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Ebert SM, Al-Zougbi A, Bodine SC, Adams CM. Skeletal Muscle Atrophy: Discovery of Mechanisms and Potential Therapies. Physiology (Bethesda) 2020; 34:232-239. [PMID: 31165685 DOI: 10.1152/physiol.00003.2019] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Skeletal muscle atrophy proceeds through a complex molecular signaling network that is just beginning to be understood. Here, we discuss examples of recently identified molecular mechanisms of muscle atrophy and how they highlight an immense need and opportunity for focused biochemical investigations and further unbiased discovery work.
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Affiliation(s)
- Scott M Ebert
- Departments of Internal Medicine and Molecular Physiology and Biophysics, and the Fraternal Order of Eagles Diabetes Research Center, Roy J. and Lucille A. Carver College of Medicine, The University of Iowa , Iowa City, Iowa.,Emmyon, Inc., Coralville, Iowa
| | - Asma Al-Zougbi
- Departments of Internal Medicine and Molecular Physiology and Biophysics, and the Fraternal Order of Eagles Diabetes Research Center, Roy J. and Lucille A. Carver College of Medicine, The University of Iowa , Iowa City, Iowa
| | - Sue C Bodine
- Departments of Internal Medicine and Molecular Physiology and Biophysics, and the Fraternal Order of Eagles Diabetes Research Center, Roy J. and Lucille A. Carver College of Medicine, The University of Iowa , Iowa City, Iowa.,Emmyon, Inc., Coralville, Iowa
| | - Christopher M Adams
- Departments of Internal Medicine and Molecular Physiology and Biophysics, and the Fraternal Order of Eagles Diabetes Research Center, Roy J. and Lucille A. Carver College of Medicine, The University of Iowa , Iowa City, Iowa.,Emmyon, Inc., Coralville, Iowa.,Iowa City Veterans Affairs Medical Center, Iowa City, Iowa
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52
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Hammers DW, Hart CC, Patsalos A, Matheny MK, Wright LA, Nagy L, Sweeney HL. Glucocorticoids counteract hypertrophic effects of myostatin inhibition in dystrophic muscle. JCI Insight 2020; 5:133276. [PMID: 31830002 PMCID: PMC7030817 DOI: 10.1172/jci.insight.133276] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Accepted: 12/04/2019] [Indexed: 12/25/2022] Open
Abstract
Duchenne muscular dystrophy (DMD) is a devastating genetic muscle disease resulting in progressive muscle degeneration and wasting. Glucocorticoids, specifically prednisone/prednisolone and deflazacort, are commonly used by DMD patients. Emerging DMD therapeutics include those targeting the muscle-wasting factor, myostatin (Mstn). The aim of this study was to investigate how chronic glucocorticoid treatment impacts the efficacy of Mstn inhibition in the D2.mdx mouse model of DMD. We report that chronic treatment of dystrophic mice with prednisolone (Pred) causes significant muscle wasting, entailing both activation of the ubiquitin-proteasome degradation pathway and inhibition of muscle protein synthesis. Combining Pred with Mstn inhibition, using a modified Mstn propeptide (dnMstn), completely abrogates the muscle hypertrophic effects of Mstn inhibition independently of Mstn expression or SMAD3 activation. Transcriptomic analysis identified that combining Pred with dnMstn treatment affects gene expression profiles associated with inflammation, metabolism, and fibrosis. Additionally, we demonstrate that Pred-induced muscle atrophy is not prevented by Mstn ablation. Therefore, glucocorticoids interfere with potential muscle mass benefits associated with targeting Mstn, and the ramifications of glucocorticoid use should be a consideration during clinical trial design for DMD therapeutics. These results have significant implications for past and future Mstn inhibition trials in DMD.
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Affiliation(s)
- David W. Hammers
- Department of Pharmacology and Therapeutics and
- Myology Institute, University of Florida College of Medicine, Gainesville, Florida, USA
| | - Cora C. Hart
- Department of Pharmacology and Therapeutics and
- Myology Institute, University of Florida College of Medicine, Gainesville, Florida, USA
| | - Andreas Patsalos
- Department of Medicine and
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
- Johns Hopkins All Children’s Hospital, St. Petersburg, Florida, USA
| | - Michael K. Matheny
- Department of Pharmacology and Therapeutics and
- Myology Institute, University of Florida College of Medicine, Gainesville, Florida, USA
| | - Lillian A. Wright
- Department of Pharmacology and Therapeutics and
- Myology Institute, University of Florida College of Medicine, Gainesville, Florida, USA
| | - Laszlo Nagy
- Department of Medicine and
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
- Johns Hopkins All Children’s Hospital, St. Petersburg, Florida, USA
| | - H. Lee Sweeney
- Department of Pharmacology and Therapeutics and
- Myology Institute, University of Florida College of Medicine, Gainesville, Florida, USA
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Kappa-on-Heavy (KoH) bodies are a distinct class of fully-human antibody-like therapeutic agents with antigen-binding properties. Proc Natl Acad Sci U S A 2019; 117:292-299. [PMID: 31879340 DOI: 10.1073/pnas.1901734117] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
We describe a Kappa-on-Heavy (KoH) mouse that produces a class of highly diverse, fully human, antibody-like agents. This mouse was made by replacing the germline variable sequences of both the Ig heavy-chain (IgH) and Ig kappa (IgK) loci with the human IgK germline variable sequences, producing antibody-like molecules with an antigen binding site made up of 2 kappa variable domains. These molecules, named KoH bodies, structurally mimic naturally existing Bence-Jones light-chain dimers in their variable domains and remain wild-type in their antibody constant domains. Unlike artificially diversified, nonimmunoglobulin alternative scaffolds (e.g., DARPins), KoH bodies consist of a configuration of normal Ig scaffolds that undergo natural diversification in B cells. Monoclonal KoH bodies have properties similar to those of conventional antibodies but exhibit an enhanced ability to bind small molecules such as the endogenous cardiotonic steroid marinobufagenin (MBG) and nicotine. A comparison of crystal structures of MBG bound to a KoH Fab versus a conventional Fab showed that the KoH body has a much deeper binding pocket, allowing MBG to be held 4 Å further down into the combining site between the 2 variable domains.
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54
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Gan M, Shen L, Liu L, Guo Z, Wang S, Chen L, Zheng T, Fan Y, Tan Y, Jiang D, Li X, Zhang S, Zhu L. miR-222 is involved in the regulation of genistein on skeletal muscle fiber type. J Nutr Biochem 2019; 80:108320. [PMID: 32361609 DOI: 10.1016/j.jnutbio.2019.108320] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Revised: 10/05/2019] [Accepted: 11/27/2019] [Indexed: 12/18/2022]
Abstract
In skeletal muscle, the composition of the fiber types has a profound impact on athletic performance, such as endurance or strength output. The proportions of muscle fiber types have also been associated with certain diseases, including dyskinesia, obesity and insulin resistance. Genistein, a natural estrogen, has been demonstrated to regulate fatty acid oxidation and insulin sensitivity in skeletal muscle. However, it is unknown whether genistein can regulate skeletal muscle fiber types. Furthermore, the mechanism of its effect on skeletal muscle energy metabolism is not entirely clear. In this study, in vivo and in vitro experiments were used to explore the effect of genistein on the muscle fiber-type transitions and muscle metabolism. The results indicated that genistein not only promotes skeletal muscle development but increases the expression of slow muscle fibers in mice as well. It was also demonstrated that genistein altered the ratios of fiber type and promoted mitochondrial biogenesis in C2C12 myoblasts. Interestingly, the expression of miR-222 was decreased by genistein, and it was demonstrated that this microRNA targets the PGC1α gene. In C2C12 myoblasts, miR-222 appears to regulate fiber type conversion and mitochondrial biogenesis. However, this function was significantly reduced following genistein treatment. These results suggest that miR-222 may be involved in the regulation of genistein on skeletal muscle fiber and muscle metabolism, and genistein may be used to improve muscle health.
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Affiliation(s)
- Mailin Gan
- College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, Sichuan, 611130, China; Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu, Sichuan, 611130, China
| | - Linyuan Shen
- College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, Sichuan, 611130, China; Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu, Sichuan, 611130, China
| | - Lin Liu
- College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, Sichuan, 611130, China; Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu, Sichuan, 611130, China
| | - Zhixian Guo
- College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, Sichuan, 611130, China; Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu, Sichuan, 611130, China
| | - Shujie Wang
- College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, Sichuan, 611130, China; Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu, Sichuan, 611130, China
| | - Lei Chen
- College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, Sichuan, 611130, China; Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu, Sichuan, 611130, China
| | - Ting Zheng
- College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, Sichuan, 611130, China; Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu, Sichuan, 611130, China
| | - Yuan Fan
- College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, Sichuan, 611130, China; Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu, Sichuan, 611130, China
| | - Ya Tan
- College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, Sichuan, 611130, China; Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu, Sichuan, 611130, China
| | - Dongmei Jiang
- College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, Sichuan, 611130, China; Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu, Sichuan, 611130, China
| | - Xuewei Li
- College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, Sichuan, 611130, China; Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu, Sichuan, 611130, China
| | - Shunhua Zhang
- College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, Sichuan, 611130, China; Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu, Sichuan, 611130, China.
| | - Li Zhu
- College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, Sichuan, 611130, China; Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu, Sichuan, 611130, China.
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Tan KT, Ang STJ, Tsai SY. Sarcopenia: Tilting the Balance of Protein Homeostasis. Proteomics 2019; 20:e1800411. [PMID: 31722440 DOI: 10.1002/pmic.201800411] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Revised: 11/04/2019] [Indexed: 12/14/2022]
Abstract
Sarcopenia, defined as age-associated decline of muscle mass and function, is a risk factor for mortality and disability, and comorbid with several chronic diseases such as type II diabetes and cardiovascular diseases. Clinical trials showed that nutritional supplements had positive effects on muscle mass, but not on muscle function and strength, demonstrating our limited understanding of the molecular events involved in the ageing muscle. Protein homeostasis, the equilibrium between protein synthesis and degradation, is proposed as the major mechanism underlying the development of sarcopenia. As the key central regulator of protein homeostasis, the mammalian target of rapamycin (mTOR) is proposed to be essential for muscle hypertrophy. Paradoxically, sustained activation of mTOR complex 1 (mTORC1) is associated with a loss of sensitivity to extracellular signaling in the elderly. It is not understood why sustained mTORC1 activity, which should induce muscle hypertrophy, instead results in muscle atrophy. Here, recent findings on the implications of disrupting protein homeostasis on muscle physiology and sarcopenia development in the context of mTOR/protein kinase B (AKT) signaling are reviewed. Understanding the role of these molecular mechanisms during the ageing process will contribute towards the development of targeted therapies that will improve protein metabolism and reduce sarcopenia.
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Affiliation(s)
- Kuan Ting Tan
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, 2 Medical Drive, MD9 Admin Office, Singapore, 117597, Singapore
| | - Seok-Ting Jamie Ang
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, 2 Medical Drive, MD9 Admin Office, Singapore, 117597, Singapore
| | - Shih-Yin Tsai
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, 2 Medical Drive, MD9 Admin Office, Singapore, 117597, Singapore
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56
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Tavoian D, Arnold WD, Mort SC, de Lacalle S. Sex differences in body composition but not neuromuscular function following long-term, doxycycline-induced reduction in circulating levels of myostatin in mice. PLoS One 2019; 14:e0225283. [PMID: 31751423 PMCID: PMC6872155 DOI: 10.1371/journal.pone.0225283] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Accepted: 10/31/2019] [Indexed: 02/05/2023] Open
Abstract
Age-related declines in muscle function result from changes in muscle structure and contractile properties, as well as from neural adaptations. Blocking myostatin to drive muscle growth is one potential therapeutic approach. While the effects of myostatin depletion on muscle characteristics are well established, we have very little understanding of its effects on the neural system. Here we assess the effects of long-term, post-developmental myostatin reduction on electrophysiological motor unit characteristics and body composition in aging mice. We used male (N = 21) and female (N = 26) mice containing a tetracycline-inducible system to delete the myostatin gene in skeletal muscle. Starting at 12 months of age, half of the mice were administered doxycycline (tetracycline) through their chow for one year. During that time we measured food intake, body composition, and hindlimb electromyographic responses. Doxycycline-induced myostatin reduction had no effect on motor unit properties for either sex, though significant age-dependent declines in motor unit number occurred in all mice. However, treatment with doxycycline induced different changes in body composition between sexes. All female mice increased in total, lean and fat mass, but doxycycline-treated female mice experienced a significantly larger increase in lean mass than controls. All male mice also increased total and lean mass, but administration of doxycycline had no effect. Additionally, doxycycline-treated male mice maintained their fat mass at baseline levels, while the control group experienced a significant increase from baseline and compared to the doxycycline treated group. Our results show that long-term administration of doxycycline results in body composition adaptations that are distinctive between male and female mice, and that the effects of myostatin reduction are most pronounced during the first three months of treatment. We also report that age-related changes in motor unit number are not offset by reduced myostatin levels, despite increased lean mass exhibited by female mice.
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Affiliation(s)
- Dallin Tavoian
- Program in Translational Biomedical Sciences, 1 Ohio University, Athens, OH, United States of America
| | - W. David Arnold
- Departments of Neurology, PM&R, and Neuroscience, and Physiology and Cell Biology, The Ohio State University, Columbus, OH, United States of America
| | - Sophia C. Mort
- Program in Translational Biomedical Sciences, 1 Ohio University, Athens, OH, United States of America
| | - Sonsoles de Lacalle
- Sonsoles de Lacalle, Department of Biomedical Sciences,1 Ohio University, Athens, OH, United States of America
- * E-mail:
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57
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Rovira Gonzalez YI, Moyer AL, LeTexier NJ, Bratti AD, Feng S, Sun C, Liu T, Mula J, Jha P, Iyer SR, Lovering R, O’Rourke B, Noh HL, Suk S, Kim JK, Essien Umanah GK, Wagner KR. Mss51 deletion enhances muscle metabolism and glucose homeostasis in mice. JCI Insight 2019; 4:122247. [PMID: 31527314 PMCID: PMC6824300 DOI: 10.1172/jci.insight.122247] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Accepted: 09/11/2019] [Indexed: 12/16/2022] Open
Abstract
Myostatin is a negative regulator of muscle growth and metabolism and its inhibition in mice improves insulin sensitivity, increases glucose uptake into skeletal muscle, and decreases total body fat. A recently described mammalian protein called MSS51 is significantly downregulated with myostatin inhibition. In vitro disruption of Mss51 results in increased levels of ATP, β-oxidation, glycolysis, and oxidative phosphorylation. To determine the in vivo biological function of Mss51 in mice, we disrupted the Mss51 gene by CRISPR/Cas9 and found that Mss51-KO mice have normal muscle weights and fiber-type distribution but reduced fat pads. Myofibers isolated from Mss51-KO mice showed an increased oxygen consumption rate compared with WT controls, indicating an accelerated rate of skeletal muscle metabolism. The expression of genes related to oxidative phosphorylation and fatty acid β-oxidation were enhanced in skeletal muscle of Mss51-KO mice compared with that of WT mice. We found that mice lacking Mss51 and challenged with a high-fat diet were resistant to diet-induced weight gain, had increased whole-body glucose turnover and glycolysis rate, and increased systemic insulin sensitivity and fatty acid β-oxidation. These findings demonstrate that MSS51 modulates skeletal muscle mitochondrial respiration and regulates whole-body glucose and fatty acid metabolism, making it a potential target for obesity and diabetes.
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Affiliation(s)
- Yazmin I. Rovira Gonzalez
- The Hugo W. Moser Research Institute, Kennedy Krieger Institute, Baltimore, Maryland, USA
- Cellular and Molecular Medicine Graduate Program
| | - Adam L. Moyer
- The Hugo W. Moser Research Institute, Kennedy Krieger Institute, Baltimore, Maryland, USA
- Cellular and Molecular Medicine Graduate Program
| | - Nicolas J. LeTexier
- The Hugo W. Moser Research Institute, Kennedy Krieger Institute, Baltimore, Maryland, USA
| | - August D. Bratti
- The Hugo W. Moser Research Institute, Kennedy Krieger Institute, Baltimore, Maryland, USA
| | - Siyuan Feng
- The Hugo W. Moser Research Institute, Kennedy Krieger Institute, Baltimore, Maryland, USA
| | - Congshan Sun
- The Hugo W. Moser Research Institute, Kennedy Krieger Institute, Baltimore, Maryland, USA
- Department of Neurology
- Department of Neuroscience, and
| | - Ting Liu
- Division of Cardiology, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
| | - Jyothi Mula
- The Hugo W. Moser Research Institute, Kennedy Krieger Institute, Baltimore, Maryland, USA
| | - Pankhuri Jha
- The Hugo W. Moser Research Institute, Kennedy Krieger Institute, Baltimore, Maryland, USA
| | - Shama R. Iyer
- Department of Orthopaedics, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Richard Lovering
- Department of Orthopaedics, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Brian O’Rourke
- Division of Cardiology, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
| | - Hye Lim Noh
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Sujin Suk
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Jason K. Kim
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, USA
- Division of Endocrinology, Metabolism and Diabetes, Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | | | - Kathryn R. Wagner
- The Hugo W. Moser Research Institute, Kennedy Krieger Institute, Baltimore, Maryland, USA
- Department of Neurology
- Department of Neuroscience, and
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Exogenous Expression of an Alternative Splicing Variant of Myostatin Prompts Leg Muscle Fiber Hyperplasia in Japanese Quail. Int J Mol Sci 2019; 20:ijms20184617. [PMID: 31540432 PMCID: PMC6770055 DOI: 10.3390/ijms20184617] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2019] [Revised: 09/04/2019] [Accepted: 09/17/2019] [Indexed: 12/03/2022] Open
Abstract
Myostatin (MSTN) negatively regulates muscle growth and development through inhibiting myoblast proliferation and differentiation. Five alternative splicing isoforms of MSTN (MSTN-A to MSTN-E) have been discovered in domestic avian species. MSTN-A has high expression in skeletal muscle and encodes the full-length peptide with anti-myogenic activity. Another isoform, MSTN-B, is also highly expressed in skeletal muscle and encodes a truncated peptide that has pro-myogenic capabilities in vitro, which include promoting the proliferation and differentiation of quail muscle precursor cells. The objective of this study was to investigate overexpression of MSTN-B in vivo by using two independent lines of transgenic Japanese quail with expression directed in the skeletal muscle. Unexpectedly, the chicken skeletal muscle alpha actin 1 (cACTA1) promoter resulted in restricted exogenous MSTN-B protein expression to certain skeletal muscles, such as the gastrocnemius and tibialis anterior, but not the pectoralis major muscle. Gastrocnemius weight as a percentage of body weight in transgenic quail was increased compared to non-transgenic quail at posthatch day 21 (D21) and posthatch D42. An increase in the size of the gastrocnemius in transgenic quail was attributed to an increase in fiber number but not fiber cross-sectional area (CSA). During embryonic development, paired box 7 (PAX7) expression was prolonged in the transgenic embryos, but other myogenic regulatory factors (MRFs) were unchanged after MSTN-B overexpression. Taken together, these data provide novel insights into the regulation of skeletal muscle development by alternative splicing mechanisms in avians.
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59
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Okamoto H, Taniguchi A, Usami S, Taguchi A, Takayama K, Hayashi Y. Inactivation of myostatin by photo-oxygenation using catalyst-functionalized peptides. Chem Commun (Camb) 2019; 55:9108-9111. [PMID: 31298230 DOI: 10.1039/c9cc04368c] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Inhibition of myostatin is an attractive treatment for muscular dystrophy and other amyotrophic diseases. A myostatin-binding peptide was functionalized by equipped with an on/off switchable photo-oxygenation catalyst. This peptide induces a selective oxygenation of myostatin under near-infrared light, resulting in inactivation of myostatin. This peptide shows several orders of magnitude greater inhibitory effect than the original peptide.
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Affiliation(s)
- Hideyuki Okamoto
- Department of Medicinal Chemistry, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, Tokyo 192-0392, Japan.
| | - Atsuhiko Taniguchi
- Department of Medicinal Chemistry, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, Tokyo 192-0392, Japan.
| | - Shoya Usami
- Department of Medicinal Chemistry, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, Tokyo 192-0392, Japan.
| | - Akihiro Taguchi
- Department of Medicinal Chemistry, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, Tokyo 192-0392, Japan.
| | - Kentaro Takayama
- Department of Medicinal Chemistry, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, Tokyo 192-0392, Japan.
| | - Yoshio Hayashi
- Department of Medicinal Chemistry, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, Tokyo 192-0392, Japan.
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Cote SM, Jackson J, Pirruccello-Straub M, Carven GJ, Wawersik S. A Sensitive and Selective Immunoassay for the Quantitation of Serum Latent Myostatin after In Vivo Administration of SRK-015, a Selective Inhibitor of Myostatin Activation. SLAS DISCOVERY 2019; 25:95-103. [PMID: 31347449 PMCID: PMC6927069 DOI: 10.1177/2472555219860779] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Myostatin, a member of the transforming growth factor β (TGFβ) superfamily, is a key regulator of skeletal muscle mass and a therapeutic target for muscle wasting diseases. We developed a human monoclonal antibody, SRK-015, that selectively binds to and inhibits proteolytic processing of myostatin precursors, thereby preventing growth factor release from the latent complex. As a consequence of antibody binding, latent myostatin accumulates in the circulation of animals treated with SRK-015 or closely related antibodies, suggesting that quantitation of latent myostatin in serum may serve as a biomarker for target engagement. To accurately measure SRK-015 target engagement, we developed a sensitive plate-based electrochemiluminescent immunoassay to quantitate latent myostatin in serum samples. The assay selectively recognizes latent myostatin without cross-reactivity to promyostatin, mature myostatin, or closely related members of the TGFβ superfamily. To enable use of the assay in samples from animals dosed with SRK-015, we incorporated a low-pH step that dissociates SRK-015 from latent myostatin, improving drug tolerance of the assay. The assay meets inter- and intra-assay accuracy and precision acceptance criteria, and it has a lower limit of quantitation (LLOQ) of 10 ng/mL. We then tested serum samples from a pharmacology study in cynomolgus monkeys treated with SRK-015. Serum latent myostatin increases after treatment with SRK-015, reaches a dose-dependent plateau approximately 20 days after dosing, and trends back toward baseline after cessation of antibody dosing. Taken together, these data suggest that this assay can be used to accurately measure levels of the primary circulating form of myostatin in population-based or pharmacodynamic studies.
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61
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Abstract
Introduction: Sarcopenia, the age-related loss of skeletal muscle mass and function, is a global health problem that contributes to the development of physical disability, morbidity and mortality in the ageing population. Sarcopenia is now recognised in many countries as a muscle disease with an ICD-10-CM Diagnosis Code for billing care related to this condition, despite no FDA-approved treatments being currently available. Areas covered: This review highlights the current state of knowledge regarding the biological mechanisms contributing to the age-related loss of muscle mass and function and provides a summary of existing and emerging pharmacotherapies in clinical trials for sarcopenia. Expert opinion: While understanding of the pathophysiology of sarcopenia has progressed, rigorous preclinical studies that better inform clinical trials are needed to accelerate drug discovery and identify safe and effective treatments. Few drugs have been developed specifically for sarcopenia and many have failed to meet clinically relevant outcomes related to strength and physical performance. The multifactorial complexity of sarcopenia means that tailored, personalised treatments are more likely to be required than just a single intervention.
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Affiliation(s)
- Justin P Hardee
- Centre for Muscle Research, Department of Physiology, The University of Melbourne , Melbourne , Victoria , Australia
| | - Gordon S Lynch
- Centre for Muscle Research, Department of Physiology, The University of Melbourne , Melbourne , Victoria , Australia
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62
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Long KK, O’Shea KM, Khairallah RJ, Howell K, Paushkin S, Chen KS, Cote SM, Webster MT, Stains JP, Treece E, Buckler A, Donovan A. Specific inhibition of myostatin activation is beneficial in mouse models of SMA therapy. Hum Mol Genet 2019; 28:1076-1089. [PMID: 30481286 PMCID: PMC6423420 DOI: 10.1093/hmg/ddy382] [Citation(s) in RCA: 71] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Revised: 10/29/2018] [Accepted: 10/31/2018] [Indexed: 12/22/2022] Open
Abstract
Spinal muscular atrophy (SMA) is a neuromuscular disease characterized by loss of α-motor neurons, leading to profound skeletal muscle atrophy. Patients also suffer from decreased bone mineral density and increased fracture risk. The majority of treatments for SMA, approved or in clinic trials, focus on addressing the underlying cause of disease, insufficient production of full-length SMN protein. While restoration of SMN has resulted in improvements in functional measures, significant deficits remain in both mice and SMA patients following treatment. Motor function in SMA patients may be additionally improved by targeting skeletal muscle to reduce atrophy and improve muscle strength. Inhibition of myostatin, a negative regulator of muscle mass, offers a promising approach to increase muscle function in SMA patients. Here we demonstrate that muSRK-015P, a monoclonal antibody which specifically inhibits myostatin activation, effectively increases muscle mass and function in two variants of the pharmacological mouse model of SMA in which pharmacologic restoration of SMN has taken place either 1 or 24 days after birth to reflect early or later therapeutic intervention. Additionally, muSRK-015P treatment improves the cortical and trabecular bone phenotypes in these mice. These data indicate that preventing myostatin activation has therapeutic potential in addressing muscle and bone deficiencies in SMA patients. An optimized variant of SRK-015P, SRK-015, is currently in clinical development for treatment of SMA.
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Affiliation(s)
| | | | | | - Kelly Howell
- SMA Foundation, 888 7th Avenue #400, New York, NY
| | | | - Karen S Chen
- SMA Foundation, 888 7th Avenue #400, New York, NY
| | - Shaun M Cote
- Scholar Rock Inc., 620 Memorial Drive, Cambridge, MA
| | | | - Joseph P Stains
- Department of Orthopedics, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Erin Treece
- Scholar Rock Inc., 620 Memorial Drive, Cambridge, MA
| | - Alan Buckler
- Scholar Rock Inc., 620 Memorial Drive, Cambridge, MA
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63
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Guru Vishnu P, Bhattacharya TK, Bhushan B, Kumar P, Chatterjee RN, Paswan C, Dushyanth K, Divya D, Prasad AR. In silico prediction of short hairpin RNA and in vitro silencing of activin receptor type IIB in chicken embryo fibroblasts by RNA interference. Mol Biol Rep 2019; 46:2947-2959. [PMID: 30879273 DOI: 10.1007/s11033-019-04756-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2019] [Accepted: 03/08/2019] [Indexed: 12/26/2022]
Abstract
Gene silencing by RNA interference is extensively used reverse genetic approach to analyse the implications of any gene in mammalian systems. The silencing of the Activin type IIB receptor belonging to transforming growth factor beta superfamily has demonstrated increase in muscle growth in many species. We designed five short hairpin RNA constructs targeting coding region of chicken ACTRIIB. All the shRNAs were transfected into chicken embryo fibroblast cells and evaluated their silencing efficiency by real time PCR and western blotting. Initially the computational analysis of target region and shRNA constructs was undertaken to predict sequence based features (secondary structures, GC% and H-b index) and thermodynamic features (ΔGoverall, ΔGduplex, ΔGbreak-target, ΔGintra-oligomer, ΔGinter-oligomer and ΔΔGends). We determined that all these predicted features were associated with shRNA efficacy. The invitro analysis of shRNA constructs exhibited significant (P < 0.05) reduction in the levels of ACTRIIB at mRNA and protein level. The knock down efficiency of shRNAs varied significantly (P < 0.001) from 83% (shRNA 1) to 43% (shRNA 5). All the shRNAs up regulated the myogenic pathway associated genes (MyoD and MyoG) significantly (P < 0.05). There was significant (P < 0.05) up-regulation of IFNA, IFNB and MHCII transcripts. The ACTRIIB expression was inversely associated with the expression of myogenic pathway and immune response genes. The anti ACTRIIB shRNA construct 1 and 3 exhibited maximum knock down efficiency with minimal interferon response, and can be used for generating ACTRIIB knockdown chicken with higher muscle mass.
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Affiliation(s)
- P Guru Vishnu
- Sri Venkateswara Veterinary University, Tirupathi, A.P., India.
| | | | - Bharat Bhushan
- Division of Animal Genetics & Breeding, Indian Veterinary Research Institute, Izatnagar, U.P., India
| | - Pushpendra Kumar
- Division of Animal Genetics & Breeding, Indian Veterinary Research Institute, Izatnagar, U.P., India
| | | | | | - K Dushyanth
- ICAR-Directorate of Poultry Research, Hyderabad, India
| | - D Divya
- ICAR-Directorate of Poultry Research, Hyderabad, India
| | - A Rajendra Prasad
- Division of Animal Genetics & Breeding, Indian Veterinary Research Institute, Izatnagar, U.P., India
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64
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Lodberg A, van der Eerden BCJ, Boers-Sijmons B, Thomsen JS, Brüel A, van Leeuwen JPTM, Eijken M. A follistatin-based molecule increases muscle and bone mass without affecting the red blood cell count in mice. FASEB J 2019; 33:6001-6010. [PMID: 30759349 DOI: 10.1096/fj.201801969rr] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Inhibitors of the activin receptor signaling pathway (IASPs) have become candidate therapeutics for sarcopenia and bone remodeling disorders because of their ability to increase muscle and bone mass. However, IASPs utilizing activin type IIA and IIB receptors are also potent stimulators of erythropoiesis, a feature that may restrict their usage to anemic patients because of increased risk of venous thromboembolism. Based on the endogenous TGF-β superfamily antagonist follistatin (FST), a molecule in the IASP class, FSTΔHBS-mFc, was generated and tested in both ovariectomized and naive BALB/c and C57BL/6 mice. In ovariectomized mice, FSTΔHBS-mFc therapy dose-dependently increased cancellous bone mass up to 42% and improved bone microstructural indices. For the highest dosage of FSTΔHBS-mFc (30 mg/kg, 2 times/wk), the increase in cancellous bone mass was similar to that observed with parathyroid hormone therapy (1-34, 80 µg/kg, 5 times/wk). Musculus quadriceps femoris mass dose-dependently increased up to 21% in ovariectomized mice. In both ovariectomized and naive mice, FSTΔHBS-mFc therapy did not influence red blood cell count or hematocrit or hemoglobin levels. If the results are reproduced, a human FSTΔHBS-mFc version could be applicable in patients with musculoskeletal conditions irrespective of hematocrit status.-Lodberg, A., van der Eerden, B. C. J., Boers-Sijmons, B., Thomsen, J. S., Brüel, A., van Leeuwen, J. P. T. M., Eijken, M. A follistatin-based molecule increases muscle and bone mass without affecting the red blood cell count in mice.
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Affiliation(s)
- Andreas Lodberg
- Department of Pulmonary Medicine, Aarhus University Hospital, Aarhus, Denmark.,Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | | | - Bianca Boers-Sijmons
- Department of Internal Medicine, Erasmus Medical Center, Rotterdam, The Netherlands
| | | | - Annemarie Brüel
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | | | - Marco Eijken
- Department of Renal Medicine, Aarhus University Hospital, Aarhus, Denmark.,Department of Clinical Immunology, Aarhus University Hospital, Aarhus, Denmark
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65
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Otsuka Y, Egawa K, Kanzaki N, Izumo T, Rogi T, Shibata H. Quercetin glycosides prevent dexamethasone-induced muscle atrophy in mice. Biochem Biophys Rep 2019; 18:100618. [PMID: 30805562 PMCID: PMC6372881 DOI: 10.1016/j.bbrep.2019.100618] [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: 09/26/2018] [Revised: 01/26/2019] [Accepted: 01/30/2019] [Indexed: 02/04/2023] Open
Abstract
Although quercetin has numerous biological benefits, including preventing muscle atrophy due to disuse, no reports have been published to date about the preventive effects and molecular mechanisms underlying drug-induced muscle atrophy. Highly soluble and bioavailable quercetin glycosides (QGs) were used to examine the inhibition of dexamethasone (DEX)-induced muscle atrophy in vivo. Male BALB/cCrSlc mice were treated with or without QGs for 7 days ad libitum, followed by addition of DEX to their drinking water for a further 7 days. The weight of gastrocnemius (GM) adjusted by body weight was significantly decreased on day 7 after DEX treatment. DEX-induced decrease of GM weight was improved by QG co-administration on day 7. The mRNA levels of muscle atrophy-related genes in the gastrocnemius were significantly lowered by QGs on day 1. In particular, the expression of myostatin, a master regulator of muscle mass homeostasis, was suppressed to that of the control level. In murine C2C12 myotubes, quercetin elevated the phosphorylation of Akt, which are downstream of the myostatin pathway, as well as expression of atrogenes. We demonstrated the protective effect of QGs in DEX-induced muscle atrophy, which might depend on the suppression of myostatin signaling.
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Affiliation(s)
- Yuta Otsuka
- Institute for Health Care Science, Suntory Wellness Ltd, 8-1-1 Seikadai, Seika-cho, Soraku-gun, Kyoto, 619-0284, Japan
| | - Kahori Egawa
- Institute for Health Care Science, Suntory Wellness Ltd, 8-1-1 Seikadai, Seika-cho, Soraku-gun, Kyoto, 619-0284, Japan
| | - Noriyuki Kanzaki
- Institute for Health Care Science, Suntory Wellness Ltd, 8-1-1 Seikadai, Seika-cho, Soraku-gun, Kyoto, 619-0284, Japan
| | - Takayuki Izumo
- Institute for Health Care Science, Suntory Wellness Ltd, 8-1-1 Seikadai, Seika-cho, Soraku-gun, Kyoto, 619-0284, Japan
| | - Tomohiro Rogi
- Institute for Health Care Science, Suntory Wellness Ltd, 8-1-1 Seikadai, Seika-cho, Soraku-gun, Kyoto, 619-0284, Japan
| | - Hiroshi Shibata
- Institute for Health Care Science, Suntory Wellness Ltd, 8-1-1 Seikadai, Seika-cho, Soraku-gun, Kyoto, 619-0284, Japan
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66
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Rentier C, Takayama K, Saitoh M, Nakamura A, Ikeyama H, Taguchi A, Taniguchi A, Hayashi Y. Design and synthesis of potent myostatin inhibitory cyclic peptides. Bioorg Med Chem 2019; 27:1437-1443. [PMID: 30777663 DOI: 10.1016/j.bmc.2019.02.019] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2018] [Revised: 02/06/2019] [Accepted: 02/08/2019] [Indexed: 12/29/2022]
Abstract
Myostatin is a negative regulator of skeletal muscle growth and myostatin inhibitors are promising lead compounds against muscle atrophic disorders such as muscular dystrophy. Previously, we published the first report of synthetic myostatin inhibitory 23-mer peptide 1, which was identified from a myostatin precursor-derived prodomain protein. Our structure-activity relationship study afforded the potent inhibitory peptide 3. In this paper, we report an investigation of the synthesis of conformationally-constrained cyclic peptide based on the linear peptide 3. To examine the potency of side chain-to-side chain cyclized peptides, a series of disulfide-, lactam- and diester-bridged derivatives were designed and synthesized, and their myostatin inhibitory activities were evaluated. The diester-bridged peptide (11) displayed potent inhibitory activity with an in vitro IC50 value of 0.26 µM, suggesting that it could serve as a new platform for development of cyclic peptide inhibitors.
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Affiliation(s)
- Cédric Rentier
- Department of Medicinal Chemistry, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo 192-0392, Japan
| | - Kentaro Takayama
- Department of Medicinal Chemistry, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo 192-0392, Japan
| | - Mariko Saitoh
- Department of Medicinal Chemistry, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo 192-0392, Japan
| | - Akari Nakamura
- Department of Medicinal Chemistry, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo 192-0392, Japan
| | - Hiroaki Ikeyama
- Department of Medicinal Chemistry, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo 192-0392, Japan
| | - Akihiro Taguchi
- Department of Medicinal Chemistry, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo 192-0392, Japan
| | - Atsuhiko Taniguchi
- Department of Medicinal Chemistry, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo 192-0392, Japan
| | - Yoshio Hayashi
- Department of Medicinal Chemistry, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo 192-0392, Japan.
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67
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Magga J, Vainio L, Kilpiö T, Hulmi JJ, Taponen S, Lin R, Räsänen M, Szabó Z, Gao E, Rahtu-Korpela L, Alakoski T, Ulvila J, Laitinen M, Pasternack A, Koch WJ, Alitalo K, Kivelä R, Ritvos O, Kerkelä R. Systemic Blockade of ACVR2B Ligands Protects Myocardium from Acute Ischemia-Reperfusion Injury. Mol Ther 2019; 27:600-610. [PMID: 30765322 PMCID: PMC6404100 DOI: 10.1016/j.ymthe.2019.01.013] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Revised: 01/16/2019] [Accepted: 01/16/2019] [Indexed: 02/07/2023] Open
Abstract
Activin A and myostatin, members of the transforming growth factor (TGF)-β superfamily of secreted factors, are potent negative regulators of muscle growth, but their contribution to myocardial ischemia-reperfusion (IR) injury is not known. The aim of this study was to investigate if activin 2B (ACVR2B) receptor ligands contribute to myocardial IR injury. Mice were treated with soluble ACVR2B decoy receptor (ACVR2B-Fc) and subjected to myocardial ischemia followed by reperfusion for 6 or 24 h. Systemic blockade of ACVR2B ligands by ACVR2B-Fc was protective against cardiac IR injury, as evidenced by reduced infarcted area, apoptosis, and autophagy and better preserved LV systolic function following IR. ACVR2B-Fc modified cardiac metabolism, LV mitochondrial respiration, as well as cardiac phenotype toward physiological hypertrophy. Similar to its protective role in IR injury in vivo, ACVR2B-Fc antagonized SMAD2 signaling and cell death in cardiomyocytes that were subjected to hypoxic stress. ACVR2B ligand myostatin was found to exacerbate hypoxic stress. In addition to acute cardioprotection in ischemia, ACVR2B-Fc provided beneficial effects on cardiac function in prolonged cardiac stress in cardiotoxicity model. By blocking myostatin, ACVR2B-Fc potentially reduces cardiomyocyte death and modifies cardiomyocyte metabolism for hypoxic conditions to protect the heart from IR injury.
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Affiliation(s)
- Johanna Magga
- Research Unit of Biomedicine, Department of Pharmacology and Toxicology, University of Oulu, 90220 Oulu, Finland; Biocenter Oulu, University of Oulu, 90220 Oulu, Finland.
| | - Laura Vainio
- Research Unit of Biomedicine, Department of Pharmacology and Toxicology, University of Oulu, 90220 Oulu, Finland
| | - Teemu Kilpiö
- Research Unit of Biomedicine, Department of Pharmacology and Toxicology, University of Oulu, 90220 Oulu, Finland
| | - Juha J Hulmi
- Neuromuscular Research Center, Biology of Physical Activity, Faculty of Sport and Health Sciences, University of Jyväskylä, 40014 Jyväskylä, Finland; Department of Physiology, Faculty of Medicine, University of Helsinki, 00290 Helsinki, Finland
| | - Saija Taponen
- Research Unit of Biomedicine, Department of Pharmacology and Toxicology, University of Oulu, 90220 Oulu, Finland
| | - Ruizhu Lin
- Research Unit of Biomedicine, Department of Pharmacology and Toxicology, University of Oulu, 90220 Oulu, Finland; Medical Research Center Oulu, Oulu University Hospital and University of Oulu, 90220 Oulu, Finland
| | - Markus Räsänen
- Wihuri Research Institute and Translational Cancer Biology Program, Faculty of Medicine, University of Helsinki, 00290 Helsinki, Finland
| | - Zoltán Szabó
- Research Unit of Biomedicine, Department of Pharmacology and Toxicology, University of Oulu, 90220 Oulu, Finland
| | - Erhe Gao
- Center for Translational Medicine, Temple University School of Medicine, Philadelphia, PA 19140, USA
| | - Lea Rahtu-Korpela
- Research Unit of Biomedicine, Department of Pharmacology and Toxicology, University of Oulu, 90220 Oulu, Finland
| | - Tarja Alakoski
- Research Unit of Biomedicine, Department of Pharmacology and Toxicology, University of Oulu, 90220 Oulu, Finland
| | - Johanna Ulvila
- Research Unit of Biomedicine, Department of Pharmacology and Toxicology, University of Oulu, 90220 Oulu, Finland
| | - Mika Laitinen
- Department of Medicine, University of Helsinki, 00029 Helsinki, Finland; Department of Medicine, Helsinki University Hospital, 00029 Helsinki, Finland
| | - Arja Pasternack
- Department of Physiology, Faculty of Medicine, University of Helsinki, 00290 Helsinki, Finland
| | - Walter J Koch
- Center for Translational Medicine, Temple University School of Medicine, Philadelphia, PA 19140, USA
| | - Kari Alitalo
- Wihuri Research Institute and Translational Cancer Biology Program, Faculty of Medicine, University of Helsinki, 00290 Helsinki, Finland
| | - Riikka Kivelä
- Wihuri Research Institute and Translational Cancer Biology Program, Faculty of Medicine, University of Helsinki, 00290 Helsinki, Finland
| | - Olli Ritvos
- Department of Physiology, Faculty of Medicine, University of Helsinki, 00290 Helsinki, Finland
| | - Risto Kerkelä
- Research Unit of Biomedicine, Department of Pharmacology and Toxicology, University of Oulu, 90220 Oulu, Finland; Medical Research Center Oulu, Oulu University Hospital and University of Oulu, 90220 Oulu, Finland
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68
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Kim S, Choi JY, Moon S, Park DH, Kwak HB, Kang JH. Roles of myokines in exercise-induced improvement of neuropsychiatric function. Pflugers Arch 2019; 471:491-505. [PMID: 30627775 DOI: 10.1007/s00424-019-02253-8] [Citation(s) in RCA: 79] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Revised: 12/18/2018] [Accepted: 01/03/2019] [Indexed: 01/28/2023]
Abstract
Exercise is a well-known non-pharmacological intervention to improve brain functions, including cognition, memory, and motor coordination. Contraction of skeletal muscles during exercise releases humoral factors that regulate the whole-body metabolism via interaction with other non-muscle organs. Myokines are muscle-derived effectors that regulate body metabolism by autocrine, paracrine, or endocrine action and were reportedly suggested as "exercise factors" that can improve the brain function. However, several aspects remain to be elucidated, namely the specific activities of myokines related to the whole-body metabolism or brain function, the mechanisms of regulation of other organs or cells, the sources of "exercise factors" that regulate brain function, and their mechanisms of interaction with non-muscle organs. In this paper, we present the physiological functions of myokines secreted by exercise, including regulation of the whole-body metabolism by interaction with other organs and adaptation of skeletal muscles to exercise. In addition, we discuss the functions of myokines that possibly contribute to exercise-induced improvement of brain function. Among several myokines, brain-derived neurotrophic factor (BDNF) is the most studied myokine that regulates adult neurogenesis and synaptic plasticity. However, the source of circulating BDNF and its upstream effector, insulin-like growth factor (IGF-1), and irisin and the effect size of peripheral BDNF, irisin, and IGF-1 released after exercise should be further investigated. Recently, cathepsin B has been reported to be secreted from skeletal muscles and upregulate BDNF following exercise, which was associated with improved cognitive function. We reviewed the level of evidence for the effect of myokine on the brain function. Level of evidence for the association of the change in circulating myokine following exercise and improvement of neuropsychiatric function is lower than the level of evidence for the benefit of exercise on the brain. Therefore, more clinical evidences for the association of myokine release after exercise and their effect on the brain function are required. Finally, we discuss the effect size of the action of myokines on cognitive benefits of exercise, in addition to other contributors, such as improvement of the cardiovascular system or the effect of "exercise factors" released from non-muscle organs, particularly in patients with sarcopenia.
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Affiliation(s)
- Sujin Kim
- Department of Pharmacology and Hypoxia-related Disease Research Center, Inha University School of Medicine, Room 1015, 60th Anniversary Hall, 100, Inha-ro, Nam-gu, Incheon, 22212, Republic of Korea.,Department of Kinesiology, Inha University, Incheon, Republic of Korea
| | - Ji-Young Choi
- Department of Pharmacology and Hypoxia-related Disease Research Center, Inha University School of Medicine, Room 1015, 60th Anniversary Hall, 100, Inha-ro, Nam-gu, Incheon, 22212, Republic of Korea
| | - Sohee Moon
- Department of Pharmacology and Hypoxia-related Disease Research Center, Inha University School of Medicine, Room 1015, 60th Anniversary Hall, 100, Inha-ro, Nam-gu, Incheon, 22212, Republic of Korea
| | - Dong-Ho Park
- Department of Kinesiology, Inha University, Incheon, Republic of Korea
| | - Hyo-Bum Kwak
- Department of Kinesiology, Inha University, Incheon, Republic of Korea
| | - Ju-Hee Kang
- Department of Pharmacology and Hypoxia-related Disease Research Center, Inha University School of Medicine, Room 1015, 60th Anniversary Hall, 100, Inha-ro, Nam-gu, Incheon, 22212, Republic of Korea.
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69
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Iskenderian A, Liu N, Deng Q, Huang Y, Shen C, Palmieri K, Crooker R, Lundberg D, Kastrapeli N, Pescatore B, Romashko A, Dumas J, Comeau R, Norton A, Pan J, Rong H, Derakhchan K, Ehmann DE. Myostatin and activin blockade by engineered follistatin results in hypertrophy and improves dystrophic pathology in mdx mouse more than myostatin blockade alone. Skelet Muscle 2018; 8:34. [PMID: 30368252 PMCID: PMC6204036 DOI: 10.1186/s13395-018-0180-z] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2018] [Accepted: 10/14/2018] [Indexed: 01/03/2023] Open
Abstract
BACKGROUND Myostatin antagonists are being developed as therapies for Duchenne muscular dystrophy due to their strong hypertrophic effects on skeletal muscle. Engineered follistatin has the potential to combine the hypertrophy of myostatin antagonism with the anti-inflammatory and anti-fibrotic effects of activin A antagonism. METHODS Engineered follistatin was administered to C57BL/6 mice for 4 weeks, and muscle mass and myofiber size was measured. In the mdx model, engineered follistatin was dosed for 12 weeks in two studies comparing to an Fc fusion of the activin IIB receptor or an anti-myostatin antibody. Functional measurements of grip strength and tetanic force were combined with tissue analysis for markers of necrosis, inflammation, and fibrosis to evaluate improvement in dystrophic pathology. RESULTS In wild-type and mdx mice, dose-dependent increases in muscle mass and quadriceps myofiber size were observed for engineered follistatin. In mdx, increases in grip strength and tetanic force were combined with improvements in muscle markers for necrosis, inflammation, and fibrosis. Improvements in dystrophic pathology were greater for engineered follistatin than the anti-myostatin antibody. CONCLUSIONS Engineered follistatin generated hypertrophy and anti-fibrotic effects in the mdx model.
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Affiliation(s)
- Andrea Iskenderian
- Discovery Therapeutics, Shire Pharmaceuticals, Lexington, MA, USA.,Drug Discovery, Shire, Cambridge, MA, USA
| | - Nan Liu
- Discovery Therapeutics, Shire Pharmaceuticals, Lexington, MA, USA.,Drug Discovery, Shire, Cambridge, MA, USA
| | - Qingwei Deng
- Research, Shire Pharmaceuticals, Lexington, MA, 02421, USA.,Drug Discovery, Shire, Cambridge, MA, USA
| | - Yan Huang
- Discovery Therapeutics, Shire Pharmaceuticals, Lexington, MA, USA.,Drug Discovery, Shire, Cambridge, MA, USA
| | - Chuan Shen
- Discovery Therapeutics, Shire Pharmaceuticals, Lexington, MA, USA.,Drug Discovery, Shire, Cambridge, MA, USA
| | - Kathleen Palmieri
- Research, Shire Pharmaceuticals, Lexington, MA, 02421, USA.,Drug Discovery, Shire, Cambridge, MA, USA
| | - Robert Crooker
- Research, Shire Pharmaceuticals, Lexington, MA, 02421, USA.,Drug Discovery, Shire, Cambridge, MA, USA
| | - Dianna Lundberg
- Discovery Therapeutics, Shire Pharmaceuticals, Lexington, MA, USA.,Drug Discovery, Shire, Cambridge, MA, USA
| | - Niksa Kastrapeli
- Discovery Therapeutics, Shire Pharmaceuticals, Lexington, MA, USA.,Drug Discovery, Shire, Cambridge, MA, USA
| | - Brian Pescatore
- Discovery Therapeutics, Shire Pharmaceuticals, Lexington, MA, USA.,Drug Discovery, Shire, Cambridge, MA, USA
| | - Alla Romashko
- Discovery Therapeutics, Shire Pharmaceuticals, Lexington, MA, USA.,Drug Discovery, Shire, Cambridge, MA, USA
| | - John Dumas
- Discovery Therapeutics, Shire Pharmaceuticals, Lexington, MA, USA.,Drug Discovery, Shire, Cambridge, MA, USA
| | - Robert Comeau
- Discovery Therapeutics, Shire Pharmaceuticals, Lexington, MA, USA.,Drug Discovery, Shire, Cambridge, MA, USA
| | - Angela Norton
- Discovery Therapeutics, Shire Pharmaceuticals, Lexington, MA, USA.,Drug Discovery, Shire, Cambridge, MA, USA
| | - Jing Pan
- Discovery Therapeutics, Shire Pharmaceuticals, Lexington, MA, USA.,Drug Discovery, Shire, Cambridge, MA, USA
| | - Haojing Rong
- Nonclinical Development, Shire Pharmaceuticals, Lexington, MA, USA.,Drug Discovery, Shire, Cambridge, MA, USA
| | - Katayoun Derakhchan
- Nonclinical Development, Shire Pharmaceuticals, Lexington, MA, USA.,Drug Discovery, Shire, Cambridge, MA, USA
| | - David E Ehmann
- Research, Shire Pharmaceuticals, Lexington, MA, 02421, USA. .,Drug Discovery, Shire, Cambridge, MA, USA.
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70
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Bak DH, Choi MJ, Lee E, Kwon TR, Kim JH, Nam SH, Kim KY, Ahn SW, Mun SK, Na J, Kim BJ. A comparison study of prabotulinumtoxinA vs onabotulinumtoxinA in myostatin-deficient mice with muscle hypertrophy. Basic Clin Pharmacol Toxicol 2018; 124:491-499. [PMID: 30326173 DOI: 10.1111/bcpt.13151] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Accepted: 10/10/2018] [Indexed: 12/21/2022]
Abstract
Botulinum toxin A (BoNT-A) is used clinically for various muscle disorders and acts by preventing the release of the neurotransmitter acetylcholine into the synapse space. Here, we compared the efficacy of prabotulinumtoxinA (PRA) and onabotulinumtoxinA (ONA) for the reduction in hypertrophy in myostatin-deficient (Mstn-/- ) mice. Two different BoNT-A products (2.5, 10 and 25 U/kg) were injected to paralyse the hindlimb for 2 months, after which sciatic nerve conduction study, 3D micro-CT, haematoxylin and eosin (H&E) and dystrophin staining were conducted. Administration of BoNT-A products induced denervation-mediated atrophy and alleviated muscle hypertrophy generated in Mstn-/- mice. The present study revealed that each BoNT-A regulates skeletal muscle size, myofibre number and myofibre diameter in Mstn-/- mice. The potential applicability of BoNT-A for the treatment of rare muscle hypertrophic diseases was demonstrated. Compared with ONA, PRA had a comparable ability to act in the local area.
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Affiliation(s)
- Dong-Ho Bak
- Department of Dermatology, College of Medicine, Chung-Ang University, Seoul, Korea.,Department of Medicine, Graduate School, Chung-Ang University, Seoul, Korea
| | - Mi Ji Choi
- Department of Dermatology, College of Medicine, Chung-Ang University, Seoul, Korea.,Department of Medicine, Graduate School, Chung-Ang University, Seoul, Korea
| | - Esther Lee
- Department of Dermatology, College of Medicine, Chung-Ang University, Seoul, Korea.,Department of Medicine, Graduate School, Chung-Ang University, Seoul, Korea
| | - Tae-Rin Kwon
- Department of Dermatology, College of Medicine, Chung-Ang University, Seoul, Korea
| | - Jong Hwan Kim
- Department of Dermatology, College of Medicine, Chung-Ang University, Seoul, Korea.,Department of Medicine, Graduate School, Chung-Ang University, Seoul, Korea
| | | | | | | | - Seog-Kyun Mun
- Department of Otorhinolaryngology-Head and Neck Surgery, College of Medicine, Chung-Ang University, Seoul, Korea
| | - Jungtae Na
- Department of Dermatology, College of Medicine, Chung-Ang University, Seoul, Korea
| | - Beom Joon Kim
- Department of Dermatology, College of Medicine, Chung-Ang University, Seoul, Korea.,Department of Medicine, Graduate School, Chung-Ang University, Seoul, Korea
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71
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Lessard SJ, MacDonald TL, Pathak P, Han MS, Coffey VG, Edge J, Rivas DA, Hirshman MF, Davis RJ, Goodyear LJ. JNK regulates muscle remodeling via myostatin/SMAD inhibition. Nat Commun 2018; 9:3030. [PMID: 30072727 PMCID: PMC6072737 DOI: 10.1038/s41467-018-05439-3] [Citation(s) in RCA: 64] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2018] [Accepted: 07/06/2018] [Indexed: 01/30/2023] Open
Abstract
Skeletal muscle has a remarkable plasticity to adapt and remodel in response to environmental cues, such as physical exercise. Endurance exercise stimulates improvements in muscle oxidative capacity, while resistance exercise induces muscle growth. Here we show that the c-Jun N-terminal kinase (JNK) is a molecular switch that when active, stimulates muscle fibers to grow, resulting in increased muscle mass. Conversely, when muscle JNK activation is suppressed, an alternative remodeling program is initiated, resulting in smaller, more oxidative muscle fibers, and enhanced aerobic fitness. When muscle is exposed to mechanical stress, JNK initiates muscle growth via phosphorylation of the transcription factor, SMAD2, at specific linker region residues leading to inhibition of the growth suppressor, myostatin. In human skeletal muscle, this JNK/SMAD signaling axis is activated by resistance exercise, but not endurance exercise. We conclude that JNK acts as a key mediator of muscle remodeling during exercise via regulation of myostatin/SMAD signaling.
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Affiliation(s)
- Sarah J Lessard
- Research Division, Joslin Diabetes Center, Boston, 02215, MA, USA.
- Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, 02215, MA, USA.
| | - Tara L MacDonald
- Research Division, Joslin Diabetes Center, Boston, 02215, MA, USA
- Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, 02215, MA, USA
| | - Prerana Pathak
- Research Division, Joslin Diabetes Center, Boston, 02215, MA, USA
| | - Myoung Sook Han
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, 01605, MA, USA
| | - Vernon G Coffey
- Faculty of Health Sciences and Medicine, Bond University, Gold Coast, 4226, QLD, Australia
- School of Medical Science, RMIT University, Melbourne, 3000, Australia
| | - Johann Edge
- Massey University, Palmerston North, 4442, New Zealand
| | - Donato A Rivas
- Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University, Boston, 02111, MA, USA
| | | | - Roger J Davis
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, 01605, MA, USA
- Howard Hughes Medical Institute, University of Massachusetts Medical School, Worcester, 01605, MA, USA
| | - Laurie J Goodyear
- Research Division, Joslin Diabetes Center, Boston, 02215, MA, USA
- Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, 02215, MA, USA
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72
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Mah JK, Chen YW. A Pediatric Review of Facioscapulohumeral Muscular Dystrophy. JOURNAL OF PEDIATRIC NEUROLOGY 2018; 16:222-231. [PMID: 30923442 PMCID: PMC6435288 DOI: 10.1055/s-0037-1604197] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Facioscapulohumeral dystrophy is one of the most common forms of muscular dystrophies worldwide. It is a complex and heterogeneous disease secondary to insufficient epigenetic repression of D4Z4 repeats and aberrant expression of DUX4 in skeletal muscles. Type 1 facioscapulohumeral muscular dystrophy (FSHD) is caused by contraction of D4Z4 repeats on 4q35, whereas type 2 FSHD is associated with mutations of the SMCHD1 or DNMT3B gene in the presence of a disease-permissive 4qA haplotype. Classical FSHD is a slowly progressive disorder with gradual-onset of muscle atrophy and a descending pattern of muscle weakness. In contrast, early-onset FSHD is associated with a large deletion of D4Z4 repeats and a more severe disease phenotype, including early loss of independent ambulation as well as extramuscular manifestations, such as retinal vasculopathy, hearing loss, and central nervous system (CNS) involvement. However, the correlation between D4Z4 repeats and disease severity remains imprecise. The current standard of care guidelines offers comprehensive assessment and symptomatic management of secondary complications. Several clinical trials are currently underway for FSHD. New and emerging treatments focus on correcting the transcriptional misregulation of D4Z4 and reversing the cytotoxic effects of DUX4. Other potential therapeutic targets include reduction of inflammation, improving muscle mass, and activating compensatory molecular pathways. The utility of disease-modifying treatments will depend on selection of sensitive clinical endpoints as well as validation of muscle magnetic resonance imaging (MRI) and other biomarkers to detect meaningful changes in disease progression. Correction of the epigenetic defects using new gene editing as well as other DUX4 silencing technologies offers potential treatment options for many individuals with FSHD.
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Affiliation(s)
- Jean K. Mah
- Department of Pediatrics and Clinical Neurosciences, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Yi-Wen Chen
- Center for Genetic Medicine Research, Children’s National Health System, Washington, District of Columbia, United States
- Department of Integrative Systems Biology, George Washington University, Washington, District of Columbia, United States
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73
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Butcher JT, Ali MI, Ma MW, McCarthy CG, Islam BN, Fox LG, Mintz JD, Larion S, Fulton DJ, Stepp DW. Effect of myostatin deletion on cardiac and microvascular function. Physiol Rep 2018; 5. [PMID: 29192067 PMCID: PMC5727279 DOI: 10.14814/phy2.13525] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2017] [Revised: 10/13/2017] [Accepted: 10/20/2017] [Indexed: 12/20/2022] Open
Abstract
The objective of this study is to test the hypothesis that increased muscle mass has positive effects on cardiovascular function. Specifically, we tested the hypothesis that increases in lean body mass caused by deletion of myostatin improves cardiac performance and vascular function. Echocardiography was used to quantify left ventricular function at baseline and after acute administration of propranolol and isoproterenol to assess β‐adrenergic reactivity. Additionally, resistance vessels in several beds were removed, cannulated, pressurized to 60 mmHg and reactivity to vasoactive stimuli was assessed. Hemodynamics were measured using in vivo radiotelemetry. Myostatin deletion results in increased fractional shortening at baseline. Additionally, arterioles in the coronary and muscular microcirculations are more sensitive to endothelial‐dependent dilation while nonmuscular beds or the aorta were unaffected. β‐adrenergic dilation was increased in both coronary and conduit arteries, suggesting a systemic effect of increased muscle mass on vascular function. Overall hemodynamics and physical characteristics (heart weight and size) remained unchanged. Myostatin deletion mimics in part the effects of exercise on cardiovascular function. It significantly increases lean muscle mass and results in muscle‐specific increases in endothelium‐dependent vasodilation. This suggests that increases in muscle mass may serve as a buffer against pathological states that specifically target cardiac function (heart failure), the β‐adrenergic system (age), and nitric oxide bio‐availability (atherosclerosis). Taken together, pharmacological inhibition of the myostatin pathway could prove an excellent mechanism by which the benefits of exercise can be conferred in patients that are unable to exercise.
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Affiliation(s)
- Joshua T Butcher
- Department of Pharmacology, Department of Physiology, Vascular Biology Center, Augusta University, Augusta, Georgia
| | - M Irfan Ali
- Department of Pharmacology, Department of Physiology, Vascular Biology Center, Augusta University, Augusta, Georgia
| | - Merry W Ma
- Department of Pharmacology, Department of Physiology, Vascular Biology Center, Augusta University, Augusta, Georgia
| | - Cameron G McCarthy
- Department of Pharmacology, Department of Physiology, Vascular Biology Center, Augusta University, Augusta, Georgia
| | - Bianca N Islam
- Department of Pharmacology, Department of Physiology, Vascular Biology Center, Augusta University, Augusta, Georgia
| | - Lauren G Fox
- Department of Pharmacology, Department of Physiology, Vascular Biology Center, Augusta University, Augusta, Georgia
| | - James D Mintz
- Department of Pharmacology, Department of Physiology, Vascular Biology Center, Augusta University, Augusta, Georgia
| | - Sebastian Larion
- Department of Pharmacology, Department of Physiology, Vascular Biology Center, Augusta University, Augusta, Georgia
| | - David J Fulton
- Department of Pharmacology, Department of Physiology, Vascular Biology Center, Augusta University, Augusta, Georgia
| | - David W Stepp
- Department of Pharmacology, Department of Physiology, Vascular Biology Center, Augusta University, Augusta, Georgia
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74
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March JT, Golshirazi G, Cernisova V, Carr H, Leong Y, Lu-Nguyen N, Popplewell LJ. Targeting TGFβ Signaling to Address Fibrosis Using Antisense Oligonucleotides. Biomedicines 2018; 6:biomedicines6030074. [PMID: 29941814 PMCID: PMC6164894 DOI: 10.3390/biomedicines6030074] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Revised: 06/13/2018] [Accepted: 06/14/2018] [Indexed: 12/29/2022] Open
Abstract
Fibrosis results from the excessive accumulation of extracellular matrix in chronically injured tissue. The fibrotic process is governed by crosstalk between many signaling pathways. The search for an effective treatment is further complicated by the fact that there is a degree of tissue-specificity in the pathways involved, although the process is not completely understood for all tissues. A plethora of drugs have shown promise in pre-clinical models, which is not always borne out translationally in clinical trial. With the recent approvals of two antisense oligonucleotides for the treatment of the genetic diseases Duchenne muscular dystrophy and spinal muscular atrophy, we explore here the potential of antisense oligonucleotides to knockdown the expression of pro-fibrotic proteins. We give an overview of the generalized fibrotic process, concentrating on key players and highlight where antisense oligonucleotides have been used effectively in cellular and animal models of different fibrotic conditions. Consideration is given to the advantages antisense oligonucleotides would have as an anti-fibrotic therapy alongside factors that would need to be addressed to improve efficacy. A prospective outlook for the development of antisense oligonucleotides to target fibrosis is outlined.
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Affiliation(s)
- James T March
- Centre for Gene and Cell Therapy, School of Biological Sciences, Royal Holloway-University of London, Egham, Surrey TW20 0EX, UK.
| | - Golnoush Golshirazi
- Centre for Gene and Cell Therapy, School of Biological Sciences, Royal Holloway-University of London, Egham, Surrey TW20 0EX, UK.
| | - Viktorija Cernisova
- Centre for Gene and Cell Therapy, School of Biological Sciences, Royal Holloway-University of London, Egham, Surrey TW20 0EX, UK.
| | - Heidi Carr
- Centre for Gene and Cell Therapy, School of Biological Sciences, Royal Holloway-University of London, Egham, Surrey TW20 0EX, UK.
| | - Yee Leong
- Centre for Gene and Cell Therapy, School of Biological Sciences, Royal Holloway-University of London, Egham, Surrey TW20 0EX, UK.
| | - Ngoc Lu-Nguyen
- Centre for Gene and Cell Therapy, School of Biological Sciences, Royal Holloway-University of London, Egham, Surrey TW20 0EX, UK.
| | - Linda J Popplewell
- Centre for Gene and Cell Therapy, School of Biological Sciences, Royal Holloway-University of London, Egham, Surrey TW20 0EX, UK.
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75
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Shen C, Iskenderian A, Lundberg D, He T, Palmieri K, Crooker R, Deng Q, Traylor M, Gu S, Rong H, Ehmann D, Pescatore B, Strack-Logue B, Romashko A, Baviello G, Gill J, Zhang B, Meiyappan M, Pan C, Norton AW. Protein Engineering on Human Recombinant Follistatin: Enhancing Pharmacokinetic Characteristics for Therapeutic Application. J Pharmacol Exp Ther 2018; 366:291-302. [DOI: 10.1124/jpet.118.248195] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Accepted: 05/07/2018] [Indexed: 01/10/2023] Open
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76
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Muscle wasting in osteoarthritis model induced by anterior cruciate ligament transection. PLoS One 2018; 13:e0196682. [PMID: 29709011 PMCID: PMC5927423 DOI: 10.1371/journal.pone.0196682] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2017] [Accepted: 04/17/2018] [Indexed: 12/02/2022] Open
Abstract
This study aimed to investigate the molecular pathways involved in muscle wasting in an animal model of osteoarthritis (OA) induced by anterior cruciate ligament transection (ACLT) in rats. Reduction of protein syntheses, increased proteolysis and impaired muscle regeneration are important pathways related to muscle wasting, and myogenin, MyoD, myostatin and MuRF-1 are some of their markers. Female Wistar rats were allocated into two groups: OA (submitted to the ACLT) and SHAM (submitted to surgery without ACLT). Nociception, spontaneous exploratory locomotion and body weight of animals were evaluated weekly. Twelve weeks after the disease induction, animals were euthanized, and the right knee joints were collected. Gastrocnemius muscle of the right hind paw were dissected and weighed. Gastrocnemius was used for evaluation of muscle atrophy and expression of IL-1β, TNF-α, Pax7, myogenin, MyoD, myostatin and MuRF-1. Histopathology of the knee confirmed the development of the disease in animals of OA group. Gastrocnemius of OA animals showed a reduction of about 10% in area and an increased IL-1β expression compared to animals of SHAM group. Expression of myostatin was increased in OA group, while myogenin expression was decreased. TNF-α, Pax7, MuRF-1 and MyoD expression was similar in both OA and SHAM groups. Nociception was significantly elevated in OA animals in the last two weeks of experimental period. Spontaneous exploratory locomotion, body weight and weight of gastrocnemius showed no difference between OA and SHAM groups. Gastrocnemius atrophy in OA induced by ACLT involves elevated expression of IL-1β within the muscle, as well as increased expression of myostatin and decreased expression of myogenin. Therefore, muscle wasting may be linked to impaired muscle regeneration.
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77
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Blocking extracellular activation of myostatin as a strategy for treating muscle wasting. Sci Rep 2018; 8:2292. [PMID: 29396542 PMCID: PMC5797207 DOI: 10.1038/s41598-018-20524-9] [Citation(s) in RCA: 68] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2017] [Accepted: 01/18/2018] [Indexed: 12/22/2022] Open
Abstract
Many growth factors are intimately bound to the extracellular matrix, with regulated processing and release leading to cellular stimulation. Myostatin and GDF11 are closely related members of the TGFβ family whose activation requires two proteolytic cleavages to release the growth factor from the prodomain. Specific modulation of myostatin and GDF11 activity by targeting growth factor-receptor interactions has traditionally been challenging. Here we demonstrate that a novel strategy for blocking myostatin and GDF11, inhibition of growth factor release, specifically and potently inhibits signaling both in vitro and in vivo. We developed human monoclonal antibodies that selectively bind the myostatin and GDF11 precursor forms, including a subset that inhibit myostatin proteolytic activation and prevent muscle atrophy in vivo. The most potent myostatin activation-blocking antibodies promoted robust muscle growth and resulted in significant gains in muscle performance in healthy mice. Altogether, we show that blocking the extracellular activation of growth factors is a potent method for preventing signaling, serving as proof of concept for a novel therapeutic strategy that can be applied to other members of the TGFβ family of growth factors.
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78
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Paul R, Lee J, Donaldson AV, Connolly M, Sharif M, Natanek SA, Rosendahl U, Polkey MI, Griffiths M, Kemp PR. miR-422a suppresses SMAD4 protein expression and promotes resistance to muscle loss. J Cachexia Sarcopenia Muscle 2018; 9:119-128. [PMID: 28984049 PMCID: PMC5803610 DOI: 10.1002/jcsm.12236] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/07/2017] [Revised: 07/21/2017] [Accepted: 08/03/2017] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND Loss of muscle mass and strength are important sequelae of chronic disease, but the response of individuals is remarkably variable, suggesting important genetic and epigenetic modulators of muscle homeostasis. Such factors are likely to modify the activity of pathways that regulate wasting, but to date, few such factors have been identified. METHODS The effect of miR-422a on SMAD4 expression and transforming growth factor (TGF)-β signalling were determined by western blotting and luciferase assay. miRNA expression was determined by qPCR in plasma and muscle biopsy samples from a cross-sectional study of patients with chronic obstructive pulmonary disease (COPD) and a longitudinal study of patients undergoing aortic surgery, who were subsequently admitted to the intensive care unit (ICU). RESULTS miR-422a was identified, by a screen, as a microRNA that was present in the plasma of patients with COPD and negatively associated with muscle strength as well as being readily detectable in the muscle of patients. In vitro, miR-422a suppressed SMAD4 expression and inhibited TGF-beta and bone morphogenetic protein-dependent luciferase activity in muscle cells. In male patients with COPD and those undergoing aortic surgery and on the ICU, a model of ICU-associated muscle weakness, quadriceps expression of miR-422a was positively associated with muscle strength (maximal voluntary contraction r = 0.59, P < 0.001 and r = 0.51, P = 0.004, for COPD and aortic surgery, respectively). Furthermore, pre-surgery levels of miR-422a were inversely associated with the amount of muscle that would be lost in the first post-operative week (r = -0.57, P < 0.001). CONCLUSIONS These data suggest that differences in miR-422a expression contribute to the susceptibility to muscle wasting associated with chronic and acute disease and that at least part of this activity may be mediated by reduced TGF-beta signalling in skeletal muscle.
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Affiliation(s)
- Richard Paul
- Molecular Medicine Section, National Heart & Lung Institute, Imperial College London, South Kensington Campus, London, SW7 2AZ, UK.,National Institute for Health Research Respiratory Biomedical Research Unit at Royal Brompton and Harefield NHS Foundation Trust and Imperial College, London, SW3 6NP, UK
| | - Jen Lee
- Molecular Medicine Section, National Heart & Lung Institute, Imperial College London, South Kensington Campus, London, SW7 2AZ, UK
| | - Anna V Donaldson
- Molecular Medicine Section, National Heart & Lung Institute, Imperial College London, South Kensington Campus, London, SW7 2AZ, UK.,National Institute for Health Research Respiratory Biomedical Research Unit at Royal Brompton and Harefield NHS Foundation Trust and Imperial College, London, SW3 6NP, UK
| | - Martin Connolly
- Molecular Medicine Section, National Heart & Lung Institute, Imperial College London, South Kensington Campus, London, SW7 2AZ, UK
| | - Mohammad Sharif
- Molecular Medicine Section, National Heart & Lung Institute, Imperial College London, South Kensington Campus, London, SW7 2AZ, UK
| | - Samantha Amanda Natanek
- Molecular Medicine Section, National Heart & Lung Institute, Imperial College London, South Kensington Campus, London, SW7 2AZ, UK
| | - Ulrich Rosendahl
- Department of Cardiothoracic Surgery, Royal Brompton and Harefield NHS Foundation Trust, London, SW3 6NP, UK
| | - Michael I Polkey
- National Institute for Health Research Respiratory Biomedical Research Unit at Royal Brompton and Harefield NHS Foundation Trust and Imperial College, London, SW3 6NP, UK
| | - Mark Griffiths
- Inflammation, Regeneration and Development, National Heart and Lung Institute, Imperial College London, South Kensington Campus, London, SW7 2AZ, UK
| | - Paul R Kemp
- Molecular Medicine Section, National Heart & Lung Institute, Imperial College London, South Kensington Campus, London, SW7 2AZ, UK
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79
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Past, Present, and Future Perspective of Targeting Myostatin and Related Signaling Pathways to Counteract Muscle Atrophy. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2018; 1088:153-206. [DOI: 10.1007/978-981-13-1435-3_8] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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80
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Gosch M, Wicklein S. [Antibodies as treatment option in older adults]. Z Gerontol Geriatr 2017; 51:152-156. [PMID: 29264687 DOI: 10.1007/s00391-017-1352-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: 10/23/2017] [Revised: 10/30/2017] [Accepted: 11/17/2017] [Indexed: 10/18/2022]
Abstract
Monoclonal antibodies are already used for many different clinical indications. Besides oncology and rheumatology, denosumab is the only antibody that is currently prescribed in older adults with osteoporosis; however, apart from osteoporosis there might be more possible indications for the use of antibodies in chronic diseases and geriatric syndromes. Particularly, with respect to sarcopenia the transition to "doping for older adults" seems to be fluent. The present review provides an overview on the newest developments and prospective options.
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Affiliation(s)
- M Gosch
- Medizinische Klinik 2 - Schwerpunkt Geriatrie, Universitätsklinik für Geriatrie, Klinikum Nürnberg, Paracelsus Medizinische Privatuniversität, Campus Nürnberg, Prof.-Ernst-Nathan-Str. 1, 90419, Nürnberg, Deutschland.
| | - S Wicklein
- Medizinische Klinik 2 - Schwerpunkt Geriatrie, Universitätsklinik für Geriatrie, Klinikum Nürnberg, Paracelsus Medizinische Privatuniversität, Campus Nürnberg, Prof.-Ernst-Nathan-Str. 1, 90419, Nürnberg, Deutschland
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81
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Tang L, Li N, Jian W, Kang Y, Yin B, Sun S, Guo J, Sun L, Ta D. Low-intensity pulsed ultrasound prevents muscle atrophy induced by type 1 diabetes in rats. Skelet Muscle 2017; 7:29. [PMID: 29273088 PMCID: PMC5741922 DOI: 10.1186/s13395-017-0145-7] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2017] [Accepted: 11/29/2017] [Indexed: 01/08/2023] Open
Abstract
Background Type 1 diabetes mellitus (T1DM) induces serious skeletal muscle atrophy. Low-intensity pulsed ultrasound (LIPUS) is a common treatment for skeletal muscle injury and is effective in accelerating the rate of muscle growth. However, to the best of our knowledge, whether LIPUS can improve skeletal muscle atrophy in type 1 diabetic rats has not been investigated. Methods The rats were randomly divided into four groups: the normal control group (NC); the sham-treated diabetic control group (DC); the diabetic, insulin-treated group (DI) as a positive control; and the diabetic LIPUS therapy group (DL). The DL rats were treated with LIPUS (1 MHz, 30 mW/cm2) on the gastrocnemius for 20 min/day. Results After 6 weeks, the rats in the DC group showed severe muscle atrophy. However, LIPUS significantly improved type 1 diabetes-induced muscle atrophy, as evidenced by significantly enhanced muscle cross-sectional area, muscle mass, and strength. Moreover, compared with the DC group, LIPUS significantly activated Akt and upregulated the expression of mTOR, and LIPUS downregulated the expression of MSTN, its receptor ActRIIB, and FoxO1. Conclusions These results indicate that LIPUS improved muscle atrophy induced by type 1 diabetes, and the MSTN/Akt/mTOR&FoxO1 signaling pathway may play a role in this improvement.
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Affiliation(s)
- Liang Tang
- Institute of Sports Biology, Shaanxi Normal University, Xi'an, 710119, China
| | - Nan Li
- Institute of Sports Biology, Shaanxi Normal University, Xi'an, 710119, China.,Leisure Management College, Xi'an Eurasia University, Xi'an, China
| | - Wenqi Jian
- Institute of Sports Biology, Shaanxi Normal University, Xi'an, 710119, China
| | - Yiting Kang
- Institute of Sports Biology, Shaanxi Normal University, Xi'an, 710119, China
| | - Bo Yin
- Institute of Sports Biology, Shaanxi Normal University, Xi'an, 710119, China
| | - Shuxin Sun
- Department of Electronic Engineering, Fudan University, Shanghai, 200433, China
| | - Jianzhong Guo
- Shaanxi Key Laboratory of Ultrasonics, Shaanxi Normal University, Xi'an, China
| | - Lijun Sun
- Institute of Sports Biology, Shaanxi Normal University, Xi'an, 710119, China.
| | - Dean Ta
- Department of Electronic Engineering, Fudan University, Shanghai, 200433, China. .,Key Laboratory of Medical Imaging Computing and Computer Assisted Intervention (MICCAI) of Shanghai, Shanghai, China.
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82
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Deng Z, Luo P, Lai W, Song T, Peng J, Wei HK. Myostatin inhibits eEF2K-eEF2 by regulating AMPK to suppress protein synthesis. Biochem Biophys Res Commun 2017; 494:278-284. [DOI: 10.1016/j.bbrc.2017.10.040] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2017] [Accepted: 10/07/2017] [Indexed: 02/07/2023]
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83
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Dogra D, Ahuja S, Kim HT, Rasouli SJ, Stainier DYR, Reischauer S. Opposite effects of Activin type 2 receptor ligands on cardiomyocyte proliferation during development and repair. Nat Commun 2017; 8:1902. [PMID: 29196619 PMCID: PMC5711791 DOI: 10.1038/s41467-017-01950-1] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2017] [Accepted: 10/27/2017] [Indexed: 01/14/2023] Open
Abstract
Zebrafish regenerate damaged myocardial tissue very effectively. Hence, insights into the molecular networks underlying zebrafish heart regeneration might help develop alternative strategies to restore human cardiac performance. While TGF-β signaling has been implicated in zebrafish cardiac regeneration, the role of its individual ligands remains unclear. Here, we report the opposing expression response during zebrafish heart regeneration of two genes, mstnb and inhbaa, which encode TGF-β family ligands. Using gain-of-function (GOF) and loss-of-function (LOF) approaches, we show that these ligands mediate inverse effects on cardiac regeneration and specifically on cardiomyocyte (CM) proliferation. Notably, we find that Inhbaa functions as a CM mitogen and that its overexpression leads to accelerated cardiac recovery and scar clearance after injury. In contrast, mstnb GOF and inhbaa LOF both lead to unresolved scarring after cardiac injury. We further show that Mstnb and Inhbaa inversely control Smad2 and Smad3 transcription factor activities through alternate Activin type 2 receptors. Zebrafish can regenerate damaged myocardial tissue but it is unclear how this is regulated. Here, the authors show that two TGF-β family members, Mstnb and Inhbaa, have opposite effects in regeneration, with mstnb overexpression or inhbaa loss-of-function causing cardiac scarring after injury.
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Affiliation(s)
- Deepika Dogra
- Department of Developmental Genetics, Max Planck Institute for Heart and Lung Research, 61231, Bad Nauheim, Germany
| | - Suchit Ahuja
- Department of Developmental Genetics, Max Planck Institute for Heart and Lung Research, 61231, Bad Nauheim, Germany
| | - Hyun-Taek Kim
- Department of Developmental Genetics, Max Planck Institute for Heart and Lung Research, 61231, Bad Nauheim, Germany
| | - S Javad Rasouli
- Department of Developmental Genetics, Max Planck Institute for Heart and Lung Research, 61231, Bad Nauheim, Germany
| | - Didier Y R Stainier
- Department of Developmental Genetics, Max Planck Institute for Heart and Lung Research, 61231, Bad Nauheim, Germany.,Department of Biochemistry and Biophysics, University of California San Francisco, San Francisco, 94158, CA, USA
| | - Sven Reischauer
- Department of Developmental Genetics, Max Planck Institute for Heart and Lung Research, 61231, Bad Nauheim, Germany. .,Department of Biochemistry and Biophysics, University of California San Francisco, San Francisco, 94158, CA, USA.
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84
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Blockade of activin type II receptors with a dual anti-ActRIIA/IIB antibody is critical to promote maximal skeletal muscle hypertrophy. Proc Natl Acad Sci U S A 2017; 114:12448-12453. [PMID: 29109273 PMCID: PMC5703284 DOI: 10.1073/pnas.1707925114] [Citation(s) in RCA: 78] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
We recently reported that activin type II receptors (ActRIIs) blockade using bimagrumab could positively impact muscle wasting in mice and humans. However, the specific role of each individual ActRII at regulating adult muscle mass had not been clarified. Here, we highlight the importance of concomitant neutralization of both ActRIIs in controlling muscle mass. Through comparison with single specificity antibodies, we uncover unique features related to bimagrumab and its neutralizing interactions with both ActRIIA and ActRIIB at the structural and cellular levels and in vivo in adult mice. The need for simultaneous engagement and neutralization of both ActRIIs to generate a strong skeletal muscle response confers unique therapeutic potential to bimagrumab, in the context of muscle wasting conditions. The TGF-β family ligands myostatin, GDF11, and activins are negative regulators of skeletal muscle mass, which have been reported to primarily signal via the ActRIIB receptor on skeletal muscle and thereby induce muscle wasting described as cachexia. Use of a soluble ActRIIB-Fc “trap,” to block myostatin pathway signaling in normal or cachectic mice leads to hypertrophy or prevention of muscle loss, perhaps suggesting that the ActRIIB receptor is primarily responsible for muscle growth regulation. Genetic evidence demonstrates however that both ActRIIB- and ActRIIA-deficient mice display a hypertrophic phenotype. Here, we describe the mode of action of bimagrumab (BYM338), as a human dual-specific anti-ActRIIA/ActRIIB antibody, at the molecular and cellular levels. As shown by X-ray analysis, bimagrumab binds to both ActRIIA and ActRIIB ligand binding domains in a competitive manner at the critical myostatin/activin binding site, hence preventing signal transduction through either ActRII. Myostatin and the activins are capable of binding to both ActRIIA and ActRIIB, with different affinities. However, blockade of either single receptor through the use of specific anti-ActRIIA or anti-ActRIIB antibodies achieves only a partial signaling blockade upon myostatin or activin A stimulation, and this leads to only a small increase in muscle mass. Complete neutralization and maximal anabolic response are achieved only by simultaneous blockade of both receptors. These findings demonstrate the importance of ActRIIA in addition to ActRIIB in mediating myostatin and activin signaling and highlight the need for blocking both receptors to achieve a strong functional benefit.
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85
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Tarum J, Folkesson M, Atherton PJ, Kadi F. Electrical pulse stimulation: an in vitro exercise model for the induction of human skeletal muscle cell hypertrophy. A proof-of-concept study. Exp Physiol 2017; 102:1405-1413. [PMID: 28861930 DOI: 10.1113/ep086581] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Accepted: 08/30/2017] [Indexed: 12/23/2022]
Abstract
NEW FINDINGS What is the central question of this study? Is electrical pulse stimulation (EPS) an in vitro exercise model able to elicit the hypertrophy of human muscle cells? What is the main finding and its importance? The addition of a restitution period of 8 h after EPS induces the enlargement of human muscle cells, a major physiological end-point to resistance exercise. This is supported by downregulation of myostatin, a negative regulator of muscle mass, and increased phosphorylated mTOR and 4E-BP1, key factors in the growth cascade. This proof-of-concept study provides a model of physiologically mediated muscle growth, which will be the basis for future studies aiming to depict molecular events governing the hypertrophy of human muscle cells. Electrical pulse stimulation (EPS) of muscle cells has previously been used as an in vitro exercise model. The present study aimed to establish an EPS protocol promoting the hypertrophy of human muscle cells, which represents a major physiological end-point to resistance exercise in humans. We hypothesized that adding a resting period after EPS would be crucial for the occurrence of the morphological change. Myoblasts obtained from human muscle biopsies (n = 5) were differentiated into multinucleated myotubes and exposed to 8 h of EPS consisting of 2 ms pulses at 12 V, with a frequency of 1 Hz. Myotube size was assessed using immunohistochemistry immediately, 4 and 8 h after completed EPS. Gene expression and phosphorylation status of selected markers of hypertrophy were assessed using RT-PCR and Western blotting, respectively. Release of the myokine interleukin-6 in culture medium was measured using enzyme-linked immunosorbent assay. We demonstrated a significant increase (31 ± 14%; P = 0.03) in the size of myotubes when EPS was followed by an 8 h resting period, but not immediately or 4 h after completion of EPS. The response was supported by downregulation (P = 0.04) of the gene expression of myostatin, a negative regulator of muscle mass, and an increase in phosphorylated mTOR (P = 0.03) and 4E-BP1 (P = 0.01), which are important factors in the cellular growth signalling cascade. The present work demonstrates that EPS is an in vitro exercise model promoting the hypertrophy of human muscle cells, recapitulating a major physiological end-point to resistance exercise in human skeletal muscle.
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Affiliation(s)
- Janelle Tarum
- School of Health Sciences, Örebro University, 70182, Örebro, Sweden
| | | | - Philip J Atherton
- School of Medicine, Royal Derby Hospital, University of Nottingham, Derby, UK
| | - Fawzi Kadi
- School of Health Sciences, Örebro University, 70182, Örebro, Sweden
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86
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The histone deacetylase SIRT6 blocks myostatin expression and development of muscle atrophy. Sci Rep 2017; 7:11877. [PMID: 28928419 PMCID: PMC5605688 DOI: 10.1038/s41598-017-10838-5] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2017] [Accepted: 08/15/2017] [Indexed: 12/27/2022] Open
Abstract
Muscle wasting, also known as cachexia, is associated with many chronic diseases, which worsens prognosis of primary illness leading to enhanced mortality. Molecular basis of this metabolic syndrome is not yet completely understood. SIRT6 is a chromatin-bound member of the sirtuin family, implicated in regulating many cellular processes, ranging from metabolism, DNA repair to aging. SIRT6 knockout (SIRT6-KO) mice display loss of muscle, fat and bone density, typical characteristics of cachexia. Here we report that SIRT6 depletion in cardiac as well as skeletal muscle cells promotes myostatin (Mstn) expression. We also observed upregulation of other factors implicated in muscle atrophy, such as angiotensin-II, activin and Acvr2b, in SIRT6 depleted cells. SIRT6-KO mice showed degenerated skeletal muscle phenotype with significant fibrosis, an effect consistent with increased levels of Mstn. Additionally, we observed that in an in vivo model of cancer cachexia, Mstn expression coupled with downregulation of SIRT6. Furthermore, SIRT6 overexpression downregulated the cytokine (TNFα-IFNγ)-induced Mstn expression in C2C12 cells, and promoted myogenesis. From the ChIP assay, we found that SIRT6 controls Mstn expression by attenuating NF-κB binding to the Mstn promoter. Together, these data suggest a novel role for SIRT6 in maintaining muscle mass by controlling expression of atrophic factors like Mstn and activin.
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87
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Salzler RR, Shah D, Doré A, Bauerlein R, Miloscio L, Latres E, Papadopoulos NJ, Olson WC, MacDonald D, Duan X. Myostatin deficiency but not anti-myostatin blockade induces marked proteomic changes in mouse skeletal muscle. Proteomics 2017; 16:2019-27. [PMID: 27214824 DOI: 10.1002/pmic.201600006] [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: 01/08/2016] [Revised: 03/31/2016] [Accepted: 05/18/2016] [Indexed: 11/09/2022]
Abstract
Pharmacologic blockade of the myostatin (Mstn)/activin receptor pathway is being pursued as a potential therapy for several muscle wasting disorders. The functional benefits of blocking this pathway are under investigation, in particular given the findings that greater muscle hypertrophy results from Mstn deficiency arising from genetic ablation compared to post-developmental Mstn blockade. Using high-resolution MS coupled with SILAC mouse technology, we quantitated the relative proteomic changes in gastrocnemius muscle from Mstn knockout (Mstn(-/-) ) and mice treated for 2-weeks with REGN1033, an anti-Mstn antibody. Relative to wild-type animals, Mstn(-/-) mice had a two-fold greater muscle mass and a >1.5-fold change in expression of 12.0% of 1137 quantified muscle proteins. In contrast, mice treated with REGN1033 had minimal changes in muscle proteome (0.7% of 1510 proteins >1.5-fold change, similar to biological difference 0.5% of 1310) even though the treatment induced significant 20% muscle mass increase. Functional annotation of the altered proteins in Mstn(-/-) mice corroborates the mutiple physiological changes including slow-to-fast fiber type switch. Thus, the proteome-wide protein expression differs between Mstn(-/-) mice and mice subjected to specific Mstn blockade post-developmentally, providing molecular-level insights to inform mechanistic hypotheses to explain the observed functional differences.
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Affiliation(s)
- Robert R Salzler
- Therapeutic Proteins, Regeneron Pharmaceuticals, Tarrytown, NY, USA
| | - Darshit Shah
- Therapeutic Proteins, Regeneron Pharmaceuticals, Tarrytown, NY, USA
| | - Anthony Doré
- Therapeutic Proteins, Regeneron Pharmaceuticals, Tarrytown, NY, USA
| | - Roy Bauerlein
- Therapeutic Proteins, Regeneron Pharmaceuticals, Tarrytown, NY, USA
| | - Lawrence Miloscio
- Muscle and Metabolism, Regeneron Pharmaceuticals, Tarrytown, NY, USA
| | - Esther Latres
- Muscle and Metabolism, Regeneron Pharmaceuticals, Tarrytown, NY, USA
| | | | - William C Olson
- Therapeutic Proteins, Regeneron Pharmaceuticals, Tarrytown, NY, USA
| | | | - Xunbao Duan
- Therapeutic Proteins, Regeneron Pharmaceuticals, Tarrytown, NY, USA
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88
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Hennebry A, Oldham J, Shavlakadze T, Grounds MD, Sheard P, Fiorotto ML, Falconer S, Smith HK, Berry C, Jeanplong F, Bracegirdle J, Matthews K, Nicholas G, Senna-Salerno M, Watson T, McMahon CD. IGF1 stimulates greater muscle hypertrophy in the absence of myostatin in male mice. J Endocrinol 2017; 234:187-200. [PMID: 28533420 DOI: 10.1530/joe-17-0032] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/23/2017] [Accepted: 05/22/2017] [Indexed: 01/02/2023]
Abstract
Insulin-like growth factors (IGFs) and myostatin have opposing roles in regulating the growth and size of skeletal muscle, with IGF1 stimulating, and myostatin inhibiting, growth. However, it remains unclear whether these proteins have mutually dependent, or independent, roles. To clarify this issue, we crossed myostatin null (Mstn-/-) mice with mice overexpressing Igf1 in skeletal muscle (Igf1+) to generate six genotypes of male mice; wild type (Mstn+/+ ), Mstn+/-, Mstn-/-, Mstn+/+:Igf1+, Mstn+/-:Igf1+ and Mstn-/-:Igf1+ Overexpression of Igf1 increased the mass of mixed fibre type muscles (e.g. Quadriceps femoris) by 19% over Mstn+/+ , 33% over Mstn+/- and 49% over Mstn-/- (P < 0.001). By contrast, the mass of the gonadal fat pad was correspondingly reduced with the removal of Mstn and addition of Igf1 Myostatin regulated the number, while IGF1 regulated the size of myofibres, and the deletion of Mstn and Igf1+ independently increased the proportion of fast type IIB myosin heavy chain isoforms in T. anterior (up to 10% each, P < 0.001). The abundance of AKT and rpS6 was increased in muscles of Mstn-/-mice, while phosphorylation of AKTS473 was increased in Igf1+mice (Mstn+/+:Igf1+, Mstn+/-:Igf1+ and Mstn-/-:Igf1+). Our results demonstrate that a greater than additive effect is observed on the growth of skeletal muscle and in the reduction of body fat when myostatin is absent and IGF1 is in excess. Finally, we show that myostatin and IGF1 regulate skeletal muscle size, myofibre type and gonadal fat through distinct mechanisms that involve increasing the total abundance and phosphorylation status of AKT and rpS6.
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Affiliation(s)
| | | | - Tea Shavlakadze
- School of AnatomyPhysiology & Human Biology, The University of Western Australia, Crawley, Western Australia, Australia
| | - Miranda D Grounds
- School of AnatomyPhysiology & Human Biology, The University of Western Australia, Crawley, Western Australia, Australia
| | - Philip Sheard
- Department of PhysiologyUniversity of Otago, Dunedin, New Zealand
| | - Marta L Fiorotto
- USDA/ARS Children's Nutrition Research CenterBaylor College of Medicine, Houston, Texas, USA
| | | | - Heather K Smith
- Department of Exercise SciencesUniversity of Auckland, Auckland, New Zealand
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89
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Latres E, Mastaitis J, Fury W, Miloscio L, Trejos J, Pangilinan J, Okamoto H, Cavino K, Na E, Papatheodorou A, Willer T, Bai Y, Hae Kim J, Rafique A, Jaspers S, Stitt T, Murphy AJ, Yancopoulos GD, Gromada J. Activin A more prominently regulates muscle mass in primates than does GDF8. Nat Commun 2017; 8:15153. [PMID: 28452368 PMCID: PMC5414365 DOI: 10.1038/ncomms15153] [Citation(s) in RCA: 113] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2016] [Accepted: 03/06/2017] [Indexed: 12/19/2022] Open
Abstract
Growth and differentiation factor 8 (GDF8) is a TGF-β superfamily member, and negative regulator of skeletal muscle mass. GDF8 inhibition results in prominent muscle growth in mice, but less impressive hypertrophy in primates, including man. Broad TGF-β inhibition suggests another family member negatively regulates muscle mass, and its blockade enhances muscle growth seen with GDF8-specific inhibition. Here we show that activin A is the long-sought second negative muscle regulator. Activin A specific inhibition, on top of GDF8 inhibition, leads to pronounced muscle hypertrophy and force production in mice and monkeys. Inhibition of these two ligands mimics the hypertrophy seen with broad TGF-β blockers, while avoiding the adverse effects due to inhibition of multiple family members. Altogether, we identify activin A as a second negative regulator of muscle mass, and suggest that inhibition of both ligands provides a preferred therapeutic approach, which maximizes the benefit:risk ratio for muscle diseases in man. Inhibition of GDF8 increases muscle mass in mice, but is less effective in monkeys and humans. Here the authors show that activin A also inhibits muscle hypertrophy and that concomitant inhibition of activin A and GDF8 synergistically increases muscle mass in mice and non-human primates.
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Affiliation(s)
- Esther Latres
- Regeneron Pharmaceuticals, Inc., 777 Old Saw Mill River Road, Tarrytown, New York 10591, USA
| | - Jason Mastaitis
- Regeneron Pharmaceuticals, Inc., 777 Old Saw Mill River Road, Tarrytown, New York 10591, USA
| | - Wen Fury
- Regeneron Pharmaceuticals, Inc., 777 Old Saw Mill River Road, Tarrytown, New York 10591, USA
| | - Lawrence Miloscio
- Regeneron Pharmaceuticals, Inc., 777 Old Saw Mill River Road, Tarrytown, New York 10591, USA
| | - Jesus Trejos
- Regeneron Pharmaceuticals, Inc., 777 Old Saw Mill River Road, Tarrytown, New York 10591, USA
| | - Jeffrey Pangilinan
- Regeneron Pharmaceuticals, Inc., 777 Old Saw Mill River Road, Tarrytown, New York 10591, USA
| | - Haruka Okamoto
- Regeneron Pharmaceuticals, Inc., 777 Old Saw Mill River Road, Tarrytown, New York 10591, USA
| | - Katie Cavino
- Regeneron Pharmaceuticals, Inc., 777 Old Saw Mill River Road, Tarrytown, New York 10591, USA
| | - Erqian Na
- Regeneron Pharmaceuticals, Inc., 777 Old Saw Mill River Road, Tarrytown, New York 10591, USA
| | - Angelos Papatheodorou
- Regeneron Pharmaceuticals, Inc., 777 Old Saw Mill River Road, Tarrytown, New York 10591, USA
| | - Tobias Willer
- Regeneron Pharmaceuticals, Inc., 777 Old Saw Mill River Road, Tarrytown, New York 10591, USA
| | - Yu Bai
- Regeneron Pharmaceuticals, Inc., 777 Old Saw Mill River Road, Tarrytown, New York 10591, USA
| | - Jee Hae Kim
- Regeneron Pharmaceuticals, Inc., 777 Old Saw Mill River Road, Tarrytown, New York 10591, USA
| | - Ashique Rafique
- Regeneron Pharmaceuticals, Inc., 777 Old Saw Mill River Road, Tarrytown, New York 10591, USA
| | - Stephen Jaspers
- Regeneron Pharmaceuticals, Inc., 777 Old Saw Mill River Road, Tarrytown, New York 10591, USA
| | - Trevor Stitt
- Regeneron Pharmaceuticals, Inc., 777 Old Saw Mill River Road, Tarrytown, New York 10591, USA
| | - Andrew J Murphy
- Regeneron Pharmaceuticals, Inc., 777 Old Saw Mill River Road, Tarrytown, New York 10591, USA
| | - George D Yancopoulos
- Regeneron Pharmaceuticals, Inc., 777 Old Saw Mill River Road, Tarrytown, New York 10591, USA
| | - Jesper Gromada
- Regeneron Pharmaceuticals, Inc., 777 Old Saw Mill River Road, Tarrytown, New York 10591, USA
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90
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Chen PR, Lee K. INVITED REVIEW: Inhibitors of myostatin as methods of enhancing muscle growth and development. J Anim Sci 2017; 94:3125-3134. [PMID: 27695802 DOI: 10.2527/jas.2016-0532] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/07/2022] Open
Abstract
With the increasing demand for affordable, high-quality meat, livestock and poultry producers must continually find ways to maximize muscle growth in their animals without compromising palatability of the meat products. Muscle mass relies on myoblast proliferation during prenatal or prehatch stages and fiber hypertrophy through protein synthesis and nuclei donation by satellite cells after birth or hatch. Therefore, understanding the cellular and molecular mechanisms of myogenesis and muscle development is of great interest. Myostatin is a well-known negative regulator of muscle growth and development that inhibits proliferation and differentiation in myogenic cells as well as protein synthesis in existing muscle fibers. In this review, various inhibitors of myostatin activity or signaling are examined that may be used in animal agriculture for enhancing muscle growth. Myostatin inhibitors are relevant as potential therapies for muscle-wasting diseases and muscle weakness in humans and animals. Currently, there are no commercial myostatin inhibitors for agriculture or biomedical purposes because the safest and most effective option has yet to be identified. Further investigation of myostatin inhibitors and administration strategies may revolutionize animal production and the medical field.
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91
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Lu-Nguyen N, Malerba A, Popplewell L, Schnell F, Hanson G, Dickson G. Systemic Antisense Therapeutics for Dystrophin and Myostatin Exon Splice Modulation Improve Muscle Pathology of Adult mdx Mice. MOLECULAR THERAPY. NUCLEIC ACIDS 2016; 6:15-28. [PMID: 28325281 PMCID: PMC5363451 DOI: 10.1016/j.omtn.2016.11.009] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Revised: 11/21/2016] [Accepted: 11/21/2016] [Indexed: 01/10/2023]
Abstract
Antisense-mediated exon skipping is a promising approach for the treatment of Duchenne muscular dystrophy (DMD), a rare life-threatening genetic disease due to dystrophin deficiency. Such an approach can restore the disrupted reading frame of dystrophin pre-mRNA, generating a truncated form of the protein. Alternatively, antisense therapy can be used to induce destructive exon skipping of myostatin pre-mRNA, knocking down myostatin expression to enhance muscle strength and reduce fibrosis. We have reported previously that intramuscular or intraperitoneal antisense administration inducing dual exon skipping of dystrophin and myostatin pre-mRNAs was beneficial in mdx mice, a mouse model of DMD, although therapeutic effects were muscle type restricted, possibly due to the delivery routes used. Here, following systemic intravascular antisense treatment, muscle strength and body activity of treated adult mdx mice increased to the levels of healthy controls. Importantly, hallmarks of muscular dystrophy were greatly improved in mice receiving the combined exon-skipping therapy, as compared to those receiving dystrophin antisense therapy alone. Our results support the translation of antisense therapy for dystrophin restoration and myostatin inhibition into the clinical setting for DMD.
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Affiliation(s)
- Ngoc Lu-Nguyen
- School of Biological Sciences, Royal Holloway-University of London, Egham, Surrey TW20 0EX, UK
| | - Alberto Malerba
- School of Biological Sciences, Royal Holloway-University of London, Egham, Surrey TW20 0EX, UK
| | - Linda Popplewell
- School of Biological Sciences, Royal Holloway-University of London, Egham, Surrey TW20 0EX, UK
| | - Fred Schnell
- Sarepta Therapeutics Inc., 215 First Street, Cambridge, MA 02142, USA
| | - Gunnar Hanson
- Sarepta Therapeutics Inc., 215 First Street, Cambridge, MA 02142, USA
| | - George Dickson
- School of Biological Sciences, Royal Holloway-University of London, Egham, Surrey TW20 0EX, UK.
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92
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Emerging therapies for the treatment of skeletal muscle wasting in chronic obstructive pulmonary disease. Pharmacol Ther 2016; 166:56-70. [DOI: 10.1016/j.pharmthera.2016.06.013] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/14/2016] [Indexed: 12/18/2022]
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93
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Matrix Metalloproteinase Responsive Delivery of Myostatin Inhibitors. Pharm Res 2016; 34:58-72. [DOI: 10.1007/s11095-016-2038-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2016] [Accepted: 09/06/2016] [Indexed: 12/21/2022]
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94
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Ost M, Coleman V, Kasch J, Klaus S. Regulation of myokine expression: Role of exercise and cellular stress. Free Radic Biol Med 2016; 98:78-89. [PMID: 26898145 DOI: 10.1016/j.freeradbiomed.2016.02.018] [Citation(s) in RCA: 85] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/30/2015] [Revised: 02/12/2016] [Accepted: 02/15/2016] [Indexed: 12/26/2022]
Abstract
Exercise training is well known to improve physical fitness and to combat chronic diseases and aging related disorders. Part of this is thought to be mediated by myokines, muscle derived secretory proteins (mainly cytokines) that elicit auto/paracrine but also endocrine effects on organs such as liver, adipose tissue, and bone. Today, several hundred potential myokines have been identified most of them not exclusive to muscle cells. Strenuous exercise is associated with increased production of free radicals and reactive oxidant species (ROS) as well as endoplasmic reticulum (ER)-stress which at an excessive level can lead to muscle damage and cell death. On the other hand, transient elevations in oxidative and ER-stress are thought to be necessary for adaptive improvements by regular exercise through a hormesis action termed mitohormesis since mitochondria are essential for the generation of energy and tightly connected to ER- and oxidative stress. Exercise induced myokines have been identified by various in vivo and in vitro approaches and accumulating evidence suggests that ROS and ER-stress linked pathways are involved in myokine induction. For example, interleukin (IL)-6, the prototypic exercise myokine is also induced by oxidative and ER-stress. Exercise induced expression of some myokines such as irisin and meteorin-like is linked to the transcription factor PGC-1α and apparently not related to ER-stress whereas typical ER-stress induced cytokines such as FGF-21 and GDF-15 are not exercise myokines under normal physiological conditions. Recent technological advances have led to the identification of numerous potential new myokines but for most of them regulation by oxidative and ER-stress still needs to be unraveled.
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Affiliation(s)
- Mario Ost
- Research Group Physiology of Energy Metabolism, German Institute of Human Nutrition in Potsdam Rehbrücke, Arthur-Scheunert-Allee 114-116, 14558 Nuthetal, Germany
| | - Verena Coleman
- Research Group Physiology of Energy Metabolism, German Institute of Human Nutrition in Potsdam Rehbrücke, Arthur-Scheunert-Allee 114-116, 14558 Nuthetal, Germany
| | - Juliane Kasch
- Research Group Physiology of Energy Metabolism, German Institute of Human Nutrition in Potsdam Rehbrücke, Arthur-Scheunert-Allee 114-116, 14558 Nuthetal, Germany
| | - Susanne Klaus
- Research Group Physiology of Energy Metabolism, German Institute of Human Nutrition in Potsdam Rehbrücke, Arthur-Scheunert-Allee 114-116, 14558 Nuthetal, Germany.
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95
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Zhou J, Liu B, Liang C, Li Y, Song YH. Cytokine Signaling in Skeletal Muscle Wasting. Trends Endocrinol Metab 2016; 27:335-347. [PMID: 27025788 DOI: 10.1016/j.tem.2016.03.002] [Citation(s) in RCA: 126] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/14/2016] [Revised: 03/04/2016] [Accepted: 03/04/2016] [Indexed: 02/07/2023]
Abstract
Skeletal muscle wasting occurs in a variety of diseases including diabetes, cancer, Crohn's disease, chronic obstructive pulmonary disease (COPD), disuse, and denervation. Tumor necrosis factor α (TNF-α) is involved in mediating the wasting effect. To date, a causal relationship between TNF-α signaling and muscle wasting has been established in animal models. However, results from clinical trials are conflicting. This is partly due to the fact that other factors such as TNF-like weak inducer of apoptosis (TWEAK) and interleukin 6 (IL-6) are also involved in skeletal muscle wasting. Because muscle wasting is often associated with physical inactivity and reduced food intake, therapeutic interventions will be most effective when multiple approaches are used in conjunction with nutritional support and exercise.
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Affiliation(s)
- Jin Zhou
- Department of General Surgery, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu, 215006, P.R. China
| | - Bin Liu
- Cardiovascular Disease Center, The First Hospital of Ji Lin University, Changchun, Jilin, 130021, P.R. China
| | - Chun Liang
- Department of Cardiology, ChangZheng Hospital, Second Military Medical University, Shanghai, 200003, P.R. China
| | - Yangxin Li
- Department of Cardiovascular Surgery and Institute of Cardiovascular Science, First Affiliated Hospital of Soochow University, Suzhou, Jiangsu 215123, P.R. China.
| | - Yao-Hua Song
- Cyrus Tang Hematology Center, Jiangsu Institute of Hematology, First Affiliated Hospital, Collaborative Innovation Center of Hematology, Soochow University, Suzhou, P.R. China.
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96
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Vallejo J, Spence M, Cheng AL, Brotto L, Edens NK, Garvey SM, Brotto M. Cellular and Physiological Effects of Dietary Supplementation with β-Hydroxy-β-Methylbutyrate (HMB) and β-Alanine in Late Middle-Aged Mice. PLoS One 2016; 11:e0150066. [PMID: 26953693 PMCID: PMC4783107 DOI: 10.1371/journal.pone.0150066] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2015] [Accepted: 02/09/2016] [Indexed: 12/22/2022] Open
Abstract
There is growing evidence that severe decline of skeletal muscle mass and function with age may be mitigated by exercise and dietary supplementation with protein and amino acid ingredient technologies. The purposes of this study were to examine the effects of the leucine catabolite, beta-hydroxy-beta-methylbutyrate (HMB), in C2C12 myoblasts and myotubes, and to investigate the effects of dietary supplementation with HMB, the amino acid β-alanine and the combination thereof, on muscle contractility in a preclinical model of pre-sarcopenia. In C2C12 myotubes, HMB enhanced sarcoplasmic reticulum (SR) calcium release beyond vehicle control in the presence of all SR agonists tested (KCl, P<0.01; caffeine, P = 0.03; ionomycin, P = 0.03). HMB also improved C2C12 myoblast viability (25 μM HMB, P = 0.03) and increased proliferation (25 μM HMB, P = 0.04; 125 μM HMB, P<0.01). Furthermore, an ex vivo muscle contractility study was performed on EDL and soleus muscle from 19 month old, male C57BL/6nTac mice. For 8 weeks, mice were fed control AIN-93M diet, diet with HMB, diet with β-alanine, or diet with HMB and β-alanine. In β-alanine fed mice, EDL muscle showed a 7% increase in maximum absolute force compared to the control diet (202 ± 3vs. 188± 5 mN, P = 0.02). At submaximal frequency of stimulation (20 Hz), EDL from mice fed HMB plus β-alanine showed an 11% increase in absolute force (88.6 ± 2.2 vs. 79.8 ± 2.4 mN, P = 0.025) and a 13% increase in specific force (12.2 ± 0.4 vs. 10.8 ± 0.4 N/cm2, P = 0.021). Also in EDL muscle, β-alanine increased the rate of force development at all frequencies tested (P<0.025), while HMB reduced the time to reach peak contractile force (TTP), with a significant effect at 80 Hz (P = 0.0156). In soleus muscle, all experimental diets were associated with a decrease in TTP, compared to control diet. Our findings highlight beneficial effects of HMB and β-alanine supplementation on skeletal muscle function in aging mice.
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Affiliation(s)
- Julian Vallejo
- Muscle Biology Research Group, School of Nursing & Health Studies, University of Missouri-Kansas City, Kansas City, Missouri, United States of America
| | - Madoka Spence
- Muscle Biology Research Group, School of Nursing & Health Studies, University of Missouri-Kansas City, Kansas City, Missouri, United States of America
| | - An-Lin Cheng
- Muscle Biology Research Group, School of Nursing & Health Studies, University of Missouri-Kansas City, Kansas City, Missouri, United States of America
| | - Leticia Brotto
- Muscle Biology Research Group, School of Nursing & Health Studies, University of Missouri-Kansas City, Kansas City, Missouri, United States of America
| | - Neile K. Edens
- Abbott Nutrition R&D, Columbus, Ohio, United States of America
| | - Sean M. Garvey
- Abbott Nutrition R&D, Columbus, Ohio, United States of America
- * E-mail: (MB); (SG)
| | - Marco Brotto
- Muscle Biology Research Group, School of Nursing & Health Studies, University of Missouri-Kansas City, Kansas City, Missouri, United States of America
- * E-mail: (MB); (SG)
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