 with the PP2A targeting subunit B55α, as well as catalytic and scaffolding subunits, which increased >3‐fold with isoproterenol. Knockdown of B55α in neonatal cardiomyocytes attenuated isoproterenol‐induced HDAC5 dephosphorylation. Conclusions β‐AR stimulation induces HDAC5 nuclear accumulation in cardiomyocytes by a mechanism that is protein kinase A‐dependent but requires B55α‐PP2A‐mediated dephosphorylation of Ser259/Ser498 rather than protein kinase A‐mediated phosphorylation of Ser279.
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Affiliation(s)
- Kate L Weeks
- Cardiovascular Division, King's College London British Heart Foundation Centre of Research Excellence, The Rayne Institute, St Thomas' Hospital, London, United Kingdom.,Baker Heart and Diabetes Institute, Melbourne, Australia
| | - Antonella Ranieri
- Cardiovascular Division, King's College London British Heart Foundation Centre of Research Excellence, The Rayne Institute, St Thomas' Hospital, London, United Kingdom
| | - Agnieszka Karaś
- Cardiovascular Division, King's College London British Heart Foundation Centre of Research Excellence, The Rayne Institute, St Thomas' Hospital, London, United Kingdom
| | | | - Alexandra S Ashcroft
- Cardiovascular Division, King's College London British Heart Foundation Centre of Research Excellence, The Rayne Institute, St Thomas' Hospital, London, United Kingdom
| | - Chris Molenaar
- Cardiovascular Division, King's College London British Heart Foundation Centre of Research Excellence, The Rayne Institute, St Thomas' Hospital, London, United Kingdom
| | | | - Metin Avkiran
- Cardiovascular Division, King's College London British Heart Foundation Centre of Research Excellence, The Rayne Institute, St Thomas' Hospital, London, United Kingdom
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23
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Wood BM, Bossuyt J. Emergency Spatiotemporal Shift: The Response of Protein Kinase D to Stress Signals in the Cardiovascular System. Front Pharmacol 2017; 8:9. [PMID: 28174535 PMCID: PMC5258689 DOI: 10.3389/fphar.2017.00009] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2016] [Accepted: 01/04/2017] [Indexed: 12/12/2022] Open
Abstract
Protein Kinase D isoforms (PKD 1-3) are key mediators of neurohormonal, oxidative, and metabolic stress signals. PKDs impact a wide variety of signaling pathways and cellular functions including actin dynamics, vesicle trafficking, cell motility, survival, contractility, energy substrate utilization, and gene transcription. PKD activity is also increasingly linked to cancer, immune regulation, pain modulation, memory, angiogenesis, and cardiovascular disease. This increasing complexity and diversity of PKD function, highlights the importance of tight spatiotemporal control of the kinase via protein–protein interactions, post-translational modifications or targeting via scaffolding proteins. In this review, we focus on the spatiotemporal regulation and effects of PKD signaling in response to neurohormonal, oxidant and metabolic signals that have implications for myocardial disease. Precise targeting of these mechanisms will be crucial in the design of PKD-based therapeutic strategies.
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Affiliation(s)
- Brent M Wood
- Department of Pharmacology, University of California, Davis, Davis CA, USA
| | - Julie Bossuyt
- Department of Pharmacology, University of California, Davis, Davis CA, USA
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24
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Gautel M, Djinović-Carugo K. The sarcomeric cytoskeleton: from molecules to motion. ACTA ACUST UNITED AC 2016; 219:135-45. [PMID: 26792323 DOI: 10.1242/jeb.124941] [Citation(s) in RCA: 143] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Highly ordered organisation of striated muscle is the prerequisite for the fast and unidirectional development of force and motion during heart and skeletal muscle contraction. A group of proteins, summarised as the sarcomeric cytoskeleton, is essential for the ordered assembly of actin and myosin filaments into sarcomeres, by combining architectural, mechanical and signalling functions. This review discusses recent cell biological, biophysical and structural insight into the regulated assembly of sarcomeric cytoskeleton proteins and their roles in dissipating mechanical forces in order to maintain sarcomere integrity during passive extension and active contraction. α-Actinin crosslinks in the Z-disk show a pivot-and-rod structure that anchors both titin and actin filaments. In contrast, the myosin crosslinks formed by myomesin in the M-band are of a ball-and-spring type and may be crucial in providing stable yet elastic connections during active contractions, especially eccentric exercise.
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Affiliation(s)
- Mathias Gautel
- King's College London BHF Centre of Research Excellence, Randall Division for Cell and Molecular Biophysics, and Cardiovascular Division, New Hunt's House, London SE1 1UL, UK
| | - Kristina Djinović-Carugo
- Department of Structural and Computational Biology, Max F. Perutz Laboratories, University of Vienna, Campus Vienna Biocenter 5, Vienna A-1030, Austria Department of Biochemistry, Faculty of Chemistry and Chemical Technology, University of Ljubljana, Aškerčeva 5, Ljubljana 1000, Slovenia
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25
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Qiu W, Steinberg SF. Phos-tag SDS-PAGE resolves agonist- and isoform-specific activation patterns for PKD2 and PKD3 in cardiomyocytes and cardiac fibroblasts. J Mol Cell Cardiol 2016; 99:14-22. [PMID: 27515283 DOI: 10.1016/j.yjmcc.2016.08.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Revised: 08/05/2016] [Accepted: 08/06/2016] [Indexed: 01/16/2023]
Abstract
Protein kinase D (PKD) consists of a family of three structurally related enzymes that are co-expressed in the heart and have important roles in many biological responses. PKD1 is activated by pro-hypertrophic stimuli and has been implicated in adverse cardiac remodeling. Efforts to define the cardiac actions of PKD2 and PKD3 have been less successful at least in part because conventional methods provide a general screen for PKD activation but are poorly suited to resolve activation patterns for PKD2 or PKD3. This study uses Phos-tag SDS-PAGE, a method that exaggerates phosphorylation-dependent mobility shifts, to overcome this technical limitation. Phos-tag SDS-PAGE resolves PKD1 as distinct molecular species (indicative of pools of enzyme with distinct phosphorylation profiles) in unstimulated cardiac fibroblasts and cardiomyocytes; as a result, attempts to track PKD1 mobility shifts that result from agonist activation were only moderately successful. In contrast, PKD2 and PKD3 are recovered from resting cardiac fibroblasts and cardiomyocytes as single molecular species; both enzymes display robust mobility shifts in Phos-tag SDS-PAGE in response to treatment with sphingosine-1-phosphate, thrombin, PDGF, or H2O2. Studies with GF109203X implicate protein kinase C activity in the stimulus-dependent pathways that activate PKD2/PKD3 in both cardiac fibroblasts and cardiomyocytes. Studies with C3 toxin identify a novel role for Rho in the sphingosine-1-phosphate and thrombin receptor-dependent pathways that lead to the phosphorylation of PKD2/3 and the downstream substrate CREB in cardiomyocytes. In conclusion, Phos-tag SDS-PAGE provides a general screen for stimulus-specific changes in PKD2 and PKD3 phosphorylation and exposes a novel role for these enzymes in specific stress-dependent pathways that influence cardiac remodeling.
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Affiliation(s)
- Weihua Qiu
- Department of Pharmacology, Columbia University, New York, NY 10032, United States
| | - Susan F Steinberg
- Department of Pharmacology, Columbia University, New York, NY 10032, United States.
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26
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Puhl SL, Weeks KL, Ranieri A, Avkiran M. Assessing structural and functional responses of murine hearts to acute and sustained β-adrenergic stimulation in vivo. J Pharmacol Toxicol Methods 2016; 79:60-71. [PMID: 26836145 PMCID: PMC4840275 DOI: 10.1016/j.vascn.2016.01.007] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2015] [Revised: 01/28/2016] [Accepted: 01/29/2016] [Indexed: 11/18/2022]
Abstract
Introduction Given the importance of β-adrenoceptor signalling in regulating cardiac structure and function, robust protocols are required to assess potential alterations in such regulation in murine models in vivo. Methods Echocardiography was performed in naïve and stressed (isoprenaline; 30 μg/g/day s.c. for up to 14 days) mice, in the absence or presence of acute β-adrenergic stimulation (dobutamine 0.75 μg/g, i.p.). Controls received saline infusion and/or injection. Hearts were additionally analysed gravimetrically, histologically and biochemically. Results In naïve mice, acute β-adrenoceptor stimulation with dobutamine increased heart rate, left ventricular (LV) fractional shortening (LVFS), ejection fraction (LVEF) and wall thickness and decreased LV diameter (p < 0.05). In stressed mice, dobutamine failed to induce further inotropic and chronotropic responses. Furthermore, following dobutamine injection, these mice exhibited lower LVEF and LVFS at identical heart rates, relative to corresponding controls. Sustained isoprenaline infusion induced LV hypertrophy (increased heart weight, heart weight/body weight ratio, heart weight/tibia length ratio and LV wall thickness (p < 0.05)) by 3 days, with little further change at 14 days. In contrast, increases in LVEF and LVFS were seen only at 14 days (p < 0.05). Discussion We describe protocols for and illustrative data from the assessment of murine cardiac responses to acute and sustained β-adrenergic stimulation in vivo, which would be of value in determining the impact of genetic or pharmacological interventions on such responses. Additionally, our data indicate that acute dobutamine stimulation unmasks early signs of LV dysfunction in the remodelled heart, even at a stage when basal function is enhanced.
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Affiliation(s)
- Sarah-Lena Puhl
- Cardiovascular Division, King's College London British Heart Foundation Centre of Research Excellence, The Rayne Institute, St Thomas' Hospital, London SE1 7EH, United Kingdom.
| | - Kate L Weeks
- Cardiovascular Division, King's College London British Heart Foundation Centre of Research Excellence, The Rayne Institute, St Thomas' Hospital, London SE1 7EH, United Kingdom.
| | - Antonella Ranieri
- Cardiovascular Division, King's College London British Heart Foundation Centre of Research Excellence, The Rayne Institute, St Thomas' Hospital, London SE1 7EH, United Kingdom.
| | - Metin Avkiran
- Cardiovascular Division, King's College London British Heart Foundation Centre of Research Excellence, The Rayne Institute, St Thomas' Hospital, London SE1 7EH, United Kingdom.
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27
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White J, Barro MV, Makarenkova HP, Sanger JW, Sanger JM. Localization of sarcomeric proteins during myofibril assembly in cultured mouse primary skeletal myotubes. Anat Rec (Hoboken) 2015; 297:1571-84. [PMID: 25125171 DOI: 10.1002/ar.22981] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2014] [Accepted: 05/03/2014] [Indexed: 01/02/2023]
Abstract
It is important to understand how muscle forms normally in order to understand muscle diseases that result in abnormal muscle formation. Although the structure of myofibrils is well understood, the process through which the myofibril components form organized contractile units is not clear. Based on the staining of muscle proteins in avian embryonic cardiomyocytes, we previously proposed that myofibrils formation occurred in steps that began with premyofibrils followed by nascent myofibrils and ending with mature myofibrils. The purpose of this study was to determine whether the premyofibril model of myofibrillogenesis developed from studies developed from studies in avian cardiomyocytes was supported by our current studies of myofibril assembly in mouse skeletal muscle. Emphasis was on establishing how the key sarcomeric proteins, F-actin, nonmuscle myosin II, muscle myosin II, and α-actinin were organized in the three stages of myofibril assembly. The results also test previous reports that nonmuscle myosins II A and B are components of the Z-bands of mature myofibrils, data that are inconsistent with the premyofibril model. We have also determined that in mouse muscle cells, telethonin is a late assembling protein that is present only in the Z-bands of mature myofibrils. This result of using specific telethonin antibodies supports the approach of using YFP-tagged proteins to determine where and when these YFP-sarcomeric fusion proteins are localized. The data presented in this study on cultures of primary mouse skeletal myocytes are consistent with the premyofibril model of myofibrillogenesis previously proposed for both avian cardiac and skeletal muscle cells.
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Affiliation(s)
- Jennifer White
- Department of Medicine, SUNY Upstate Medical University, Syracuse, New York
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28
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Martino TA, Young ME. Influence of the Cardiomyocyte Circadian Clock on Cardiac Physiology and Pathophysiology. J Biol Rhythms 2015; 30:183-205. [DOI: 10.1177/0748730415575246] [Citation(s) in RCA: 82] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Cardiac function and dysfunction exhibit striking time-of-day-dependent oscillations. Disturbances in both daily rhythms and sleep are associated with increased risk of heart disease, adverse cardiovascular events, and worsening outcomes. For example, the importance of maintaining normal daily rhythms is highlighted by epidemiologic observations that night shift workers present with increased incidence of cardiovascular disease. Rhythmicity in cardiac processes is mediated by a complex interaction between extracardiac (e.g., behaviors and associated neural and humoral fluctuations) and intracardiac influences. Over the course of the day, the intrinsic properties of the myocardium vary at the levels of gene and protein expression, metabolism, responsiveness to extracellular stimuli/stresses, and ion homeostasis, all of which affect contractility (e.g., heart rate and force generation). Over the past decade, the circadian clock within the cardiomyocyte has emerged as an essential mechanism responsible for modulating the intrinsic properties of the heart. Moreover, the critical role of this mechanism is underscored by reports that disruption, through genetic manipulation, results in development of cardiac disease and premature mortality in mice. These findings, in combination with reports that numerous cardiovascular risk factors (e.g., diet, diabetes, aging) distinctly affect the clock in the heart, have led to the hypothesis that aberrant regulation of this mechanism contributes to the etiology of cardiac dysfunction and disease. Here, we provide a comprehensive review on current knowledge regarding known roles of the heart clock and discuss the potential for using these insights for the future development of innovative strategies for the treatment of cardiovascular disease.
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Affiliation(s)
- Tami A. Martino
- Cardiovascular Research Group, Department of Biomedical Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Martin E. Young
- Division of Cardiovascular Diseases, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, USA
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29
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Bogomolovas J, Gasch A, Simkovic F, Rigden DJ, Labeit S, Mayans O. Titin kinase is an inactive pseudokinase scaffold that supports MuRF1 recruitment to the sarcomeric M-line. Open Biol 2015; 4:140041. [PMID: 24850911 PMCID: PMC4042850 DOI: 10.1098/rsob.140041] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Striated muscle tissues undergo adaptive remodelling in response to mechanical load. This process involves the myofilament titin and, specifically, its kinase domain (TK; titin kinase) that translates mechanical signals into regulatory pathways of gene expression in the myofibril. TK mechanosensing appears mediated by a C-terminal regulatory tail (CRD) that sterically inhibits its active site. Allegedly, stretch-induced unfolding of this tail during muscle function releases TK inhibition and leads to its catalytic activation. However, the cellular pathway of TK is poorly understood and substrates proposed to date remain controversial. TK's best-established substrate is Tcap, a small structural protein of the Z-disc believed to link TK to myofibrillogenesis. Here, we show that TK is a pseudokinase with undetectable levels of catalysis and, therefore, that Tcap is not its substrate. Inactivity is the result of two atypical residues in TK's active site, M34 and E147, that do not appear compatible with canonical kinase patterns. While not mediating stretch-dependent phospho-transfers, TK binds the E3 ubiquitin ligase MuRF1 that promotes sarcomeric ubiquitination in a stress-induced manner. Given previous evidence of MuRF2 interaction, we propose that the cellular role of TK is to act as a conformationally regulated scaffold that functionally couples the ubiquitin ligases MuRF1 and MuRF2, thereby coordinating muscle-specific ubiquitination pathways and myofibril trophicity. Finally, we suggest that an evolutionary dichotomy of kinases/pseudokinases has occurred in TK-like kinases, where invertebrate members are active enzymes but vertebrate counterparts perform their signalling function as pseudokinase scaffolds.
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Affiliation(s)
- Julijus Bogomolovas
- Department of Integrative Pathophysiology, Medical Faculty Mannheim, University of Heidelberg, Mannheim 68167, Germany Institute of Integrative Biology, Biosciences Building, University of Liverpool, Crown St., Liverpool L69 7ZB, UK
| | - Alexander Gasch
- Department of Integrative Pathophysiology, Medical Faculty Mannheim, University of Heidelberg, Mannheim 68167, Germany
| | - Felix Simkovic
- Institute of Integrative Biology, Biosciences Building, University of Liverpool, Crown St., Liverpool L69 7ZB, UK
| | - Daniel J Rigden
- Institute of Integrative Biology, Biosciences Building, University of Liverpool, Crown St., Liverpool L69 7ZB, UK
| | - Siegfried Labeit
- Department of Integrative Pathophysiology, Medical Faculty Mannheim, University of Heidelberg, Mannheim 68167, Germany
| | - Olga Mayans
- Institute of Integrative Biology, Biosciences Building, University of Liverpool, Crown St., Liverpool L69 7ZB, UK
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30
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Barresi R, Morris C, Hudson J, Curtis E, Pickthall C, Bushby K, Davies NP, Straub V. Conserved expression of truncated telethonin in a patient with limb-girdle muscular dystrophy 2G. Neuromuscul Disord 2014; 25:349-52. [PMID: 25724973 DOI: 10.1016/j.nmd.2014.12.006] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2014] [Revised: 12/04/2014] [Accepted: 12/11/2014] [Indexed: 11/19/2022]
Abstract
Limb-girdle muscular dystrophy 2G is caused by mutations in the TCAP gene that encodes for telethonin. Here we describe a 49 year-old male patient of Indian descent presenting a classical LGMD phenotype. He had normal motor milestones but became noticeably slower in his early teens and was wheelchair bound by age 44. The muscle biopsy showed myopathic features and absence of labeling with an antibody to the C-terminal portion of telethonin. Sequence analysis of the TCAP gene revealed a novel homozygous mutation in exon 2, predicted to generate a truncated protein of 81 amino acids. Interestingly, an antibody for the full-length protein showed labeling on sections and a single band of ~10 kDa on Western blot. The truncated protein co-localized with filamin C at the Z-line. Our findings indicate that mutant telethonin can be incorporated into the sarcomere and that other LGMD2G patients with retention of telethonin expression may exist.
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Affiliation(s)
- Rita Barresi
- Rare Diseases Advisory Group Service for Neuromuscular Diseases, Muscle Immunoanalysis Unit, Dental Hospital, Richardson Road, Newcastle upon Tyne, UK; The JW Muscular Dystrophy Research Centre and MRC Centre for Neuromuscular Diseases, Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne, UK.
| | - Charlotte Morris
- Rare Diseases Advisory Group Service for Neuromuscular Diseases, Muscle Immunoanalysis Unit, Dental Hospital, Richardson Road, Newcastle upon Tyne, UK
| | - Judith Hudson
- The JW Muscular Dystrophy Research Centre and MRC Centre for Neuromuscular Diseases, Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne, UK
| | - Elizabeth Curtis
- Department of Cellular Pathology, University Hospital of Birmingham NHS Foundation Trust, Birmingham, UK
| | - Clare Pickthall
- The JW Muscular Dystrophy Research Centre and MRC Centre for Neuromuscular Diseases, Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne, UK
| | - Kate Bushby
- The JW Muscular Dystrophy Research Centre and MRC Centre for Neuromuscular Diseases, Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne, UK
| | - Nicholas P Davies
- Department of Neurology, University Hospital of Birmingham NHS Foundation Trust, Birmingham, UK
| | - Volker Straub
- The JW Muscular Dystrophy Research Centre and MRC Centre for Neuromuscular Diseases, Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne, UK
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31
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Ojima K, Ono Y, Hata S, Noguchi S, Nishino I, Sorimachi H. Muscle-specific calpain-3 is phosphorylated in its unique insertion region for enrichment in a myofibril fraction. Genes Cells 2014; 19:830-41. [DOI: 10.1111/gtc.12181] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2014] [Accepted: 08/20/2014] [Indexed: 12/31/2022]
Affiliation(s)
- Koichi Ojima
- Animal Products Research Division; NARO Institute of Livestock and Grassland Science; 2 Ikenodai Tsukuba Ibaraki 305-0901 Japan
- Calpain Project; Department of Advanced Science for Biomolecules; Tokyo Metropolitan Institute of Medical Science; 2-1-6 Kamikitazawa Setagaya-ku Tokyo 156-8506 Japan
| | - Yasuko Ono
- Calpain Project; Department of Advanced Science for Biomolecules; Tokyo Metropolitan Institute of Medical Science; 2-1-6 Kamikitazawa Setagaya-ku Tokyo 156-8506 Japan
| | - Shoji Hata
- Calpain Project; Department of Advanced Science for Biomolecules; Tokyo Metropolitan Institute of Medical Science; 2-1-6 Kamikitazawa Setagaya-ku Tokyo 156-8506 Japan
| | - Satoru Noguchi
- Department of Neuromuscular Research; National Institute of Neuroscience; National Center of Neurology and Psychiatry; 4-1-1 Ogawa-Higashi Kodaira Tokyo 187-8502 Japan
| | - Ichizo Nishino
- Department of Neuromuscular Research; National Institute of Neuroscience; National Center of Neurology and Psychiatry; 4-1-1 Ogawa-Higashi Kodaira Tokyo 187-8502 Japan
| | - Hiroyuki Sorimachi
- Calpain Project; Department of Advanced Science for Biomolecules; Tokyo Metropolitan Institute of Medical Science; 2-1-6 Kamikitazawa Setagaya-ku Tokyo 156-8506 Japan
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Circadian regulation of myocardial sarcomeric Titin-cap (Tcap, telethonin): identification of cardiac clock-controlled genes using open access bioinformatics data. PLoS One 2014; 9:e104907. [PMID: 25121604 PMCID: PMC4133362 DOI: 10.1371/journal.pone.0104907] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2014] [Accepted: 07/17/2014] [Indexed: 12/26/2022] Open
Abstract
Circadian rhythms are important for healthy cardiovascular physiology and are regulated at the molecular level by a circadian clock mechanism. We and others previously demonstrated that 9–13% of the cardiac transcriptome is rhythmic over 24 h daily cycles; the heart is genetically a different organ day versus night. However, which rhythmic mRNAs are regulated by the circadian mechanism is not known. Here, we used open access bioinformatics databases to identify 94 transcripts with expression profiles characteristic of CLOCK and BMAL1 targeted genes, using the CircaDB website and JTK_Cycle. Moreover, 22 were highly expressed in the heart as determined by the BioGPS website. Furthermore, 5 heart-enriched genes had human/mouse conserved CLOCK:BMAL1 promoter binding sites (E-boxes), as determined by UCSC table browser, circadian mammalian promoter/enhancer database PEDB, and the European Bioinformatics Institute alignment tool (EMBOSS). Lastly, we validated findings by demonstrating that Titin cap (Tcap, telethonin) was targeted by transcriptional activators CLOCK and BMAL1 by showing 1) Tcap mRNA and TCAP protein had a diurnal rhythm in murine heart; 2) cardiac Tcap mRNA was rhythmic in animals kept in constant darkness; 3) Tcap and control Per2 mRNA expression and cyclic amplitude were blunted in ClockΔ19/Δ19 hearts; 4) BMAL1 bound to the Tcap promoter by ChIP assay; 5) BMAL1 bound to Tcap promoter E-boxes by biotinylated oligonucleotide assay; and 6) CLOCK and BMAL1 induced tcap expression by luciferase reporter assay. Thus this study identifies circadian regulated genes in silico, with validation of Tcap, a critical regulator of cardiac Z-disc sarcomeric structure and function.
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Abstract
The giant protein titin forms a unique filament network in cardiomyocytes, which engages in both mechanical and signaling functions of the heart. TTN, which encodes titin, is also a major human disease gene. In this review, we cover the roles of cardiac titin in normal and failing hearts, with a special emphasis on the contribution of titin to diastolic stiffness. We provide an update on disease-associated titin mutations in cardiac and skeletal muscles and summarize what is known about the impact of protein-protein interactions on titin properties and functions. We discuss the importance of titin-isoform shifts and titin phosphorylation, as well as titin modifications related to oxidative stress, in adjusting the diastolic stiffness of the healthy and the failing heart. Along the way we distinguish among titin alterations in systolic and in diastolic heart failure and ponder the evidence for titin stiffness as a potential target for pharmacological intervention in heart disease.
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Affiliation(s)
- Wolfgang A Linke
- From the Department of Cardiovascular Physiology, Ruhr University Bochum, Bochum, Germany
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