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Russell AP, Wallace MA, Kalanon M, Zacharewicz E, Della Gatta PA, Garnham A, Lamon S. Striated muscle activator of Rho signalling (STARS) is reduced in ageing human skeletal muscle and targeted by miR-628-5p. Acta Physiol (Oxf) 2017; 220:263-274. [PMID: 27739650 DOI: 10.1111/apha.12819] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2016] [Revised: 09/12/2016] [Accepted: 10/11/2016] [Indexed: 12/12/2022]
Abstract
AIM The striated muscle activator of Rho signalling (STARS) is a muscle-specific actin-binding protein. The STARS signalling pathway is activated by resistance exercise and is anticipated to play a role in signal mechanotransduction. Animal studies have reported a negative regulation of STARS signalling with age, but such regulation has not been investigated in humans. METHODS Ten young (18-30 years) and 10 older (60-75 years) subjects completed an acute bout of resistance exercise. Gene and protein expression of members of the STARS signalling pathway and miRNA expression of a subset of miRNAs, predicted or known to target members of STARS signalling pathway, were measured in muscle biopsies collected pre-exercise and 2 h post-exercise. RESULTS For the first time, we report a significant downregulation of the STARS protein in older subjects. However, there was no effect of age on the magnitude of STARS activation in response to an acute bout of exercise. Finally, we established that miR-628-5p, a miRNA regulated by age and exercise, binds to the STARS 3'UTR to directly downregulate its transcription. CONCLUSION This study describes for the first time the resistance exercise-induced regulation of STARS signalling in skeletal muscle from older humans and identifies a new miRNA involved in the transcriptional control of STARS.
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Affiliation(s)
- A. P. Russell
- Institute for Physical Activity and Nutrition (IPAN); School of Exercise and Nutrition Sciences; Deakin University; Geelong Vic. Australia
| | - M. A. Wallace
- Institute for Physical Activity and Nutrition (IPAN); School of Exercise and Nutrition Sciences; Deakin University; Geelong Vic. Australia
| | - M. Kalanon
- Institute for Physical Activity and Nutrition (IPAN); School of Exercise and Nutrition Sciences; Deakin University; Geelong Vic. Australia
| | - E. Zacharewicz
- Institute for Physical Activity and Nutrition (IPAN); School of Exercise and Nutrition Sciences; Deakin University; Geelong Vic. Australia
| | - P. A. Della Gatta
- Institute for Physical Activity and Nutrition (IPAN); School of Exercise and Nutrition Sciences; Deakin University; Geelong Vic. Australia
| | - A. Garnham
- Institute for Physical Activity and Nutrition (IPAN); School of Exercise and Nutrition Sciences; Deakin University; Geelong Vic. Australia
| | - S. Lamon
- Institute for Physical Activity and Nutrition (IPAN); School of Exercise and Nutrition Sciences; Deakin University; Geelong Vic. Australia
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STARS knockout attenuates hypoxia-induced pulmonary arterial hypertension by suppressing pulmonary arterial smooth muscle cell proliferation. Biomed Pharmacother 2017; 87:397-404. [DOI: 10.1016/j.biopha.2016.12.126] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2016] [Revised: 12/13/2016] [Accepted: 12/28/2016] [Indexed: 11/24/2022] Open
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Wallace MA, Della Gatta PA, Ahmad Mir B, Kowalski GM, Kloehn J, McConville MJ, Russell AP, Lamon S. Overexpression of Striated Muscle Activator of Rho Signaling (STARS) Increases C2C12 Skeletal Muscle Cell Differentiation. Front Physiol 2016; 7:7. [PMID: 26903873 PMCID: PMC4745265 DOI: 10.3389/fphys.2016.00007] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2015] [Accepted: 01/11/2016] [Indexed: 01/10/2023] Open
Abstract
Background: Skeletal muscle growth and regeneration depend on the activation of satellite cells, which leads to myocyte proliferation, differentiation and fusion with existing muscle fibers. Skeletal muscle cell proliferation and differentiation are tightly coordinated by a continuum of molecular signaling pathways. The striated muscle activator of Rho signaling (STARS) is an actin binding protein that regulates the transcription of genes involved in muscle cell growth, structure and function via the stimulation of actin polymerization and activation of serum-response factor (SRF) signaling. STARS mediates cell proliferation in smooth and cardiac muscle models; however, whether STARS overexpression enhances cell proliferation and differentiation has not been investigated in skeletal muscle cells. Results: We demonstrate for the first time that STARS overexpression enhances differentiation but not proliferation in C2C12 mouse skeletal muscle cells. Increased differentiation was associated with an increase in the gene levels of the myogenic differentiation markers Ckm, Ckmt2 and Myh4, the differentiation factor Igf2 and the myogenic regulatory factors (MRFs) Myf5 and Myf6. Exposing C2C12 cells to CCG-1423, a pharmacological inhibitor of SRF preventing the nuclear translocation of its co-factor MRTF-A, had no effect on myotube differentiation rate, suggesting that STARS regulates differentiation via a MRTF-A independent mechanism. Conclusion: These findings position STARS as an important regulator of skeletal muscle growth and regeneration.
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Affiliation(s)
- Marita A Wallace
- Centre for Physical Activity and Nutrition Research, School of Exercise and Nutrition Sciences, Deakin University Burwood, VIC, Australia
| | - Paul A Della Gatta
- Centre for Physical Activity and Nutrition Research, School of Exercise and Nutrition Sciences, Deakin University Burwood, VIC, Australia
| | - Bilal Ahmad Mir
- Centre for Physical Activity and Nutrition Research, School of Exercise and Nutrition Sciences, Deakin University Burwood, VIC, Australia
| | - Greg M Kowalski
- Centre for Physical Activity and Nutrition Research, School of Exercise and Nutrition Sciences, Deakin University Burwood, VIC, Australia
| | - Joachim Kloehn
- Department of Biochemistry and Molecular Biology, Bio21 Institute of Molecular Science and Biotechnology, University of Melbourne Parkville, VIC, Australia
| | - Malcom J McConville
- Department of Biochemistry and Molecular Biology, Bio21 Institute of Molecular Science and Biotechnology, University of Melbourne Parkville, VIC, Australia
| | - Aaron P Russell
- Centre for Physical Activity and Nutrition Research, School of Exercise and Nutrition Sciences, Deakin University Burwood, VIC, Australia
| | - Séverine Lamon
- Centre for Physical Activity and Nutrition Research, School of Exercise and Nutrition Sciences, Deakin University Burwood, VIC, Australia
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Lamon S, Wallace MA, Russell AP. The STARS signaling pathway: a key regulator of skeletal muscle function. Pflugers Arch 2014; 466:1659-71. [DOI: 10.1007/s00424-014-1475-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2013] [Revised: 02/04/2014] [Accepted: 02/05/2014] [Indexed: 01/08/2023]
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Wallace MA, Russell AP. Striated muscle activator of Rho signaling is required for myotube survival but does not influence basal protein synthesis or degradation. Am J Physiol Cell Physiol 2013; 305:C414-26. [PMID: 23720020 DOI: 10.1152/ajpcell.00421.2012] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Skeletal muscle mass is regulated by sensing and transmitting extracellular mechanical stress signals to intracellular signaling pathways controlling protein synthesis and degradation. Striated muscle activator of Rho signaling (STARS) is a muscle-specific actin-binding protein that is sensitive to extracellular stress signals. STARS stimulates actin polymerization and influences serum response factor (SRF) and peroxisome proliferator-activated receptor-γ coactivator (PGC)-1α transcription of genes involved in muscle growth, structure, and contraction. The role of STARS in skeletal muscle cells is not well understood. This study investigated whether STARS influenced C2C12 myotube growth by regulating protein synthesis and degradation. The influence of STARS on Pgc-1α, Srf, and Errα mRNA levels, as well as several of their downstream targets involved in muscle cell growth, contraction, and metabolism, was also investigated. STARS overexpression increased actin polymerization, with no effect on protein synthesis, protein degradation, or Akt phosphorylation. STARS overexpression increased Pgc-1α, Srf, Ckmt2, Cpt-1β, and Mhc1 mRNA. STARS knockdown reduced actin polymerization and increased cell death and dead cell protease activity. It also increased markers of inflammation (Casp1, Il-1β, and Mcp-1), regeneration (Socs3 and Myh8), and fast myosin isoforms (Mhc2a and Mhc2x). We show for the first time in muscle cells that STARS overexpression increases actin polymerization and shifts the muscle cell to a more oxidative phenotype. The suppression of STARS causes cell death and increases markers of necrosis, inflammation, and regeneration. As STARS levels are suppressed in clinical models associated with increased necrosis and inflammation, such as aging and limb immobilization, rescuing STARS maybe a future therapeutic strategy to maintain skeletal muscle function and attenuate contraction-induced muscle damage.
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Affiliation(s)
- Marita A Wallace
- Centre for Physical Activity and Nutrition, School of Exercise and Nutrition Sciences, Deakin University, Burwood, Victoria, Australia
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Vissing K, Rahbek SK, Lamon S, Farup J, Stefanetti RJ, Wallace MA, Vendelbo MH, Russell A. Effect of resistance exercise contraction mode and protein supplementation on members of the STARS signalling pathway. J Physiol 2013; 591:3749-63. [PMID: 23753523 DOI: 10.1113/jphysiol.2012.249755] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
The striated muscle activator of Rho signalling (STARS) pathway is suggested to provide a link between external stress responses and transcriptional regulation in muscle. However, the sensitivity of STARS signalling to different mechanical stresses has not been investigated. In a comparative study, we examined the regulation of the STARS signalling pathway in response to unilateral resistance exercise performed as either eccentric (ECC) or concentric (CONC) contractions as well as prolonged training; with and without whey protein supplementation. Skeletal muscle STARS, myocardian-related transcription factor-A (MRTF-A) and serum response factor (SRF) mRNA and protein, as well as muscle cross-sectional area and maximal voluntary contraction, were measured. A single-bout of exercise produced increases in STARS and SRF mRNA and decreases in MRTF-A mRNA with both ECC and CONC exercise, but with an enhanced response occurring following ECC exercise. A 31% increase in STARS protein was observed exclusively after CONC exercise (P < 0.001), while pSRF protein levels increased similarly by 48% with both CONC and ECC exercise (P < 0.001). Prolonged ECC and CONC training equally stimulated muscle hypertrophy and produced increases in MRTF-A protein of 125% and 99%, respectively (P < 0.001). No changes occurred for total SRF protein. There was no effect of whey protein supplementation. These results show that resistance exercise provides an acute stimulation of the STARS pathway that is contraction mode dependent. The responses to acute exercise were more pronounced than responses to accumulated training, suggesting that STARS signalling is primarily involved in the initial phase of exercise-induced muscle adaptations.
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Affiliation(s)
- Kristian Vissing
- Section of Sport Science, Department of Public Health, Aarhus University, Dalgas Avenue 4, DK-8000 Aarhus C, Denmark.
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Lamon S, Wallace MA, Stefanetti RJ, Rahbek SK, Vendelbo MH, Russell AP, Vissing K. Regulation of the STARS signaling pathway in response to endurance and resistance exercise and training. Pflugers Arch 2013; 465:1317-25. [DOI: 10.1007/s00424-013-1265-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2013] [Revised: 03/07/2013] [Accepted: 03/08/2013] [Indexed: 11/27/2022]
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Wallace MA, Lamon S, Russell AP. The regulation and function of the striated muscle activator of rho signaling (STARS) protein. Front Physiol 2012; 3:469. [PMID: 23248604 PMCID: PMC3520124 DOI: 10.3389/fphys.2012.00469] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2012] [Accepted: 11/28/2012] [Indexed: 11/15/2022] Open
Abstract
Healthy living throughout the lifespan requires continual growth and repair of cardiac, smooth, and skeletal muscle. To effectively maintain these processes muscle cells detect extracellular stress signals and efficiently transmit them to activate appropriate intracellular transcriptional programs. The striated muscle activator of Rho signaling (STARS) protein, also known as Myocyte Stress-1 (MS1) protein and Actin-binding Rho-activating protein (ABRA) is highly enriched in cardiac, skeletal, and smooth muscle. STARS binds actin, co-localizes to the sarcomere and is able to stabilize the actin cytoskeleton. By regulating actin polymerization, STARS also controls an intracellular signaling cascade that stimulates the serum response factor (SRF) transcriptional pathway; a pathway controlling genes involved in muscle cell proliferation, differentiation, and growth. Understanding the activation, transcriptional control and biological roles of STARS in cardiac, smooth, and skeletal muscle, will improve our understanding of physiological and pathophysiological muscle development and function.
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Affiliation(s)
- Marita A Wallace
- Centre for Physical Activity and Nutrition Research, School of Exercise and Nutrition Sciences, Deakin University Burwood, VIC, Australia
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Cardiac expression of ms1/STARS, a novel gene involved in cardiac development and disease, is regulated by GATA4. Mol Cell Biol 2012; 32:1830-43. [PMID: 22431517 DOI: 10.1128/mcb.06374-11] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Ms1/STARS is a novel muscle-specific actin-binding protein that specifically modulates the myocardin-related transcription factor (MRTF)-serum response factor (SRF) regulatory axis within striated muscle. This ms1/STARS-dependent regulatory axis is of central importance within the cardiac gene regulatory network and has been implicated in cardiac development and postnatal cardiac function/homeostasis. The dysregulation of ms1/STARS is associated with and causative of pathological cardiac phenotypes, including cardiac hypertrophy and cardiomyopathy. In order to gain an understanding of the mechanisms governing ms1/STARS expression in the heart, we have coupled a comparative genomic in silico analysis with reporter, gain-of-function, and loss-of-function approaches. Through this integrated analysis, we have identified three evolutionarily conserved regions (ECRs), α, SINA, and DINA, that act as cis-regulatory modules and confer differential cardiac cell-specific activity. Two of these ECRs, α and DINA, displayed distinct regulatory sensitivity to the core cardiac transcription factor GATA4. Overall, our results demonstrate that within embryonic, neonatal, and adult hearts, GATA4 represses ms1/STARS expression with the pathologically associated depletion of GATA4 (type 1/type 2 diabetic models), resulting in ms1/STARS upregulation. This GATA4-dependent repression of ms1/STARS expression has major implications for MRTF-SRF signaling in the context of cardiac development and disease.
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Molecular characterization of the porcine JHDM1A gene associated with average daily gain: evaluation its role in skeletal muscle development and growth. Mol Biol Rep 2010; 38:4697-704. [DOI: 10.1007/s11033-010-0604-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2010] [Accepted: 11/23/2010] [Indexed: 01/09/2023]
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Liu C, Gao H, Zhai S, Liu B. Molecular characterization, chromosomal localization, expression profile and association analysis with carcass traits of the porcine dickkopf homolog1 gene. Mol Biol Rep 2010; 38:1929-34. [DOI: 10.1007/s11033-010-0313-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2010] [Accepted: 09/03/2010] [Indexed: 11/28/2022]
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