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Kodippili K, Hakim CH, Burke MJ, Yue Y, Teixeira JA, Zhang K, Yao G, Babu GJ, Herzog RW, Duan D. SERCA2a overexpression improves muscle function in a canine Duchenne muscular dystrophy model. Mol Ther Methods Clin Dev 2024; 32:101268. [PMID: 38911286 PMCID: PMC11190715 DOI: 10.1016/j.omtm.2024.101268] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2024] [Accepted: 05/16/2024] [Indexed: 06/25/2024]
Abstract
Excessive cytosolic calcium accumulation contributes to muscle degeneration in Duchenne muscular dystrophy (DMD). Sarco/endoplasmic reticulum calcium ATPase (SERCA) is a sarcoplasmic reticulum (SR) calcium pump that actively transports calcium from the cytosol into the SR. We previously showed that adeno-associated virus (AAV)-mediated SERCA2a therapy reduced cytosolic calcium overload and improved muscle and heart function in the murine DMD model. Here, we tested whether AAV SERCA2a therapy could ameliorate muscle disease in the canine DMD model. 7.83 × 1013 vector genome particles of the AAV vector were injected into the extensor carpi ulnaris (ECU) muscles of four juvenile affected dogs. Contralateral ECU muscles received excipient. Three months later, we observed widespread transgene expression and significantly increased SERCA2a levels in the AAV-injected muscles. Treatment improved SR calcium uptake, significantly reduced calpain activity, significantly improved contractile kinetics, and significantly enhanced resistance to eccentric contraction-induced force loss. Nonetheless, muscle histology was not improved. To evaluate the safety of AAV SERCA2a therapy, we delivered the vector to the ECU muscle of adult normal dogs. We achieved strong transgene expression without altering muscle histology and function. Our results suggest that AAV SERCA2a therapy has the potential to improve muscle performance in a dystrophic large mammal.
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Affiliation(s)
- Kasun Kodippili
- Department of Molecular Microbiology and Immunology, School of Medicine, The University of Missouri, Columbia, MO 65212, USA
| | - Chady H. Hakim
- Department of Molecular Microbiology and Immunology, School of Medicine, The University of Missouri, Columbia, MO 65212, USA
| | - Matthew J. Burke
- Department of Molecular Microbiology and Immunology, School of Medicine, The University of Missouri, Columbia, MO 65212, USA
| | - Yongping Yue
- Department of Molecular Microbiology and Immunology, School of Medicine, The University of Missouri, Columbia, MO 65212, USA
| | - James A. Teixeira
- Department of Molecular Microbiology and Immunology, School of Medicine, The University of Missouri, Columbia, MO 65212, USA
| | - Keqing Zhang
- Department of Molecular Microbiology and Immunology, School of Medicine, The University of Missouri, Columbia, MO 65212, USA
| | - Gang Yao
- Department of Chemical and Biomedical Engineering, College of Engineering, The University of Missouri, Columbia, MO 65212, USA
| | - Gopal J. Babu
- Department of Cell Biology and Molecular Medicine, Rutgers New Jersey Medical School, Newark, NJ 07103, USA
| | - Roland W. Herzog
- Herman B Wells Center for Pediatric Research, Indiana University, Indianapolis, IN 46202, USA
| | - Dongsheng Duan
- Department of Molecular Microbiology and Immunology, School of Medicine, The University of Missouri, Columbia, MO 65212, USA
- Department of Chemical and Biomedical Engineering, College of Engineering, The University of Missouri, Columbia, MO 65212, USA
- Department of Neurology, School of Medicine, The University of Missouri, Columbia, MO 65212, USA
- Department of Biomedical Sciences, College of Veterinary Medicine, The University of Missouri, Columbia, MO 65212, USA
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2
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Cizauskas HE, Burnham HV, Panni A, Pena A, Alvarez-Arce A, Davis MT, Araujo KN, Delligatti C, Edassery S, Kirk JA, Arora R, Barefield DY. Proteolytic degradation of atrial sarcomere proteins underlies contractile defects in atrial fibrillation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.05.565691. [PMID: 37961455 PMCID: PMC10635151 DOI: 10.1101/2023.11.05.565691] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
Aims Atrial fibrillation (AFib) is the most common cardiac rhythm disturbance. Treatment of AFib involves restoration of the atrial electrical rhythm. Following rhythm restoration, a period of depressed mechanical function known as atrial stunning occurs that involves decreased blood flow velocity and reduced atrial contractility. This suggests that defects in contractility occur in AFib and are revealed upon restoration of rhythm. The aim of this project is to define the contractile remodeling that occurs in AFib. Methods and Results To assess contractile function, we used a canine atrial tachypacing model of induced AFib. Mass spectrometry analysis showed dysregulation of contractile proteins in samples from AFib compared to sinus rhythm atria. Atrial cardiomyocytes showed reduced force of contraction in skinned single cardiomyocyte calcium-force studies. There were no significant differences in myosin heavy chain isoform expression. Resting tension is decreased in the AFib samples correlating with reduced full-length titin in the sarcomere. We measured degradation of other myofilament proteins including cMyBP-C, actinin, and cTnI, showing significant degradation in the AFib samples compared to sinus rhythm atria. Many of the protein degradation products appeared as discrete cleavage products that are generated by calpain proteolysis. We assessed calpain activity and found it to be significantly increased. Skinned cardiomyocytes from AFib atria showed decreased troponin I phosphorylation, consistent with the increased calcium sensitivity that was found within these cardiomyocytes. Conclusions With these results it can be concluded that AFib causes alterations in contraction that can be explained by both molecular changes occurring in myofilament proteins and overall myofilament protein degradation. These results provide an understanding of the contractile remodeling that occurs in AFib and provides insight into the molecular explanation for atrial stunning and the increased risk of atrial thrombus and stroke in AFib.
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The Mechanisms of Thin Filament Assembly and Length Regulation in Muscles. Int J Mol Sci 2022; 23:ijms23105306. [PMID: 35628117 PMCID: PMC9140763 DOI: 10.3390/ijms23105306] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Revised: 05/05/2022] [Accepted: 05/06/2022] [Indexed: 02/01/2023] Open
Abstract
The actin containing tropomyosin and troponin decorated thin filaments form one of the crucial components of the contractile apparatus in muscles. The thin filaments are organized into densely packed lattices interdigitated with myosin-based thick filaments. The crossbridge interactions between these myofilaments drive muscle contraction, and the degree of myofilament overlap is a key factor of contractile force determination. As such, the optimal length of the thin filaments is critical for efficient activity, therefore, this parameter is precisely controlled according to the workload of a given muscle. Thin filament length is thought to be regulated by two major, but only partially understood mechanisms: it is set by (i) factors that mediate the assembly of filaments from monomers and catalyze their elongation, and (ii) by factors that specify their length and uniformity. Mutations affecting these factors can alter the length of thin filaments, and in human cases, many of them are linked to debilitating diseases such as nemaline myopathy and dilated cardiomyopathy.
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4
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Kolegova ES, Kakurina GV, Shashova EE, Yunusova NV, Spirina LV, Sidenko EA, Kostromitskiy DN, Dobrodeev AY, Kondakova IV. Relationship of intracellular proteolysis with CAP1 and cofilin1 in non-small-cell lung cancer. J Biosci 2021. [DOI: 10.1007/s12038-021-00177-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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5
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Wang S, Raza SHA, Mei C, Zhu K, Garcia M, Schreurs NM, Liang C, Yang X, Zan L. Transcriptome profiling reveals differential expression of genes potentially involved in muscle and adipose tissue development of cattle. ELECTRON J BIOTECHN 2020. [DOI: 10.1016/j.ejbt.2020.09.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
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6
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Under construction: The dynamic assembly, maintenance, and degradation of the cardiac sarcomere. J Mol Cell Cardiol 2020; 148:89-102. [PMID: 32920010 DOI: 10.1016/j.yjmcc.2020.08.018] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Revised: 08/20/2020] [Accepted: 08/22/2020] [Indexed: 12/11/2022]
Abstract
The sarcomere is the basic contractile unit of striated muscle and is a highly ordered protein complex with the actin and myosin filaments at its core. Assembling the sarcomere constituents into this organized structure in development, and with muscle growth as new sarcomeres are built, is a complex process coordinated by numerous factors. Once assembled, the sarcomere requires constant maintenance as its continuous contraction is accompanied by elevated mechanical, thermal, and oxidative stress, which predispose proteins to misfolding and toxic aggregation. To prevent protein misfolding and maintain sarcomere integrity, the sarcomere is monitored by an assortment of protein quality control (PQC) mechanisms. The need for effective PQC is heightened in cardiomyocytes which are terminally differentiated and must survive for many years while preserving optimal mechanical output. To prevent toxic protein aggregation, molecular chaperones stabilize denatured sarcomere proteins and promote their refolding. However, when old and misfolded proteins cannot be salvaged by chaperones, they must be recycled via degradation pathways: the calpain and ubiquitin-proteasome systems, which operate under basal conditions, and the stress-responsive autophagy-lysosome pathway. Mutations to and deficiency of the molecular chaperones and associated factors charged with sarcomere maintenance commonly lead to sarcomere structural disarray and the progression of heart disease, highlighting the necessity of effective sarcomere PQC for maintaining cardiac function. This review focuses on the dynamic regulation of assembly and turnover at the sarcomere with an emphasis on the chaperones involved in these processes and describes the alterations to chaperones - through mutations and deficient expression - implicated in disease progression to heart failure.
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7
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Kumari R, Jiu Y, Carman PJ, Tojkander S, Kogan K, Varjosalo M, Gunning PW, Dominguez R, Lappalainen P. Tropomodulins Control the Balance between Protrusive and Contractile Structures by Stabilizing Actin-Tropomyosin Filaments. Curr Biol 2020; 30:767-778.e5. [PMID: 32037094 DOI: 10.1016/j.cub.2019.12.049] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2019] [Revised: 11/06/2019] [Accepted: 12/16/2019] [Indexed: 02/08/2023]
Abstract
Eukaryotic cells have diverse protrusive and contractile actin filament structures, which compete with one another for a limited pool of actin monomers. Numerous actin-binding proteins regulate the dynamics of actin structures, including tropomodulins (Tmods), which cap the pointed end of actin filaments. In striated muscles, Tmods prevent actin filaments from overgrowing, whereas in non-muscle cells, their function has remained elusive. Here, we identify two Tmod isoforms, Tmod1 and Tmod3, as key components of contractile stress fibers in non-muscle cells. Individually, Tmod1 and Tmod3 can compensate for one another, but their simultaneous depletion results in disassembly of actin-tropomyosin filaments, loss of force-generating stress fibers, and severe defects in cell morphology. Knockout-rescue experiments reveal that Tmod's interaction with tropomyosin is essential for its role in the stabilization of actin-tropomyosin filaments in cells. Thus, in contrast to their role in muscle myofibrils, in non-muscle cells, Tmods bind actin-tropomyosin filaments to protect them from depolymerizing, not elongating. Furthermore, loss of Tmods shifts the balance from linear actin-tropomyosin filaments to Arp2/3 complex-nucleated branched networks, and this phenotype can be partially rescued by inhibiting the Arp2/3 complex. Collectively, the data reveal that Tmods are essential for the maintenance of contractile actomyosin bundles and that Tmod-dependent capping of actin-tropomyosin filaments is critical for the regulation of actin homeostasis in non-muscle cells.
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Affiliation(s)
- Reena Kumari
- HiLIFE Institute of Biotechnology, University of Helsinki, PO Box 56, 00014 Helsinki, Finland
| | - Yaming Jiu
- HiLIFE Institute of Biotechnology, University of Helsinki, PO Box 56, 00014 Helsinki, Finland; CAS Key Laboratory of Molecular Virology and Immunology, Institute Pasteur of Shanghai, Chinese Academy of Sciences, Life Science Research Building 320, Yueyang Road, Xuhui District, 200031 Shanghai, China; University of Chinese Academy of Sciences, Yuquan Road No.19(A), Shijingshan District, 100049 Beijing, China
| | - Peter J Carman
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, 728 Clinical Research Bldg, 415 Curie Boulevard, Philadelphia, PA 19104, USA; Graduate Group in Biochemistry and Molecular Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Sari Tojkander
- Department of Veterinary Biosciences, Faculty of Veterinary Medicine, University of Helsinki, Agnes Sjöberginkatu 2, 00014 Helsinki, Finland
| | - Konstantin Kogan
- HiLIFE Institute of Biotechnology, University of Helsinki, PO Box 56, 00014 Helsinki, Finland
| | - Markku Varjosalo
- HiLIFE Institute of Biotechnology, University of Helsinki, PO Box 56, 00014 Helsinki, Finland
| | - Peter W Gunning
- School of Medical Sciences, UNSW, Sydney, Wallace Wurth Building, Sydney, NSW 2052, Australia
| | - Roberto Dominguez
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, 728 Clinical Research Bldg, 415 Curie Boulevard, Philadelphia, PA 19104, USA
| | - Pekka Lappalainen
- HiLIFE Institute of Biotechnology, University of Helsinki, PO Box 56, 00014 Helsinki, Finland.
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Prill K, Dawson JF. Assembly and Maintenance of Sarcomere Thin Filaments and Associated Diseases. Int J Mol Sci 2020; 21:E542. [PMID: 31952119 PMCID: PMC7013991 DOI: 10.3390/ijms21020542] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Revised: 01/06/2020] [Accepted: 01/12/2020] [Indexed: 12/22/2022] Open
Abstract
Sarcomere assembly and maintenance are essential physiological processes required for cardiac and skeletal muscle function and organism mobility. Over decades of research, components of the sarcomere and factors involved in the formation and maintenance of this contractile unit have been identified. Although we have a general understanding of sarcomere assembly and maintenance, much less is known about the development of the thin filaments and associated factors within the sarcomere. In the last decade, advancements in medical intervention and genome sequencing have uncovered patients with novel mutations in sarcomere thin filaments. Pairing this sequencing with reverse genetics and the ability to generate patient avatars in model organisms has begun to deepen our understanding of sarcomere thin filament development. In this review, we provide a summary of recent findings regarding sarcomere assembly, maintenance, and disease with respect to thin filaments, building on the previous knowledge in the field. We highlight debated and unknown areas within these processes to clearly define open research questions.
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Affiliation(s)
| | - John F. Dawson
- Centre for Cardiovascular Investigations, Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON N1G 2W1, Canada;
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9
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Scicchitano BM, Dobrowolny G, Sica G, Musarò A. Molecular Insights into Muscle Homeostasis, Atrophy and Wasting. Curr Genomics 2018; 19:356-369. [PMID: 30065611 PMCID: PMC6030854 DOI: 10.2174/1389202919666180101153911] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Muscle homeostasis is guaranteed by a delicate balance between synthesis and degradation of cell proteins and its alteration leads to muscle wasting and diseases. In this review, we describe the major anabolic pathways that are involved in muscle growth and homeostasis and the proteolytic systems that are over-activated in muscle pathologies. Modulation of these pathways comprises an attractive target for drug intervention.
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Affiliation(s)
- Bianca Maria Scicchitano
- Istituto di Istologia e Embriologia, Università Cattolica del Sacro Cuore, Fondazione Policlinico Universitario Agostino Gemelli, Largo Francesco Vito 1-00168, Roma, Italy
| | - Gabriella Dobrowolny
- Center for Life Nano Science@Sapienza, Istituto Italiano di Tecnologia, Rome, Italy
| | - Gigliola Sica
- Istituto di Istologia e Embriologia, Università Cattolica del Sacro Cuore, Fondazione Policlinico Universitario Agostino Gemelli, Largo Francesco Vito 1-00168, Roma, Italy
| | - Antonio Musarò
- Center for Life Nano Science@Sapienza, Istituto Italiano di Tecnologia, Rome, Italy
- DAHFMO-Unit of Histology and Medical Embryology, Sapienza University of Rome, Laboratory Affiliated to Istituto Pasteur Italia - Fondazione Cenci Bolognetti, Rome, Italy
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10
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Zhou CY, Wang Y, Pan DD, Sun YY, Cao JX. The effect of ATP marination on the depolymerization of actin filament in goose muscles during postmortem conditioning. Poult Sci 2018; 97:684-694. [PMID: 29121270 DOI: 10.3382/ps/pex318] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Accepted: 09/29/2017] [Indexed: 01/29/2023] Open
Abstract
In order to study the tenderization mechanism of ATP treatments by depolymerizing actin filaments, breast muscles of Eastern Zhejiang White Geese were randomly divided into 3 groups: control, 10 and 20 mM groups. Shear force (SF), sarcomere length (SL) and myofibrillar fraction index (MFI), the content of F-actin and G-actin, the expression of actin associated proteins (cofilins and tropomodulins) were investigated during conditioning. In 20 mM group, cofilins content increased from 48 to 168 h, while tropomodulins decreased; the content of F-actin decreased from 24 to 168 h, while the increased G-actin was observed upto 48 h. In the control, the degraded tropomodulins were observed at 168 h, and the increased cofilins and G-actin were detected at the same time; the increase of MFI and decrease of F-actin content were shown at 96 and 168 h. Compared to control group, 20 mM group accelerated the transformation of F-actin into G-actin; it showed higher SL and MFI, and lower SF at 48, 96 and 168 h, respectively. We concluded that depolymerization of actin filaments, which was regulated by cofilins and tropomodulins, contributed to myofibrillar fraction and low SF during conditioning.
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Affiliation(s)
- Chang-Yu Zhou
- Key Laboratory of Animal Protein Food Processing Technology of Zhejiang Province, Ningbo University, Ningbo 315211, China
| | - Ying Wang
- Key Laboratory of Animal Protein Food Processing Technology of Zhejiang Province, Ningbo University, Ningbo 315211, China
| | - Dao-Dong Pan
- Key Laboratory of Animal Protein Food Processing Technology of Zhejiang Province, Ningbo University, Ningbo 315211, China
| | - Yang-Ying Sun
- Key Laboratory of Animal Protein Food Processing Technology of Zhejiang Province, Ningbo University, Ningbo 315211, China
| | - Jin-Xuan Cao
- Key Laboratory of Animal Protein Food Processing Technology of Zhejiang Province, Ningbo University, Ningbo 315211, China
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11
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The effect of CaCl 2 marination on the tenderizing pathway of goose meat during conditioning. Food Res Int 2017; 102:487-492. [PMID: 29195976 DOI: 10.1016/j.foodres.2017.09.014] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Revised: 09/05/2017] [Accepted: 09/08/2017] [Indexed: 11/22/2022]
Abstract
In order to figure out the effect of CaCl2 on the tenderizing pathway of goose meat, breast muscles of thirty-two Eastern Zhejiang White Geese were divided into three treatments: the control, 150 and 300mM CaCl2. Shear force, myofibrillar fraction index (MFI), actin filaments and F-actin, G-actin and tropomodulins (Tmods) levels were investigated during 168h. Results showed that 300mM treatment had lower shear force at 48, 96 and 168h and higher MFI at 24, 48, 96 and 168h than the control. The rate of actin filaments disruption, the decrease of F-actin, the degradation of Tmods, the increase of G-actin in 300mM treatment was faster than 150mM treatment; the rate in the control was the slowest among treatments. CaCl2 accelerated the transformation of F-actin into G-actin. We concluded that CaCl2 tenderized goose meat by depolymerizing actin filaments and cleaving Tmods.
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12
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Fowler VM, Dominguez R. Tropomodulins and Leiomodins: Actin Pointed End Caps and Nucleators in Muscles. Biophys J 2017; 112:1742-1760. [PMID: 28494946 DOI: 10.1016/j.bpj.2017.03.034] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Revised: 03/27/2017] [Accepted: 03/30/2017] [Indexed: 12/29/2022] Open
Abstract
Cytoskeletal structures characterized by actin filaments with uniform lengths, including the thin filaments of striated muscles and the spectrin-based membrane skeleton, use barbed and pointed-end capping proteins to control subunit addition/dissociation at filament ends. While several proteins cap the barbed end, tropomodulins (Tmods), a family of four closely related isoforms in vertebrates, are the only proteins known to specifically cap the pointed end. Tmods are ∼350 amino acids in length, and comprise alternating tropomyosin- and actin-binding sites (TMBS1, ABS1, TMBS2, and ABS2). Leiomodins (Lmods) are related in sequence to Tmods, but display important differences, including most notably the lack of TMBS2 and the presence of a C-terminal extension featuring a proline-rich domain and an actin-binding WASP-Homology 2 domain. The Lmod subfamily comprises three somewhat divergent isoforms expressed predominantly in muscle cells. Biochemically, Lmods differ from Tmods, acting as powerful nucleators of actin polymerization, not capping proteins. Structurally, Lmods and Tmods display crucial differences that correlate well with their different biochemical activities. Physiologically, loss of Lmods in striated muscle results in cardiomyopathy or nemaline myopathy, whereas complete loss of Tmods leads to failure of myofibril assembly and developmental defects. Yet, interpretation of some of the in vivo data has led to the idea that Tmods and Lmods are interchangeable or, at best, different variants of two subfamilies of pointed-end capping proteins. Here, we review and contrast the existing literature on Tmods and Lmods, and propose a model of Lmod function that attempts to reconcile the in vitro and in vivo data, whereby Lmods nucleate actin filaments that are subsequently capped by Tmods during sarcomere assembly, turnover, and repair.
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Affiliation(s)
- Velia M Fowler
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, California.
| | - Roberto Dominguez
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.
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13
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Chen Q, Zhang L, Zhang Y, Mao Q, Wei T. Tubules of plant reoviruses exploit tropomodulin to regulate actin-based tubule motility in insect vector. Sci Rep 2017; 7:38563. [PMID: 28067229 PMCID: PMC5220352 DOI: 10.1038/srep38563] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2016] [Accepted: 11/10/2016] [Indexed: 12/13/2022] Open
Abstract
Plant reoviruses are known to exploit virion-packaging tubules formed by virus-encoding non-structural proteins for viral spread in insect vectors. Tubules are propelled by actin-based tubule motility (ABTM) to overcome membrane or tissue barriers in insect vectors. To further understand which insect factors mediate ABTM, we utilized yeast two-hybrid and bimolecular fluorescence complementation assays to test interactions between tubule protein Pns10 of rice dwarf virus (RDV), a plant reovirus, and proteins of its insect vector, the leafhopper Nephotettix cincticeps. Tropomodulin (Tmod), vitellogenin, and lipophorin precursor of N. cincticep displayed positive and strong interaction with Pns10, and actin-associated protein Tmod interacted with Pns10 in pull-down assay and the co-immunoprecipitation system. Further, we determined Pns10 tubules associated with Tmod in cultured cells and midgut of N. cincticep. The expression dynamic of Tmod was consistent with that of Pns10 and the fluctuation of RDV accumulation. Knockdown of Tmod inhibited the Pns10 expression and viral accumulation, thus decreasing the viruliferous rates of leafhopper. These results suggested that Tmod was involved in viral spread by directly interacting with Pns10 tubules, finally promoting RDV infection. This study provided direct evidence of plant reoviruses utilizing an actin-associated protein to manipulate ABTM in insect vectors, thus facilitating viral spread.
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Affiliation(s)
- Qian Chen
- Fujian Province Key Laboratory of Plant Virology, Institute of Plant Virology, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, P.R. China
| | - Linghua Zhang
- Fujian Province Key Laboratory of Plant Virology, Institute of Plant Virology, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, P.R. China
| | - Yanshuang Zhang
- Fujian Province Key Laboratory of Plant Virology, Institute of Plant Virology, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, P.R. China
| | - Qianzhuo Mao
- Fujian Province Key Laboratory of Plant Virology, Institute of Plant Virology, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, P.R. China
| | - Taiyun Wei
- Fujian Province Key Laboratory of Plant Virology, Institute of Plant Virology, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, P.R. China
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14
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Smart N, Riegler J, Turtle CW, Lygate CA, McAndrew DJ, Gehmlich K, Dubé KN, Price AN, Muthurangu V, Taylor AM, Lythgoe MF, Redwood C, Riley PR. Aberrant developmental titin splicing and dysregulated sarcomere length in Thymosin β4 knockout mice. J Mol Cell Cardiol 2017; 102:94-107. [PMID: 27914791 PMCID: PMC5319848 DOI: 10.1016/j.yjmcc.2016.10.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/09/2016] [Revised: 10/20/2016] [Accepted: 10/22/2016] [Indexed: 02/07/2023]
Abstract
Sarcomere assembly is a highly orchestrated and dynamic process which adapts, during perinatal development, to accommodate growth of the heart. Sarcomeric components, including titin, undergo an isoform transition to adjust ventricular filling. Many sarcomeric genes have been implicated in congenital cardiomyopathies, such that understanding developmental sarcomere transitions will inform the aetiology and treatment. We sought to determine whether Thymosin β4 (Tβ4), a peptide that regulates the availability of actin monomers for polymerization in non-muscle cells, plays a role in sarcomere assembly during cardiac morphogenesis and influences adult cardiac function. In Tβ4 null mice, immunofluorescence-based sarcomere analyses revealed shortened thin filament, sarcomere and titin spring length in cardiomyocytes, associated with precocious up-regulation of the short titin isoforms during the postnatal splicing transition. By magnetic resonance imaging, this manifested as diminished stroke volume and limited contractile reserve in adult mice. Extrapolating to an in vitro cardiomyocyte model, the altered postnatal splicing was corrected with addition of synthetic Tβ4, whereby normal sarcomere length was restored. Our data suggest that Tβ4 is required for setting correct sarcomere length and for appropriate splicing of titin, not only in the heart but also in skeletal muscle. Distinguishing between thin filament extension and titin splicing as the primary defect is challenging, as these events are intimately linked. The regulation of titin splicing is a previously unrecognised role of Tβ4 and gives preliminary insight into a mechanism by which titin isoforms may be manipulated to correct cardiac dysfunction.
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Affiliation(s)
- Nicola Smart
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK.
| | - Johannes Riegler
- Centre for Advanced Biomedical Imaging, Department of Medicine, University College London (UCL), London, UK
| | - Cameron W Turtle
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Craig A Lygate
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Debra J McAndrew
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Katja Gehmlich
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | | | - Anthony N Price
- Centre for Advanced Biomedical Imaging, Department of Medicine, University College London (UCL), London, UK
| | - Vivek Muthurangu
- Centre for Cardiovascular Imaging, UCL Institute of Cardiovascular Science, London, UK
| | - Andrew M Taylor
- Centre for Cardiovascular Imaging, UCL Institute of Cardiovascular Science, London, UK
| | - Mark F Lythgoe
- Centre for Advanced Biomedical Imaging, Department of Medicine, University College London (UCL), London, UK
| | - Charles Redwood
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Paul R Riley
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK
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15
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Abstract
PURPOSE OF REVIEW This article discusses recent advances and unsolved questions in our understanding of actin filament organization and dynamics in the red blood cell (RBC) membrane skeleton, a two-dimensional quasi-hexagonal network consisting of (α1β1)2-spectrin tetramers interconnecting short actin filament-based junctional complexes. RECENT FINDINGS In contrast to the long-held view that RBC actin filaments are static structures that do not exchange subunits with the cytosol, RBC actin filaments are dynamic structures that undergo subunit exchange and turnover, as evidenced by monomer incorporation experiments with rhodamine-actin and filament disruption experiments with actin-targeting drugs. The malaria-causing parasite, Plasmodium falciparum, co-opts RBC actin dynamics to construct aberrantly branched actin filament networks. Even though RBC actin filaments are dynamic, RBC actin filament lengths are highly uniform (∼37 nm). RBC actin filament lengths are thought to be stabilized by the capping proteins, tropomodulin-1 and αβ-adducin, as well as the side-binding protein tropomyosin, present in an equimolar combination of two isoforms, TM5b (Tpm1.9) and TM5NM1 (Tpm3.1). SUMMARY New evidence indicates that RBC actin filaments are not simply passive cytolinkers, but rather dynamic structures whose assembly and disassembly play important roles in RBC membrane function.
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16
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Chang H, Jiang SF, Dang K, Wang HP, Xu SH, Gao YF. iTRAQ-based proteomic analysis of myofibrillar contents and relevant synthesis and proteolytic proteins in soleus muscle of hibernating Daurian ground squirrels ( Spermophilus dauricus). Proteome Sci 2016; 14:16. [PMID: 27833457 PMCID: PMC5101720 DOI: 10.1186/s12953-016-0105-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2016] [Accepted: 11/01/2016] [Indexed: 01/07/2023] Open
Abstract
BACKGROUND Daurian ground squirrels (Spermophilus dauricus) deviate from significant increase of protein catabolism and loss of myofibrillar contents during long period of hibernation inactivity. METHODS Here we use iTRAQ based quantitative analysis to examine proteomic changes in the soleus of squirrels in pre-hibernation, hibernation and post-hibernation states. The total proteolysis rate of soleus was measured by the release of the essential amino acid tyrosine from isolated muscles. Immunofluorescent analysis was used to determine muscle fiber cross-sectional area. Western blot was used for the validation of the quantitative proteomic analysis. RESULTS The proteomic responses to hibernation had a 0.4- to 0.8-fold decrease in the myofibrillar contractile protein levels of myosin-3, myosin-13 and actin, but a 2.1-fold increase in myosin-2 compared to pre-hibernation group. Regulatory proteins such as troponin C and tropomodulin-1 were 1.4-fold up-regulated and 0.7-fold down-regulated, respectively, in hibernation compared to pre-hibernation group. Moreover, 10 proteins with proteolytic function in hibernation, which was less than 14 proteins in the post-hibernation group, were up-regulated relative to the pre-hibernation group. The total proteolysis rates of soleus in hibernation and post-hibernation groups were significantly inhibited as compared with pre-hibernation group. CONCLUSION These findings suggest that the myofibrillar remodeling and partial suppression of myofibrillar proteolysis were likely responsible for preventing skeletal muscle atrophy during prolonged disuse in hibernation. This is the first study where the myofibrillar contents and relevant synthesis and proteolytic proteins in slow soleus was discussed based on proteomic investigation performed on wild Daurian ground squirrels. Our results lay the foundation for further research in preventing disuse-induced skeletal muscle atrophy in mammals.
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Affiliation(s)
- Hui Chang
- Key Laboratory of Resource Biology and Biotechnology in Western China (College of Life Sciences, Northwest University), Ministry of Education, Xi’an, 710069 People’s Republic of China
- Shaanxi Key Laboratory for Animal Conservation, Northwest University, Xi’an, 710069 People’s Republic of China
| | - Shan-Feng Jiang
- Key Laboratory of Resource Biology and Biotechnology in Western China (College of Life Sciences, Northwest University), Ministry of Education, Xi’an, 710069 People’s Republic of China
| | - Kai Dang
- Key Laboratory of Resource Biology and Biotechnology in Western China (College of Life Sciences, Northwest University), Ministry of Education, Xi’an, 710069 People’s Republic of China
| | - Hui-Ping Wang
- Key Laboratory of Resource Biology and Biotechnology in Western China (College of Life Sciences, Northwest University), Ministry of Education, Xi’an, 710069 People’s Republic of China
| | - Shen-Hui Xu
- Key Laboratory of Resource Biology and Biotechnology in Western China (College of Life Sciences, Northwest University), Ministry of Education, Xi’an, 710069 People’s Republic of China
| | - Yun-Fang Gao
- Key Laboratory of Resource Biology and Biotechnology in Western China (College of Life Sciences, Northwest University), Ministry of Education, Xi’an, 710069 People’s Republic of China
- Shaanxi Key Laboratory for Animal Conservation, Northwest University, Xi’an, 710069 People’s Republic of China
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17
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Zhou C, Wang Y, Pan D, Sun Y, Cao J. The effect of Cytochalasin B and Jasplakinolide on depolymerization of actin filaments in goose muscles during postmortem conditioning. Food Res Int 2016; 90:1-7. [PMID: 29195861 DOI: 10.1016/j.foodres.2016.10.032] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2016] [Revised: 10/20/2016] [Accepted: 10/23/2016] [Indexed: 11/20/2022]
Abstract
Breast muscles of twenty-four Eastern Zhejiang White Geese were randomly divided into three groups: control, Cytochalasin B (Cyt B) and Jasplakinolide (Jasp) treatments during postmortem conditioning. The myofibrillar fraction index (MFI), actin filaments and the levels of F-actin, G-actin and actin associated proteins (cofilins and tropomodulins) during conditioning were investigated. In control, the degraded tropomodulins, increased G-actin and disrupted actin filaments were observed at 4 and 7days; the increase of MFI and decrease of F-actin content were shown during conditioning. Cyt B treatments accelerated the transformation from F-actin to G-actin, weakened actin filaments and increased MFI compared to the control, while Jasp gained the opposite effect against Cyt B. We concluded that depolymerization of actin filaments regulated by tropomodulins contributed to myofibrillar fraction during conditioning. This work provided a new pathway of tenderization by the depolymerization of actin filaments.
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Affiliation(s)
- Changyu Zhou
- Key Laboratory of Animal Protein Food Processing Technology of Zhejiang Province, Ningbo University, Ningbo 315211, China
| | - Ying Wang
- Key Laboratory of Animal Protein Food Processing Technology of Zhejiang Province, Ningbo University, Ningbo 315211, China
| | - Daodong Pan
- Key Laboratory of Animal Protein Food Processing Technology of Zhejiang Province, Ningbo University, Ningbo 315211, China
| | - Yangying Sun
- Key Laboratory of Animal Protein Food Processing Technology of Zhejiang Province, Ningbo University, Ningbo 315211, China
| | - Jinxuan Cao
- Key Laboratory of Animal Protein Food Processing Technology of Zhejiang Province, Ningbo University, Ningbo 315211, China.
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18
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Gokhin DS, Fowler VM. Software-based measurement of thin filament lengths: an open-source GUI for Distributed Deconvolution analysis of fluorescence images. J Microsc 2016; 265:11-20. [PMID: 27644080 DOI: 10.1111/jmi.12456] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2016] [Revised: 06/09/2016] [Accepted: 07/19/2016] [Indexed: 12/25/2022]
Abstract
The periodically arranged thin filaments within the striated myofibrils of skeletal and cardiac muscle have precisely regulated lengths, which can change in response to developmental adaptations, pathophysiological states, and genetic perturbations. We have developed a user-friendly, open-source ImageJ plugin that provides a graphical user interface (GUI) for super-resolution measurement of thin filament lengths by applying Distributed Deconvolution (DDecon) analysis to periodic line scans collected from fluorescence images. In the workflow presented here, we demonstrate thin filament length measurement using a phalloidin-stained cryosection of mouse skeletal muscle. The DDecon plugin is also capable of measuring distances of any periodically localized fluorescent signal from the Z- or M-line, as well as distances between successive Z- or M-lines, providing a broadly applicable tool for quantitative analysis of muscle cytoarchitecture. These functionalities can also be used to analyse periodic fluorescence signals in nonmuscle cells.
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Affiliation(s)
- David S Gokhin
- Department of Cell and Molecular Biology, The Scripps Research Institute, La Jolla, California, U.S.A
| | - Velia M Fowler
- Department of Cell and Molecular Biology, The Scripps Research Institute, La Jolla, California, U.S.A
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19
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Mazelet L, Parker MO, Li M, Arner A, Ashworth R. Role of Active Contraction and Tropomodulins in Regulating Actin Filament Length and Sarcomere Structure in Developing Zebrafish Skeletal Muscle. Front Physiol 2016; 7:91. [PMID: 27065876 PMCID: PMC4814503 DOI: 10.3389/fphys.2016.00091] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2015] [Accepted: 02/26/2016] [Indexed: 01/13/2023] Open
Abstract
Whilst it is recognized that contraction plays an important part in maintaining the structure and function of mature skeletal muscle, its role during development remains undefined. In this study the role of movement in skeletal muscle maturation was investigated in intact zebrafish embryos using a combination of genetic and pharmacological approaches. An immotile mutant line (cacnb1 (ts25) ) which lacks functional voltage-gated calcium channels (dihydropyridine receptors) in the muscle and pharmacological immobilization of embryos with a reversible anesthetic (Tricaine), allowed the study of paralysis (in mutants and anesthetized fish) and recovery of movement (reversal of anesthetic treatment). The effect of paralysis in early embryos (aged between 17 and 24 hours post-fertilization, hpf) on skeletal muscle structure at both myofibrillar and myofilament level was determined using both immunostaining with confocal microscopy and small angle X-ray diffraction. The consequences of paralysis and subsequent recovery on the localization of the actin capping proteins Tropomodulin 1 & 4 (Tmod) in fish aged from 17 hpf until 42 hpf was also assessed. The functional consequences of early paralysis were investigated by examining the mechanical properties of the larval muscle. The length-force relationship, active and passive tension, was measured in immotile, recovered and control skeletal muscle at 5 and 7 day post-fertilization (dpf). Recovery of muscle function was also assessed by examining swimming patterns in recovered and control fish. Inhibition of the initial embryonic movements (up to 24 hpf) resulted in an increase in myofibril length and a decrease in width followed by almost complete recovery in both moving and paralyzed fish by 42 hpf. In conclusion, myofibril organization is regulated by a dual mechanism involving movement-dependent and movement-independent processes. The initial contractile event itself drives the localization of Tmod1 to its sarcomeric position, capping the actin pointed ends and ultimately regulating actin length. This study demonstrates that both contraction and contractile-independent mechanisms are important for the regulation of myofibril organization, which in turn is necessary for establishing proper skeletal muscle structure and function during development in vivo in zebrafish.
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Affiliation(s)
- Lise Mazelet
- School of Biological and Chemical Sciences, Queen Mary, University of London London, UK
| | - Matthew O Parker
- School of Health Sciences and Social Work, University of Portsmouth Portsmouth, UK
| | - Mei Li
- Department of Physiology and Pharmacology, Karolinska Institutet Stockholm, Sweden
| | - Anders Arner
- Department of Physiology and Pharmacology, Karolinska Institutet Stockholm, Sweden
| | - Rachel Ashworth
- The Blizard Institute/Institute of Health Sciences Education, Barts and The London School of Medicine and Dentistry London, UK
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20
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Gokhin DS, Ochala J, Domenighetti AA, Fowler VM. Tropomodulin 1 directly controls thin filament length in both wild-type and tropomodulin 4-deficient skeletal muscle. Development 2015; 142:4351-62. [PMID: 26586224 DOI: 10.1242/dev.129171] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2015] [Accepted: 11/05/2015] [Indexed: 01/10/2023]
Abstract
The sarcomeric tropomodulin (Tmod) isoforms Tmod1 and Tmod4 cap thin filament pointed ends and functionally interact with the leiomodin (Lmod) isoforms Lmod2 and Lmod3 to control myofibril organization, thin filament lengths, and actomyosin crossbridge formation in skeletal muscle fibers. Here, we show that Tmod4 is more abundant than Tmod1 at both the transcript and protein level in a variety of muscle types, but the relative abundances of sarcomeric Tmods are muscle specific. We then generate Tmod4(-/-) mice, which exhibit normal thin filament lengths, myofibril organization, and skeletal muscle contractile function owing to compensatory upregulation of Tmod1, together with an Lmod isoform switch wherein Lmod3 is downregulated and Lmod2 is upregulated. However, RNAi depletion of Tmod1 from either wild-type or Tmod4(-/-) muscle fibers leads to thin filament elongation by ∼15%. Thus, Tmod1 per se, rather than total sarcomeric Tmod levels, controls thin filament lengths in mouse skeletal muscle, whereas Tmod4 appears to be dispensable for thin filament length regulation. These findings identify Tmod1 as the key direct regulator of thin filament length in skeletal muscle, in both adult muscle homeostasis and in developmentally compensated contexts.
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Affiliation(s)
- David S Gokhin
- Department of Cell and Molecular Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Julien Ochala
- Centre of Human and Aerospace Physiological Sciences, King's College London, London SE1 1UL, UK
| | - Andrea A Domenighetti
- Department of Physical Medicine and Rehabilitation, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA Rehabilitation Institute of Chicago, Chicago, IL 60611, USA
| | - Velia M Fowler
- Department of Cell and Molecular Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
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21
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Mu W, Wang X, Zhang X, Zhu S, Sun D, Ka W, Sung LA, Yao W. Fluid Shear Stress Upregulates E-Tmod41 via miR-23b-3p and Contributes to F-Actin Cytoskeleton Remodeling during Erythropoiesis. PLoS One 2015; 10:e0136607. [PMID: 26308647 PMCID: PMC4550387 DOI: 10.1371/journal.pone.0136607] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2015] [Accepted: 08/06/2015] [Indexed: 11/22/2022] Open
Abstract
The membrane skeleton of mature erythrocyte is formed during erythroid differentiation. Fluid shear stress is one of the main factors that promote embryonic hematopoiesis, however, its effects on erythroid differentiation and cytoskeleton remodeling are unclear. Erythrocyte tropomodulin of 41 kDa (E-Tmod41) caps the pointed end of actin filament (F-actin) and is critical for the formation of hexagonal topology of erythrocyte membrane skeleton. Our study focused on the regulation of E-Tmod41 and its role in F-actin cytoskeleton remodeling during erythroid differentiation induced by fluid shear stress. Mouse erythroleukemia (MEL) cells and embryonic erythroblasts were subjected to fluid shear stress (5 dyn/cm2) and erythroid differentiation was induced in both cells. F-actin content and E-Tmod41 expression were significantly increased in MEL cells after shearing. E-Tmod41 overexpression resulted in a significant increase in F-actin content, while the knockdown of E-Tmod41 generated the opposite result. An E-Tmod 3’UTR targeting miRNA, miR-23b-3p, was found suppressed by shear stress. When miR-23b-3p level was overexpressed / inhibited, both E-Tmod41 protein level and F-actin content were reduced / augmented. Furthermore, among the two alternative promoters of E-Tmod, PE0 (upstream of exon 0), which mainly drives the expression of E-Tmod41, was found activated by shear stress. In conclusion, our results suggest that fluid shear stress could induce erythroid differentiation and F-actin cytoskeleton remodeling. It upregulates E-Tmod41 expression through miR-23b-3p suppression and PE0 promoter activation, which, in turn, contributes to F-actin cytoskeleton remodeling.
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Affiliation(s)
- Weiyun Mu
- Hemorheology Center, Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, 100191, China
| | - Xifu Wang
- Department of Emergency, Beijing Anzhen hospital, Capital Medical University, Beijing, 100029, China
| | - Xiaolan Zhang
- Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Sida Zhu
- Hemorheology Center, Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, 100191, China
| | - Dagong Sun
- Hemorheology Center, Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, 100191, China
| | - Weibo Ka
- Hemorheology Center, Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, 100191, China
| | - Lanping Amy Sung
- Department of Bioengineering, University of California, San Diego, La Jolla, CA 92093, United States of America
| | - Weijuan Yao
- Hemorheology Center, Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, 100191, China
- * E-mail:
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22
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Regulation of actin polymerization by tropomodulin-3 controls megakaryocyte actin organization and platelet biogenesis. Blood 2015; 126:520-30. [PMID: 25964668 DOI: 10.1182/blood-2014-09-601484] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2014] [Accepted: 05/04/2015] [Indexed: 01/02/2023] Open
Abstract
The actin cytoskeleton is important for platelet biogenesis. Tropomodulin-3 (Tmod3), the only Tmod isoform detected in platelets and megakaryocytes (MKs), caps actin filament (F-actin) pointed ends and binds tropomyosins (TMs), regulating actin polymerization and stability. To determine the function of Tmod3 in platelet biogenesis, we studied Tmod3(-/-) embryos, which are embryonic lethal by E18.5. Tmod3(-/-) embryos often show hemorrhaging at E14.5 with fewer and larger platelets, indicating impaired platelet biogenesis. MK numbers are moderately increased in Tmod3(-/-) fetal livers, with only a slight increase in the 8N population, suggesting that MK differentiation is not significantly affected. However, Tmod3(-/-) MKs fail to develop a normal demarcation membrane system (DMS), and cytoplasmic organelle distribution is abnormal. Moreover, cultured Tmod3(-/-) MKs exhibit impaired proplatelet formation with a wide range of proplatelet bud sizes, including abnormally large proplatelet buds containing incorrect numbers of von Willebrand factor-positive granules. Tmod3(-/-) MKs exhibit F-actin disturbances, and Tmod3(-/-) MKs spreading on collagen fail to polymerize F-actin into actomyosin contractile bundles. Tmod3 associates with TM4 and the F-actin cytoskeleton in wild-type MKs, and confocal microscopy reveals that Tmod3, TM4, and F-actin partially colocalize near the membrane of proplatelet buds. In contrast, the abnormally large proplatelets from Tmod3(-/-) MKs show increased F-actin and redistribution of F-actin and TM4 from the cortex to the cytoplasm, but normal microtubule coil organization. We conclude that F-actin capping by Tmod3 regulates F-actin organization in mouse fetal liver-derived MKs, thereby controlling MK cytoplasmic morphogenesis, including DMS formation and organelle distribution, as well as proplatelet formation and sizing.
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23
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Guellich A, Negroni E, Decostre V, Demoule A, Coirault C. Altered cross-bridge properties in skeletal muscle dystrophies. Front Physiol 2014; 5:393. [PMID: 25352808 PMCID: PMC4196474 DOI: 10.3389/fphys.2014.00393] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2014] [Accepted: 09/23/2014] [Indexed: 12/20/2022] Open
Abstract
Force and motion generated by skeletal muscle ultimately depends on the cyclical interaction of actin with myosin. This mechanical process is regulated by intracellular Ca2+ through the thin filament-associated regulatory proteins i.e.; troponins and tropomyosin. Muscular dystrophies are a group of heterogeneous genetic affections characterized by progressive degeneration and weakness of the skeletal muscle as a consequence of loss of muscle tissue which directly reduces the number of potential myosin cross-bridges involved in force production. Mutations in genes responsible for skeletal muscle dystrophies (MDs) have been shown to modify the function of contractile proteins and cross-bridge interactions. Altered gene expression or RNA splicing or post-translational modifications of contractile proteins such as those related to oxidative stress, may affect cross-bridge function by modifying key proteins of the excitation-contraction coupling. Micro-architectural change in myofilament is another mechanism of altered cross-bridge performance. In this review, we provide an overview about changes in cross-bridge performance in skeletal MDs and discuss their ultimate impacts on striated muscle function.
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Affiliation(s)
- Aziz Guellich
- Service de Cardiologie, Hôpital Henri Mondor, University Paris-Est Créteil Créteil, France ; Equipe 8, Institut National de la Santé et de la Recherche Médicale Créteil, France
| | - Elisa Negroni
- UMRS 974, Institut National de la Santé et de la Recherche Médicale Paris, France ; UM 76, Université Pierre et Marie Curie, Sorbonne Universités Paris, France ; UMR 7215, Centre National de la Recherche Scientifique Paris, France ; Institut de Myologie Paris, France
| | | | - Alexandre Demoule
- UMRS 974, Institut National de la Santé et de la Recherche Médicale Paris, France ; UM 76, Université Pierre et Marie Curie, Sorbonne Universités Paris, France ; UMR 7215, Centre National de la Recherche Scientifique Paris, France ; Institut de Myologie Paris, France ; Assistance Publique-Hopitaux de Paris, Service de Pneumologie et Reanimation Medicale Paris, France
| | - Catherine Coirault
- UMRS 974, Institut National de la Santé et de la Recherche Médicale Paris, France ; UM 76, Université Pierre et Marie Curie, Sorbonne Universités Paris, France ; UMR 7215, Centre National de la Recherche Scientifique Paris, France ; Institut de Myologie Paris, France
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24
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Gokhin DS, Dubuc EA, Lian KQ, Peters LL, Fowler VM. Alterations in thin filament length during postnatal skeletal muscle development and aging in mice. Front Physiol 2014; 5:375. [PMID: 25324783 PMCID: PMC4178374 DOI: 10.3389/fphys.2014.00375] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2014] [Accepted: 09/10/2014] [Indexed: 11/13/2022] Open
Abstract
The lengths of the sarcomeric thin filaments vary in a skeletal muscle-specific manner and help specify the physiological properties of skeletal muscle. Since the extent of overlap between the thin and thick filaments determines the amount of contractile force that a sarcomere can actively produce, thin filament lengths are accurate predictors of muscle-specific sarcomere length-tension relationships and sarcomere operating length ranges. However, the striking uniformity of thin filament lengths within sarcomeres, specified during myofibril assembly, has led to the widely held assumption that thin filament lengths remain constant throughout an organism's lifespan. Here, we rigorously tested this assumption by using computational super-resolution image analysis of confocal fluorescence images to explore the effects of postnatal development and aging on thin filament length in mice. We found that thin filaments shorten in postnatal tibialis anterior (TA) and gastrocnemius muscles between postnatal days 7 and 21, consistent with the developmental program of myosin heavy chain (MHC) gene expression in this interval. By contrast, thin filament lengths in TA and extensor digitorum longus (EDL) muscles remained constant between 2 mo and 2 yr of age, while thin filament lengths in soleus muscle became shorter, suggestive of a slow-muscle-specific mechanism of thin filament destabilization associated with aging. Collectively, these data are the first to show that thin filament lengths change as part of normal skeletal muscle development and aging, motivating future investigations into the cellular and molecular mechanisms underlying thin filament adaptation across the lifespan.
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Affiliation(s)
- David S Gokhin
- Department of Cell and Molecular Biology, The Scripps Research Institute La Jolla, CA, USA
| | - Emily A Dubuc
- Department of Cell and Molecular Biology, The Scripps Research Institute La Jolla, CA, USA
| | - Kendra Q Lian
- Department of Cell and Molecular Biology, The Scripps Research Institute La Jolla, CA, USA
| | | | - Velia M Fowler
- Department of Cell and Molecular Biology, The Scripps Research Institute La Jolla, CA, USA
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25
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Sirvent P, Douillard A, Galbes O, Ramonatxo C, Py G, Candau R, Lacampagne A. Effects of chronic administration of clenbuterol on contractile properties and calcium homeostasis in rat extensor digitorum longus muscle. PLoS One 2014; 9:e100281. [PMID: 24971566 PMCID: PMC4074032 DOI: 10.1371/journal.pone.0100281] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2013] [Accepted: 05/26/2014] [Indexed: 12/02/2022] Open
Abstract
Clenbuterol, a β2-agonist, induces skeletal muscle hypertrophy and a shift from slow-oxidative to fast-glycolytic muscle fiber type profile. However, the cellular mechanisms of the effects of chronic clenbuterol administration on skeletal muscle are not completely understood. As the intracellular Ca2+ concentration must be finely regulated in many cellular processes, the aim of this study was to investigate the effects of chronic clenbuterol treatment on force, fatigue, intracellular calcium (Ca2+) homeostasis and Ca2+-dependent proteolysis in fast-twitch skeletal muscles (the extensor digitorum longus, EDL, muscle), as they are more sensitive to clenbuterol-induced hypertrophy. Male Wistar rats were chronically treated with 4 mg.kg−1 clenbuterol or saline vehicle (controls) for 21 days. Confocal microscopy was used to evaluate sarcoplasmic reticulum Ca2+ load, Ca2+ -transient amplitude and Ca2+ spark properties. EDL muscles from clenbuterol-treated animals displayed hypertrophy, a shift from slow to fast fiber type profile and increased absolute force, while the relative force remained unchanged and resistance to fatigue decreased compared to control muscles from rats treated with saline vehicle. Compared to control animals, clenbuterol treatment decreased Ca2+-transient amplitude, Ca2+ spark amplitude and frequency and the sarcoplasmic reticulum Ca2+ load was markedly reduced. Conversely, calpain activity was increased by clenbuterol chronic treatment. These results indicate that chronic treatment with clenbuterol impairs Ca2+ homeostasis and this could contribute to the remodeling and functional impairment of fast-twitch skeletal muscle.
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Affiliation(s)
- Pascal Sirvent
- Clermont Université, Université Blaise Pascal, EA 3533, Laboratoire des Adaptations Métaboliques à l'Exercice en Conditions Physiologiques et Pathologiques (AME2P), BP 80026, Aubière, France; U1046, INSERM, Université Montpellier 1, Université Montpellier 2, 34295 Montpellier, France; CHRU Montpellier, 34295 Montpellier, France; National Institute for Agronomic Research (INRA), UMR 866 Muscular Dynamic and Metabolism, University of Montpellier, Montpellier, France
| | - Aymerick Douillard
- National Institute for Agronomic Research (INRA), UMR 866 Muscular Dynamic and Metabolism, University of Montpellier, Montpellier, France
| | - Olivier Galbes
- U1046, INSERM, Université Montpellier 1, Université Montpellier 2, 34295 Montpellier, France; CHRU Montpellier, 34295 Montpellier, France; National Institute for Agronomic Research (INRA), UMR 866 Muscular Dynamic and Metabolism, University of Montpellier, Montpellier, France
| | - Christelle Ramonatxo
- U1046, INSERM, Université Montpellier 1, Université Montpellier 2, 34295 Montpellier, France; CHRU Montpellier, 34295 Montpellier, France; National Institute for Agronomic Research (INRA), UMR 866 Muscular Dynamic and Metabolism, University of Montpellier, Montpellier, France
| | - Guillaume Py
- National Institute for Agronomic Research (INRA), UMR 866 Muscular Dynamic and Metabolism, University of Montpellier, Montpellier, France
| | - Robin Candau
- National Institute for Agronomic Research (INRA), UMR 866 Muscular Dynamic and Metabolism, University of Montpellier, Montpellier, France
| | - Alain Lacampagne
- U1046, INSERM, Université Montpellier 1, Université Montpellier 2, 34295 Montpellier, France; CHRU Montpellier, 34295 Montpellier, France
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