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Villani KR, Zhong R, Henley-Beasley CS, Rastelli G, Boncompagni S, Barton ER, Wei-LaPierre L. Loss of calpain 3 dysregulates store-operated calcium entry and its exercise response in mice. bioRxiv 2024:2024.01.12.575391. [PMID: 38293127 PMCID: PMC10827051 DOI: 10.1101/2024.01.12.575391] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2024]
Abstract
Limb-Girdle Muscular Dystrophy 2A (LGMD2A) is caused by mutations in the CAPN3 gene encoding Calpain 3, a skeletal-muscle specific, Ca2+-dependent protease. Localization of Calpain 3 within the triad suggests it contributes to Ca2+ homeostasis. Through live-cell Ca2+ measurements, muscle mechanics, immunofluorescence, and electron microscopy (EM) in Capn3 deficient (C3KO) and wildtype (WT) mice, we determined if loss of Calpain 3 altered Store-Operated Calcium Entry (SOCE) activity. Direct Ca2+ influx measurements revealed loss of Capn3 elicits elevated resting SOCE and increased resting cytosolic Ca2+, supported by high incidence of calcium entry units (CEUs) observed by EM. C3KO and WT mice were subjected to a single bout of treadmill running to elicit SOCE. Within 1HR post-treadmill running, C3KO mice exhibited diminished force production in extensor digitorum longus muscles and a greater decay of Ca2+ transients in flexor digitorum brevis muscle fibers during repetitive stimulation. Striking evidence for impaired exercise-induced SOCE activation in C3KO mice included poor colocalization of key SOCE proteins, stromal-interacting molecule 1 (STIM1) and ORAI1, combined with disappearance of CEUs in C3KO muscles. These results demonstrate that Calpain 3 is a key regulator of SOCE in skeletal muscle and identify SOCE dysregulation as a contributing factor to LGMD2A pathology.
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Affiliation(s)
- Katelyn R. Villani
- Department of Applied Physiology and Kinesiology, College of Health and Human Performance, University of Florida, FL, USA
| | - Renjia Zhong
- Department of Applied Physiology and Kinesiology, College of Health and Human Performance, University of Florida, FL, USA
- Department of Emergency Medicine, the First Affiliated Hospital of China Medical University, Shenyang, Liaoning, China
| | - C. Spencer Henley-Beasley
- Department of Applied Physiology and Kinesiology, College of Health and Human Performance, University of Florida, FL, USA
- Myology Institute, University of Florida, FL, USA
| | - Giorgia Rastelli
- Center for Advanced Studies and Technology and Department of Neuroscience, Imaging and Clinical Sciences, University G. d’Annunzio of Chieti–Pescara, Chieti, Italy
| | - Simona Boncompagni
- Center for Advanced Studies and Technology and Department of Neuroscience, Imaging and Clinical Sciences, University G. d’Annunzio of Chieti–Pescara, Chieti, Italy
| | - Elisabeth R. Barton
- Department of Applied Physiology and Kinesiology, College of Health and Human Performance, University of Florida, FL, USA
- Myology Institute, University of Florida, FL, USA
| | - Lan Wei-LaPierre
- Department of Applied Physiology and Kinesiology, College of Health and Human Performance, University of Florida, FL, USA
- Myology Institute, University of Florida, FL, USA
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LaManna L, Chou CH, Lei H, Barton ER, Maliga P. Chloroplast transformation for bioencapsulation and oral delivery using the immunoglobulin G fragment crystallizable (Fc) domain. Sci Rep 2023; 13:18916. [PMID: 37919321 PMCID: PMC10622566 DOI: 10.1038/s41598-023-45698-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Accepted: 10/23/2023] [Indexed: 11/04/2023] Open
Abstract
Proinsulin Like Growth Factor I (prolGF-I) and myostatin (Mstn) regulate muscle regeneration and mass when intravenously delivered. We tested if chloroplast bioencapsulated forms of these proteins may serve as a non-invasive means of drug delivery through the digestive system. We created tobacco (Nicotiana tabacum) plants carrying GFP-Fc1, proIGF-I-Fc1, and Mstn-Fc1 fusion genes, in which fusion with the immunoglobulin G Fc domain improved both protein stability and absorption in the small intestine. No transplastomic plants were obtained with the Mstn-Fc1 gene, suggesting that the protein is toxic to plant cells. proIGF-I-Fc1 protein levels were too low to enable in vivo testing. However, GFP-Fc1 accumulated at a high level, enabling evaluation of chloroplast-made Fc fusion proteins for oral delivery. Tobacco leaves were lyophilized for testing in a mouse system. We report that the orally administered GFP-Fc1 fusion protein (5.45 µg/g GFP-Fc1) has been taken up by the intestinal epithelium cells, evidenced by confocal microscopy. GFP-Fc1 subsequently entered the circulation where it was detected by ELISA. Data reported here confirm that chloroplast expression and oral administration of lyophilized leaves is a potential delivery system of therapeutic proteins fused with Fc1, with the advantage that the proteins may be stored at room temperature.
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Affiliation(s)
- Lisa LaManna
- Waksman Institute of Microbiology, Rutgers University, Piscataway, NJ, 08854, USA
| | - Chih-Hsuan Chou
- Department of Applied Physiology and Kinesiology, College of Health and Human Performance, University of Florida, Gainesville, FL, 32611, USA
| | - Hanqin Lei
- Department of Applied Physiology and Kinesiology, College of Health and Human Performance, University of Florida, Gainesville, FL, 32611, USA
| | - Elisabeth R Barton
- Department of Applied Physiology and Kinesiology, College of Health and Human Performance, University of Florida, Gainesville, FL, 32611, USA.
| | - Pal Maliga
- Waksman Institute of Microbiology, Rutgers University, Piscataway, NJ, 08854, USA.
- Department of Plant Biology, Rutgers University, New Brunswick, NJ, 08901, USA.
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Chou CH, Barton ER. Phosphorylation of AMPKα at Ser485/491 Is Dependent on Muscle Contraction and Not Muscle-Specific IGF-I Overexpression. Int J Mol Sci 2023; 24:11950. [PMID: 37569325 PMCID: PMC10418898 DOI: 10.3390/ijms241511950] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Revised: 07/20/2023] [Accepted: 07/21/2023] [Indexed: 08/13/2023] Open
Abstract
Glucose is an important fuel for highly active skeletal muscles. Increased adenosine monophosphate (AMP)/adenosine triphosphate (ATP) ratios during repetitive contractions trigger AMP-activated protein kinase (AMPK), indicated by phosphorylation of AMPKαThr172, which promotes glucose uptake to support heightened energy needs, but it also suppresses anabolic processes. Inhibition of AMPK can occur by protein kinase B (AKT)-mediated phosphorylation of AMPKαSer485/491, releasing its brake on growth. The influence of insulin-like growth factor I (IGF-I) on glucose uptake and its interplay with AMPK activation is not well understood. Thus, the goal of this study was to determine if increased muscle IGF-I altered AMPKα phosphorylation and activity during muscle contraction. Adult male mice harboring the rat Igf1a cDNA regulated by the fast myosin light chain promoter (mIgf1+/+) and wildtype littermates (WT) were used in the study. mIgf1+/+ mice had enhanced glucose tolerance and insulin-stimulated glucose uptake, but similar exercise capacity. Fatiguing stimulations of extensor digitorum longus (EDL) muscles resulted in upregulated AMPKα phosphorylation at both Thr172 and Ser485/491 in WT and mIgf1+/+ muscles. No differences in the phosphorylation response of the downstream AMPK target TBC1D1 were observed, but phosphorylation of raptor was significantly higher only in WT muscles. Further, total raptor content was elevated in mIgf1+/+ muscles. The results show that high muscle IGF-I can enhance glucose uptake under resting conditions; however, in contracting muscle, it is not sufficient to inhibit AMPK activity.
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Affiliation(s)
- Chih-Hsuan Chou
- Applied Physiology & Kinesiology, College of Health and Human Performance, University of Florida, Gainesville, FL 32611, USA;
- Biomedical Sciences, College of Veterinary Medicine, University of Missouri, Columbia, MO 65211, USA
| | - Elisabeth R. Barton
- Applied Physiology & Kinesiology, College of Health and Human Performance, University of Florida, Gainesville, FL 32611, USA;
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LaManna L, Chou CH, Lei H, Barton ER, Maliga P. Chloroplast transformation for bioencapsulation and oral delivery using the immunoglobulin G fragment crystallizable (Fc) domain. Res Sq 2023:rs.3.rs-3073879. [PMID: 37546919 PMCID: PMC10402193 DOI: 10.21203/rs.3.rs-3073879/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/08/2023]
Abstract
Proinsulin Like Growth Factor (prolGF1) and myostatin (Mstn) regulate muscle regeneration when intravenously delivered. We set out to test if chloroplast bioencapsulated forms of these proteins may serve as a non-invasive means of drug delivery through the digestive system. We created tobacco (Nicotiana tabacum) plants carrying GFP-Fc1, proIGF-I-Fc1, and Mstn-Fc1 fusion genes, in which fusion with the immunoglobulin G Fc domain improved both protein stability and absorption in the small intestine. No transplastomic plants were obtained with the Mstn-Fc1 gene, suggesting that the protein is toxic to plant cells. proIGF-I-Fc1 protein levels were too law to enable in vivo testing. However, GFP-Fc1 accumulated at a high level, enabling evaluation of chloroplast-made Fc fusion proteins for oral delivery. Tobacco leaves were lyophilized for testing in a mouse system. We report that the orally administered GFP-Fc fusion protein (5.45 μg/g GFP-Fc) has been taken up by the intestinal epithelium cells, evidenced by confocal microscopy. GFP-Fc subsequently entered the circulation where it was detected by ELISA. Data reported here confirm that chloroplast expression and oral administration of lyophilized leaves is a potential delivery system of therapeutic proteins fused with Fc, with the advantage that the proteins may be stored at room temperature.
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Affiliation(s)
- Lisa LaManna
- Waksman Institute of Microbiology, Rutgers University, Piscataway, NJ 08854, USA
| | - Chih-Hsuan Chou
- Department of Applied Physiology & Kinesiology, University of Florida, College of Health and Human Performance, Gainesville, FL, 32611, USA
| | - Hanqin Lei
- Department of Applied Physiology & Kinesiology, University of Florida, College of Health and Human Performance, Gainesville, FL, 32611, USA
| | - Elisabeth R. Barton
- Department of Applied Physiology & Kinesiology, University of Florida, College of Health and Human Performance, Gainesville, FL, 32611, USA
| | - Pal Maliga
- Waksman Institute of Microbiology, Rutgers University, Piscataway, NJ 08854, USA
- Department of Plant Biology, Rutgers University, New Brunswick, NJ 08901, USA
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Russell AJ, DuVall M, Barthel B, Qian Y, Peter AK, Newell-Stamper BL, Hunt K, Lehman SJ, Madden MR, Schlachter ST, Robertson BD, Van Deusen A, Rodriguez HM, Vera CD, Su Y, Claflin DR, Brooks SV, Nghiem PP, Rutledge A, Juehne TI, Yu J, Barton ER, Luo YE, Patsalos A, Nagy L, Sweeney HL, Leinwand LA, Koch K. Modulating fast skeletal muscle contraction protects skeletal muscle in animal models of Duchenne muscular dystrophy. J Clin Invest 2023; 133:153837. [PMID: 36995778 PMCID: PMC10178848 DOI: 10.1172/jci153837] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Accepted: 03/24/2023] [Indexed: 03/31/2023] Open
Abstract
Duchenne muscular dystrophy (DMD) is a lethal muscle disease caused by absence of the protein dystrophin, which acts as a structural link between the basal lamina and contractile machinery to stabilize muscle membranes from mechanical stress. In DMD, mechanical stress leads to exaggerated membrane injury and fiber breakdown, with fast fibers being the most susceptible to damage. A major contributor to this injury is muscle contraction, controlled by the motor protein myosin. However, the relationship between how muscle contraction and fast muscle fiber damage contribute to the pathophysiology of DMD has not been well characterized. We explored the role of fast skeletal muscle contraction in DMD with a novel, selective, orally active inhibitor of fast skeletal muscle myosin, EDG-5506. Surprisingly, even modest decreases of contraction (<15%) were sufficient to protect skeletal muscles in dystrophic mdx mice from stress injury. Longer-term treatment also decreased muscle fibrosis in key disease-implicated tissues. Importantly, therapeutic levels of myosin inhibition with EDG-5506 did not detrimentally affect strength or coordination. Finally, in dystrophic dogs, EDG-5506 reversibly reduced circulating muscle injury biomarkers and increased habitual activity. This unexpected biology may represent an important alternative treatment strategy for Duchenne and related myopathies.
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Affiliation(s)
- Alan J Russell
- BioFrontiers Institute, Edgewise Therapeutics, Boulder, United States of America
| | - Mike DuVall
- BioFrontiers Institute, Edgewise Therapeutics, Boulder, United States of America
| | - Benjamin Barthel
- BioFrontiers Institute, Edgewise Therapeutics, Boulder, United States of America
| | - Ying Qian
- BioFrontiers Institute, Edgewise Therapeutics, Boulder, United States of America
| | - Angela K Peter
- BioFrontiers Institute, Edgewise Therapeutics, Boulder, United States of America
| | | | - Kevin Hunt
- BioFrontiers Institute, Edgewise Therapeutics, Boulder, United States of America
| | - Sarah J Lehman
- BioFrontiers Institute, Edgewise Therapeutics, Boulder, United States of America
| | - Molly R Madden
- BioFrontiers Institute, Edgewise Therapeutics, Boulder, United States of America
| | - Stephen T Schlachter
- BioFrontiers Institute, Edgewise Therapeutics, Boulder, United States of America
| | - Benjamin D Robertson
- BioFrontiers Institute, Edgewise Therapeutics, Boulder, United States of America
| | - Ashleigh Van Deusen
- BioFrontiers Institute, Edgewise Therapeutics, Boulder, United States of America
| | | | - Carlos D Vera
- Department of Molecular, Cellular, and Developmental Biology, University of Colorado, Boulder, United States of America
| | - Yu Su
- Molecular and Integrative Physiology, The University of Michigan, Ann Arbor, United States of America
| | - Dennis R Claflin
- Department of Surgery, Section of Plastic Surgery, The University of Michigan, Ann Arbor, United States of America
| | - Susan V Brooks
- Molecular and Integrative Physiology, The University of Michigan, Ann Arbor, United States of America
| | - Peter P Nghiem
- College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, United States of America
| | - Alexis Rutledge
- College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, United States of America
| | - Twlya I Juehne
- Genome Technology Access Center, Department of Genetics, Washington University in Saint Louis, School of Medicine, St. Louis, United States of America
| | - Jinsheng Yu
- Genome Technology Access Center, Department of Genetics, Washington University in Saint Louis, School of Medicine, St. Louis, United States of America
| | - Elisabeth R Barton
- Department of Applied Physiology and Kinesiology and Myology Institute, University of Florida College of Health and Human Performance, Gainesville, United States of America
| | - Yangyi E Luo
- Department of Applied Physiology and Kinesiology and Myology Institute, University of Florida College of Health and Human Performance, Gainesville, United States of America
| | - Andreas Patsalos
- Departments of Medicine and Biological Chemistry, IFBR, John Hopkins University Medical School, St. Petersburg, United States of America
| | - Laszlo Nagy
- Departments of Medicine and Biological Chemistry, IFBR, John Hopkins University Medical School, St. Petersburg, United States of America
| | - H Lee Sweeney
- Department of Pharmacology & Therapeutics and Myology Institute, University of Florida College of Medicine, Gainesville, United States of America
| | - Leslie A Leinwand
- Department of Molecular, Cellular, and Developmental Biology, University of Colorado, Boulder, United States of America
| | - Kevin Koch
- BioFrontiers Institute, Edgewise Therapeutics, Boulder, United States of America
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Khattri RB, Puglise J, Ryan TE, Walter GA, Merritt ME, Barton ER. Isolated murine skeletal muscles utilize pyruvate over glucose for oxidation. Metabolomics 2022; 18:105. [PMID: 36480060 PMCID: PMC9732067 DOI: 10.1007/s11306-022-01948-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Accepted: 10/29/2022] [Indexed: 12/13/2022]
Abstract
INTRODUCTION Fuel sources for skeletal muscle tissue include carbohydrates and fatty acids, and utilization depends upon fiber type, workload, and substrate availability. The use of isotopically labeled substrate tracers combined with nuclear magnetic resonance (NMR) enables a deeper examination of not only utilization of substrates by a given tissue, but also their contribution to tricarboxylic acid (TCA) cycle intermediates. OBJECTIVES The goal of this study was to determine the differential utilization of substrates in isolated murine skeletal muscle, and to evaluate how isopotomer anlaysis provided insight into skeletal muscle metabolism. METHODS Isolated C57BL/6 mouse hind limb muscles were incubated in oxygenated solution containing uniformly labeled 13C6 glucose, 13C3 pyruvate, or 13C2 acetate at room temperature. Isotopomer analysis of 13C labeled glutamate was performed on pooled extracts of isolated soleus and extensor digitorum longus (EDL) muscles. RESULTS Pyruvate and acetate were more avidly consumed than glucose with resultant increases in glutamate labeling in both muscle groups. Glucose incubation resulted in glutamate labeling, but with high anaplerotic flux in contrast to the labeling by pyruvate. Muscle fiber type distinctions were evident by differences in lactate enrichment and extent of substrate oxidation. CONCLUSION Isotope tracing experiments in isolated muscles reveal that pyruvate and acetate are avidly oxidized by isolated soleus and EDL muscles, whereas glucose labeling of glutamate is accompanied by high anaplerotic flux. We believe our results may set the stage for future examination of metabolic signatures of skeletal muscles from pre-clinical models of aging, type-2 diabetes and neuromuscular disease.
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Affiliation(s)
- Ram B Khattri
- Department of Applied Physiology and Kinesiology, College of Health & Human Performance, University of Florida, 124 Florida Gym, 1864 Stadium Road, Gainesville, FL, 32611, USA
| | - Jason Puglise
- Department of Applied Physiology and Kinesiology, College of Health & Human Performance, University of Florida, 124 Florida Gym, 1864 Stadium Road, Gainesville, FL, 32611, USA
| | - Terence E Ryan
- Department of Applied Physiology and Kinesiology, College of Health & Human Performance, University of Florida, 124 Florida Gym, 1864 Stadium Road, Gainesville, FL, 32611, USA
- Myology Institute, University of Florida, Gainesville, USA
- Center for Exercise Science, University of Florida, Gainesville, FL, USA
| | - Glenn A Walter
- Department of Physiology and Functional Genomics, University of Florida, Gainesville, USA
- Myology Institute, University of Florida, Gainesville, USA
| | - Matthew E Merritt
- Department of Biochemistry and Molecular Biology, University of Florida, Gainesville, USA
| | - Elisabeth R Barton
- Department of Applied Physiology and Kinesiology, College of Health & Human Performance, University of Florida, 124 Florida Gym, 1864 Stadium Road, Gainesville, FL, 32611, USA.
- Myology Institute, University of Florida, Gainesville, USA.
- Center for Exercise Science, University of Florida, Gainesville, FL, USA.
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Smith TC, Vasilakos G, Shaffer SA, Puglise JM, Chou CH, Barton ER, Luna EJ. Novel γ-sarcoglycan interactors in murine muscle membranes. Skelet Muscle 2022; 12:2. [PMID: 35065666 PMCID: PMC8783446 DOI: 10.1186/s13395-021-00285-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Accepted: 12/15/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The sarcoglycan complex (SC) is part of a network that links the striated muscle cytoskeleton to the basal lamina across the sarcolemma. The SC coordinates changes in phosphorylation and Ca++-flux during mechanical deformation, and these processes are disrupted with loss-of-function mutations in gamma-sarcoglycan (Sgcg) that cause Limb girdle muscular dystrophy 2C/R5. METHODS To gain insight into how the SC mediates mechano-signaling in muscle, we utilized LC-MS/MS proteomics of SC-associated proteins in immunoprecipitates from enriched sarcolemmal fractions. Criteria for inclusion were co-immunoprecipitation with anti-Sgcg from C57BL/6 control muscle and under-representation in parallel experiments with Sgcg-null muscle and with non-specific IgG. Validation of interaction was performed in co-expression experiments in human RH30 rhabdomyosarcoma cells. RESULTS We identified 19 candidates as direct or indirect interactors for Sgcg, including the other 3 SC proteins. Novel potential interactors included protein-phosphatase-1-catalytic-subunit-beta (Ppp1cb, PP1b) and Na+-K+-Cl--co-transporter NKCC1 (SLC12A2). NKCC1 co-localized with Sgcg after co-expression in human RH30 rhabdomyosarcoma cells, and its cytosolic domains depleted Sgcg from cell lysates upon immunoprecipitation and co-localized with Sgcg after detergent permeabilization. NKCC1 localized in proximity to the dystrophin complex at costameres in vivo. Bumetanide inhibition of NKCC1 cotransporter activity in isolated muscles reduced SC-dependent, strain-induced increases in phosphorylation of extracellular signal-regulated kinases 1 and 2 (ERK1/2). In silico analysis suggests that candidate SC interactors may cross-talk with survival signaling pathways, including p53, estrogen receptor, and TRIM25. CONCLUSIONS Results support that NKCC1 is a new SC-associated signaling protein. Moreover, the identities of other candidate SC interactors suggest ways by which the SC and NKCC1, along with other Sgcg interactors such as the membrane-cytoskeleton linker archvillin, may regulate kinase- and Ca++-mediated survival signaling in skeletal muscle.
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Affiliation(s)
- Tara C Smith
- Department of Radiology, Division of Cell Biology & Imaging, University of Massachusetts Medical School, Worcester, MA, USA
| | - Georgios Vasilakos
- Applied Physiology & Kinesiology, College of Health & Human Performance, University of Florida, Gainesville, FL, USA
| | - Scott A Shaffer
- Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA, USA.,Mass Spectrometry Facility, University of Massachusetts Medical School, Shrewsbury, MA, USA
| | - Jason M Puglise
- Applied Physiology & Kinesiology, College of Health & Human Performance, University of Florida, Gainesville, FL, USA
| | - Chih-Hsuan Chou
- Applied Physiology & Kinesiology, College of Health & Human Performance, University of Florida, Gainesville, FL, USA
| | - Elisabeth R Barton
- Applied Physiology & Kinesiology, College of Health & Human Performance, University of Florida, Gainesville, FL, USA.
| | - Elizabeth J Luna
- Department of Radiology, Division of Cell Biology & Imaging, University of Massachusetts Medical School, Worcester, MA, USA.
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Spradlin RA, Vassilakos G, Matheny MK, Jones NC, Goldman JL, Lei H, Barton ER. Deletion of muscle Igf1 exacerbates disuse atrophy weakness in mice. J Appl Physiol (1985) 2021; 131:881-894. [PMID: 34292789 DOI: 10.1152/japplphysiol.00090.2021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Muscle atrophy occurs as a result of prolonged periods of reduced mechanical stimulation associated with injury or disease. The growth hormone/insulin-like growth factor-1 (GH/IGF-1) axis and load sensing pathways can both aid in recovery from disuse through their shared downstream signaling, but their relative contributions to these processes are not fully understood. The goal of this study was to determine whether reduced muscle IGF-1 altered the response to disuse and reloading. Adult male mice with inducible muscle-specific IGF-1 deletion (MID) induced 1 wk before suspension and age-matched controls (CON) were subjected to hindlimb suspension and reloading. Analysis of muscle force, morphology, gene expression, signaling, and tissue weights was performed in nonsuspended (NS) mice, and those suspended for 7 days or reloaded following suspension for 3, 7, and 14 days. MID mice displayed diminished IGF-1 protein levels and muscle atrophy before suspension. Muscles from suspended CON mice displayed a similar extent of atrophy and depletion of IGF-1, yet combined loss of load and IGF-1 was not additive with respect to muscle mass. In contrast, soleus force generation capacity was diminished to the greatest extent when both suspension and IGF-1 deletion occurred. Recovery of mass, force, and gene expression patterns following suspension were similar in CON and MID mice, even though IGF-1 levels increased only in muscles from CON mice. Diminished strength in disuse atrophy is exacerbated with the loss of muscle IGF-1 production, whereas recovery of mass and strength upon reloading can occur even IGF-1 is low.NEW & NOTEWORTHY A mouse model with skeletal muscle-specific inducible deletion of Igf1 was used to address the importance of this growth factor for the consequences of disuse atrophy. Rapid and equivalent loss of IGF-I and mass occurred with deletion or disuse. Decrements in strength were most severe with combined loss of load and IGF-1. Return of mass and strength upon reloading was independent of IGF-1.
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Affiliation(s)
- Ray A Spradlin
- Department of Applied Physiology and Kinesiology, College of Health and Human Performance, University of Florida, Gainesville, Florida
| | - Georgios Vassilakos
- Department of Applied Physiology and Kinesiology, College of Health and Human Performance, University of Florida, Gainesville, Florida
| | - Michael K Matheny
- Department of Pharmacology and Therapeutics, College of Medicine, University of Florida, Gainesville, Florida
| | - Nathan C Jones
- Department of Applied Physiology and Kinesiology, College of Health and Human Performance, University of Florida, Gainesville, Florida
| | - Jessica L Goldman
- Department of Applied Physiology and Kinesiology, College of Health and Human Performance, University of Florida, Gainesville, Florida
| | - Hanqin Lei
- Department of Applied Physiology and Kinesiology, College of Health and Human Performance, University of Florida, Gainesville, Florida
| | - Elisabeth R Barton
- Department of Applied Physiology and Kinesiology, College of Health and Human Performance, University of Florida, Gainesville, Florida
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Kok HJ, Crowder CN, Koo Min Chee L, Choi HY, Lin N, Barton ER. Muscle insulin-like growth factor-I modulates murine craniofacial bone growth. Eur Cell Mater 2021; 42:72-89. [PMID: 34279041 DOI: 10.22203/ecm.v042a06] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Insulin-like growth factor I (IGF-I) is essential for muscle and bone development and a primary mediator of growth hormone (GH) actions. While studies have elucidated the importance of IGF-I specifically in muscle or bone development, few studies to date have evaluated the relationship between muscle and bone modulated by IGF-I in vivo, during post-natal growth. Mice with muscle-specific IGF-I overexpression (mIgf1+/+) were utilised to determine IGF-I- and muscle-mass-dependent effects on craniofacial skeleton development during post-natal growth. mIgf1+/+ mice displayed accelerated craniofacial bone growth when compared to wild-type animals. Virus-mediated expression of IGF-I targeting the masseter was performed to determine if post-natal modulation of IGF-I altered mandibular structures. Increased IGF-I in the masseter affected the mandibular base plane angle in a lateral manner, increasing the width of the mandible. At the cellular level, increased muscle IGF-I also accelerated cartilage thickness in the mandibular condyle. Importantly, mandibular length changes associated with increased IGF-I were not present in mice with genetic inhibition of muscle IGF-I receptor activity. These results demonstrated that muscle IGF-I could indirectly affect craniofacial growth through IGF-I-dependent increases in muscle hypertrophy. These findings have clinical implications when considering IGF-I as a therapeutic strategy for craniofacial disorders.
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Affiliation(s)
| | | | | | | | | | - E R Barton
- Applied Physiology and Kinesiology, College of Health and Human Performance, University of Florida, 1864 Stadium Road, Gainesville, FL 32611,
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Laitano O, Pindado J, Valera I, Spradlin RA, Murray KO, Villani KR, Alzahrani JM, Ryan TE, Efron PA, Ferreira LF, Barton ER, Clanton TL. The impact of hindlimb disuse on sepsis-induced myopathy in mice. Physiol Rep 2021; 9:e14979. [PMID: 34309237 PMCID: PMC8311555 DOI: 10.14814/phy2.14979] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Accepted: 06/29/2021] [Indexed: 11/24/2022] Open
Abstract
Sepsis induces a myopathy characterized by loss of muscle mass and weakness. Septic patients undergo prolonged periods of limb muscle disuse due to bed rest. The contribution of limb muscle disuse to the myopathy phenotype remains poorly described. To characterize sepsis-induced myopathy with hindlimb disuse, we combined the classic sepsis model via cecal ligation and puncture (CLP) with the disuse model of hindlimb suspension (HLS) in mice. Male C57bl/6j mice underwent CLP or SHAM surgeries. Four days after surgeries, mice underwent HLS or normal ambulation (NA) for 7 days. Soleus (SOL) and extensor digitorum longus (EDL) were dissected for in vitro muscle mechanics, morphological, and histological assessments. In SOL muscles, both CLP+NA and SHAM+HLS conditions elicited ~20% reduction in specific force (p < 0.05). When combined, CLP+HLS elicited ~35% decrease in specific force (p < 0.05). Loss of maximal specific force (~8%) was evident in EDL muscles only in CLP+HLS mice (p < 0.05). CLP+HLS reduced muscle fiber cross-sectional area (CSA) and mass in SOL (p < 0.05). In EDL muscles, CLP+HLS decreased absolute mass to a smaller extent (p < 0.05) with no changes in CSA. Immunohistochemistry revealed substantial myeloid cell infiltration (CD68+) in SOL, but not in EDL muscles, of CLP+HLS mice (p < 0.05). Combining CLP with HLS is a feasible model to study sepsis-induced myopathy in mice. Hindlimb disuse combined with sepsis induced muscle dysfunction and immune cell infiltration in a muscle dependent manner. These findings highlight the importance of rehabilitative interventions in septic hosts to prevent muscle disuse and help attenuate the myopathy.
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Affiliation(s)
- Orlando Laitano
- Department of Nutrition and Integrative PhysiologyCollege of Health and Human SciencesFlorida State UniversityTallahasseeFLUSA
| | - Jose Pindado
- Department of Nutrition and Integrative PhysiologyCollege of Health and Human SciencesFlorida State UniversityTallahasseeFLUSA
| | - Isela Valera
- Department of Nutrition and Integrative PhysiologyCollege of Health and Human SciencesFlorida State UniversityTallahasseeFLUSA
| | - Ray A. Spradlin
- Department of Applied Physiology and KinesiologyCollege of Health and Human PerformanceUniversity of FloridaGainesvilleFLUSA
| | - Kevin O. Murray
- Department of Applied Physiology and KinesiologyCollege of Health and Human PerformanceUniversity of FloridaGainesvilleFLUSA
| | - Katelyn R. Villani
- Department of Applied Physiology and KinesiologyCollege of Health and Human PerformanceUniversity of FloridaGainesvilleFLUSA
| | - Jamal M. Alzahrani
- Department of Applied Physiology and KinesiologyCollege of Health and Human PerformanceUniversity of FloridaGainesvilleFLUSA
| | - Terence E. Ryan
- Department of Applied Physiology and KinesiologyCollege of Health and Human PerformanceUniversity of FloridaGainesvilleFLUSA
| | - Philip A. Efron
- Department of SurgeryCollege of MedicineUniversity of FloridaGainesvilleFLUSA
| | - Leonardo F. Ferreira
- Department of Applied Physiology and KinesiologyCollege of Health and Human PerformanceUniversity of FloridaGainesvilleFLUSA
| | - Elisabeth R. Barton
- Department of Applied Physiology and KinesiologyCollege of Health and Human PerformanceUniversity of FloridaGainesvilleFLUSA
| | - Thomas L. Clanton
- Department of Applied Physiology and KinesiologyCollege of Health and Human PerformanceUniversity of FloridaGainesvilleFLUSA
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11
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Kok HJ, Barton ER. Actions and interactions of IGF-I and MMPs during muscle regeneration. Semin Cell Dev Biol 2021; 119:11-22. [PMID: 33962867 DOI: 10.1016/j.semcdb.2021.04.018] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2021] [Revised: 04/04/2021] [Accepted: 04/19/2021] [Indexed: 12/11/2022]
Abstract
Muscle regeneration requires the coordination of several factors to mobilize satellite cells and macrophages, remodel the extracellular matrix surrounding muscle fibers, and repair existing and/or form new muscle fibers. In this review, we focus on insulin-like growth factor I and the matrix metalloproteinases, which are secreted proteins that act on cells and the matrix to resolve damage. While their actions appear independent, their interactions occur at the transcriptional and post-translational levels to promote feed-forward activation of each other. Together, these proteins assist at virtually every step of the repair process, and contribute significantly to muscle regenerative capacity.
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Affiliation(s)
- Hui Jean Kok
- Applied Physiology & Kinesiology, College of Health and Human Performance, University of Florida, 1864 Stadium Road, Gainesville, FL 32611, USA
| | - Elisabeth R Barton
- Applied Physiology & Kinesiology, College of Health and Human Performance, University of Florida, 1864 Stadium Road, Gainesville, FL 32611, USA.
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12
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Miguez PA, Tuin SA, Robinson AG, Belcher J, Jongwattanapisan P, Perley K, de Paiva Gonҫalves V, Hanifi A, Pleshko N, Barton ER. Hesperidin Promotes Osteogenesis and Modulates Collagen Matrix Organization and Mineralization In Vitro and In Vivo. Int J Mol Sci 2021; 22:3223. [PMID: 33810030 PMCID: PMC8004833 DOI: 10.3390/ijms22063223] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Revised: 03/10/2021] [Accepted: 03/18/2021] [Indexed: 12/01/2022] Open
Abstract
This study evaluated the direct effect of a phytochemical, hesperidin, on pre-osteoblast cell function as well as osteogenesis and collagen matrix quality, as there is little known about hesperidin's influence in mineralized tissue formation and regeneration. Hesperidin was added to a culture of MC3T3-E1 cells at various concentrations. Cell proliferation, viability, osteogenic gene expression and deposited collagen matrix analyses were performed. Treatment with hesperidin showed significant upregulation of osteogenic markers, particularly with lower doses. Mature and compact collagen fibrils in hesperidin-treated cultures were observed by picrosirius red staining (PSR), although a thinner matrix layer was present for the higher dose of hesperidin compared to osteogenic media alone. Fourier-transform infrared spectroscopy indicated a better mineral-to-matrix ratio and matrix distribution in cultures exposed to hesperidin and confirmed less collagen deposited with the 100-µM dose of hesperidin. In vivo, hesperidin combined with a suboptimal dose of bone morphogenetic protein 2 (BMP2) (dose unable to promote healing of a rat mandible critical-sized bone defect) in a collagenous scaffold promoted a well-controlled (not ectopic) pattern of bone formation as compared to a large dose of BMP2 (previously defined as optimal in healing the critical-sized defect, although of ectopic nature). PSR staining of newly formed bone demonstrated that hesperidin can promote maturation of bone organic matrix. Our findings show, for the first time, that hesperidin has a modulatory role in mineralized tissue formation via not only osteoblast cell differentiation but also matrix organization and matrix-to-mineral ratio and could be a potential adjunct in regenerative bone therapies.
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Affiliation(s)
- Patricia A. Miguez
- Division of Comprehensive Oral Health, School of Dentistry, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA;
| | - Stephen A. Tuin
- Oral and Craniofacial Health Sciences, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; (S.A.T.); (A.G.R.); (P.J.)
| | - Adam G. Robinson
- Oral and Craniofacial Health Sciences, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; (S.A.T.); (A.G.R.); (P.J.)
| | | | - Prapaporn Jongwattanapisan
- Oral and Craniofacial Health Sciences, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; (S.A.T.); (A.G.R.); (P.J.)
| | - Kimberly Perley
- Department of Periodontics, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA;
| | - Vinicius de Paiva Gonҫalves
- Division of Comprehensive Oral Health, School of Dentistry, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA;
| | - Arash Hanifi
- Department of Bioengineering, Temple University, Philadelphia, PA 19122, USA; (A.H.); (N.P.)
| | - Nancy Pleshko
- Department of Bioengineering, Temple University, Philadelphia, PA 19122, USA; (A.H.); (N.P.)
| | - Elisabeth R. Barton
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL 32611, USA;
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13
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Hunt LC, Schadeberg B, Stover J, Haugen B, Pagala V, Wang YD, Puglise J, Barton ER, Peng J, Demontis F. Antagonistic control of myofiber size and muscle protein quality control by the ubiquitin ligase UBR4 during aging. Nat Commun 2021; 12:1418. [PMID: 33658508 PMCID: PMC7930053 DOI: 10.1038/s41467-021-21738-8] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Accepted: 02/08/2021] [Indexed: 01/31/2023] Open
Abstract
Sarcopenia is a degenerative condition that consists in age-induced atrophy and functional decline of skeletal muscle cells (myofibers). A common hypothesis is that inducing myofiber hypertrophy should also reinstate myofiber contractile function but such model has not been extensively tested. Here, we find that the levels of the ubiquitin ligase UBR4 increase in skeletal muscle with aging, and that UBR4 increases the proteolytic activity of the proteasome. Importantly, muscle-specific UBR4 loss rescues age-associated myofiber atrophy in mice. However, UBR4 loss reduces the muscle specific force and accelerates the decline in muscle protein quality that occurs with aging in mice. Similarly, hypertrophic signaling induced via muscle-specific loss of UBR4/poe and of ESCRT members (HGS/Hrs, STAM, USP8) that degrade ubiquitinated membrane proteins compromises muscle function and shortens lifespan in Drosophila by reducing protein quality control. Altogether, these findings indicate that these ubiquitin ligases antithetically regulate myofiber size and muscle protein quality control.
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Affiliation(s)
- Liam C Hunt
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Bronwen Schadeberg
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Jared Stover
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Benard Haugen
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Vishwajeeth Pagala
- Department of Structural Biology, Center for Proteomics and Metabolomics, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Yong-Dong Wang
- Department of Cell and Molecular Biology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Jason Puglise
- College of Health & Human Performance Applied Physiology & Kinesiology, University of Florida, Gainesville, FL, USA
| | - Elisabeth R Barton
- College of Health & Human Performance Applied Physiology & Kinesiology, University of Florida, Gainesville, FL, USA
| | - Junmin Peng
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN, USA
- Department of Structural Biology, Center for Proteomics and Metabolomics, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Fabio Demontis
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN, USA.
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14
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Smith LR, Kok HJ, Zhang B, Chung D, Spradlin RA, Rakoczy KD, Lei H, Boesze-Battaglia K, Barton ER. Matrix Metalloproteinase 13 from Satellite Cells is Required for Efficient Muscle Growth and Regeneration. Cell Physiol Biochem 2020; 54:333-353. [PMID: 32275813 DOI: 10.33594/000000223] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/25/2020] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND/AIMS Cell migration and extracellular matrix remodeling underlie normal mammalian development and growth as well as pathologic tumor invasion. Skeletal muscle is no exception, where satellite cell migration replenishes nuclear content in damaged tissue and extracellular matrix reforms during regeneration. A key set of enzymes that regulate these processes are matrix metalloproteinases (MMP)s. The collagenase MMP-13 is transiently upregulated during muscle regeneration, but its contribution to damage resolution is unknown. The purpose of this work was to examine the importance of MMP-13 in muscle regeneration and growth in vivo and to delineate a satellite cell specific role for this collagenase. METHODS Mice with total and satellite cell specific Mmp13 deletion were utilized to determine the importance of MMP-13 for postnatal growth, regeneration after acute injury, and in chronic injury from a genetic cross with dystrophic (mdx) mice. We also evaluated insulin-like growth factor 1 (IGF-1) mediated hypertrophy in the presence and absence of MMP-13. We employed live-cell imaging and 3D migration measurements on primary myoblasts obtained from these animals. Outcome measures included muscle morphology and function. RESULTS Under basal conditions, Mmp13-/- mice did not exhibit histological or functional deficits in muscle. However, following acute injury, regeneration was impaired at 11 and 14 days post injury. Muscle hypertrophy caused by increased IGF-1 was blunted with minimal satellite cell incorporation in the absence of MMP-13. Mmp13-/- primary myoblasts displayed reduced migratory capacity in 2D and 3D, while maintaining normal proliferation and differentiation. Satellite cell specific deletion of MMP-13 recapitulated the effects of global MMP-13 ablation on muscle regeneration, growth and myoblast movement. CONCLUSION These results show that satellite cells provide an essential autocrine source of MMP-13, which not only regulates their migration, but also supports postnatal growth and resolution of acute damage.
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Affiliation(s)
- Lucas R Smith
- Anatomy and Cell Biology, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA, USA.,Neurobiology, Physiology & Behavior, Physical Medicine & Rehabilitation, University of California, Davis, CA, USA
| | - Hui Jean Kok
- Applied Physiology and Kinesiology, College of Health and Human Performance, University of Florida, Gainesville, FL, USA
| | - Boshi Zhang
- Anatomy and Cell Biology, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Du Chung
- Anatomy and Cell Biology, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Ray A Spradlin
- Applied Physiology and Kinesiology, College of Health and Human Performance, University of Florida, Gainesville, FL, USA
| | - Kyla D Rakoczy
- Applied Physiology and Kinesiology, College of Health and Human Performance, University of Florida, Gainesville, FL, USA
| | - Hanqin Lei
- Anatomy and Cell Biology, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA, USA.,Applied Physiology and Kinesiology, College of Health and Human Performance, University of Florida, Gainesville, FL, USA
| | | | - Elisabeth R Barton
- Anatomy and Cell Biology, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA, USA, .,Applied Physiology and Kinesiology, College of Health and Human Performance, University of Florida, Gainesville, FL, USA
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15
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Li F, Barton ER, Granzier H. Deleting nebulin's C-terminus reveals its importance to sarcomeric structure and function and is sufficient to invoke nemaline myopathy. Hum Mol Genet 2020; 28:1709-1725. [PMID: 30689900 DOI: 10.1093/hmg/ddz016] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Revised: 12/17/2018] [Accepted: 01/10/2019] [Indexed: 01/10/2023] Open
Abstract
Nebulin is a large skeletal muscle protein wound around the thin filaments, with its C-terminus embedded within the Z-disk and its N-terminus extending out toward the thin filament pointed end. While nebulin's C-terminus has been implicated in both sarcomeric structure and function as well as the development of nemaline myopathy, the contributions of this region remain largely unknown. Additionally, the C-terminus is reported to contribute to muscle hypertrophy via the IGF-1 growth pathway. To study the functions of nebulin's C-terminus, we generated a mouse model deleting the final two unique C-terminal domains, the serine-rich region (SRR) and the SH3 domain (NebΔ163-165). Homozygous NebΔ163-165 mice that survive past the neonatal stage exhibit a mild weight deficit. Characterization of these mice revealed that the truncation caused a moderate myopathy phenotype reminiscent of nemaline myopathy despite the majority of nebulin being localized properly in the thin filaments. This phenotype included muscle weight loss, changes in sarcomere structure, as well as a decrease in force production. Glutathione S-transferase (GST) pull-down experiments found novel binding partners with the SRR, several of which are associated with myopathies. While the C-terminus does not appear to be a limiting step in muscle growth, the IGF-1 growth pathway remained functional despite the deleted domains being proposed to be essential for IGF-1 mediated hypertrophy. The NebΔ163-165 mouse model emphasizes that nebulin's C-terminus is necessary for proper sarcomeric development and shows that its loss is sufficient to induce myopathy.
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Affiliation(s)
- Frank Li
- Department of Cellular and Molecular Medicine, University of Arizona, Tucson, Arizona, USA
| | - Elisabeth R Barton
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, Florida, USA
| | - Henk Granzier
- Department of Cellular and Molecular Medicine, University of Arizona, Tucson, Arizona, USA
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16
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Barton ER, Pham J, Brisson BK, Park S, Smith LR, Liu M, Tian Z, Hammers DW, Vassilakos G, Sweeney HL. Functional muscle hypertrophy by increased insulin-like growth factor 1 does not require dysferlin. Muscle Nerve 2019; 60:464-473. [PMID: 31323135 PMCID: PMC6771521 DOI: 10.1002/mus.26641] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2018] [Revised: 07/11/2019] [Accepted: 07/15/2019] [Indexed: 11/24/2022]
Abstract
INTRODUCTION Dysferlin loss-of-function mutations cause muscular dystrophy, accompanied by impaired membrane repair and muscle weakness. Growth promoting strategies including insulin-like growth factor 1 (IGF-1) could provide benefit but may cause strength loss or be ineffective. The objective of this study was to determine whether locally increased IGF-1 promotes functional muscle hypertrophy in dysferlin-null (Dysf-/- ) mice. METHODS Muscle-specific transgenic expression and postnatal viral delivery of Igf1 were used in Dysf-/- and control mice. Increased IGF-1 levels were confirmed by enzyme-linked immunosorbent assay. Testing for skeletal muscle mass and function was performed in male and female mice. RESULTS Muscle hypertrophy occurred in response to increased IGF-1 in mice with and without dysferlin. Male mice showed a more robust response compared with females. Increased IGF-1 did not cause loss of force per cross-sectional area in Dysf-/- muscles. DISCUSSION We conclude that increased local IGF-1 promotes functional hypertrophy when dysferlin is absent and reestablishes IGF-1 as a potential therapeutic for dysferlinopathies.
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Affiliation(s)
- Elisabeth R. Barton
- Anatomy and Cell Biology, School of Dental MedicineUniversity of PennsylvaniaPhiladelphiaPennsylvania
- Applied Physiology and KinesiologyCollege of Health and Human Performance, University of FloridaGainesvilleFlorida
| | - Jennifer Pham
- Department of Physiology, Perleman School of Medicine, University of PennsylvaniaPhiladelphiaPennsylvania
| | - Becky K. Brisson
- Anatomy and Cell Biology, School of Dental MedicineUniversity of PennsylvaniaPhiladelphiaPennsylvania
| | - SooHyun Park
- Anatomy and Cell Biology, School of Dental MedicineUniversity of PennsylvaniaPhiladelphiaPennsylvania
| | - Lucas R. Smith
- Anatomy and Cell Biology, School of Dental MedicineUniversity of PennsylvaniaPhiladelphiaPennsylvania
| | - Min Liu
- Department of Physiology, Perleman School of Medicine, University of PennsylvaniaPhiladelphiaPennsylvania
| | - Zuozhen Tian
- Anatomy and Cell Biology, School of Dental MedicineUniversity of PennsylvaniaPhiladelphiaPennsylvania
| | - David W. Hammers
- Department of Pharmacology and Therapeutics, College of Medicine, University of FloridaGainesvilleFlorida
| | - Georgios Vassilakos
- Applied Physiology and KinesiologyCollege of Health and Human Performance, University of FloridaGainesvilleFlorida
| | - H. Lee Sweeney
- Department of Physiology, Perleman School of Medicine, University of PennsylvaniaPhiladelphiaPennsylvania
- Department of Pharmacology and Therapeutics, College of Medicine, University of FloridaGainesvilleFlorida
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17
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Hunt LC, Stover J, Haugen B, Shaw TI, Li Y, Pagala VR, Finkelstein D, Barton ER, Fan Y, Labelle M, Peng J, Demontis F. A Key Role for the Ubiquitin Ligase UBR4 in Myofiber Hypertrophy in Drosophila and Mice. Cell Rep 2019; 28:1268-1281.e6. [PMID: 31365869 PMCID: PMC6697171 DOI: 10.1016/j.celrep.2019.06.094] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2018] [Revised: 05/07/2019] [Accepted: 06/26/2019] [Indexed: 12/31/2022] Open
Abstract
Skeletal muscle cell (myofiber) atrophy is a detrimental component of aging and cancer that primarily results from muscle protein degradation via the proteasome and ubiquitin ligases. Transcriptional upregulation of some ubiquitin ligases contributes to myofiber atrophy, but little is known about the role that most other ubiquitin ligases play in this process. To address this question, we have used RNAi screening in Drosophila to identify the function of > 320 evolutionarily conserved ubiquitin ligases in myofiber size regulation in vivo. We find that whereas RNAi for some ubiquitin ligases induces myofiber atrophy, loss of others (including the N-end rule ubiquitin ligase UBR4) promotes hypertrophy. In Drosophila and mouse myofibers, loss of UBR4 induces hypertrophy via decreased ubiquitination and degradation of a core set of target proteins, including the HAT1/RBBP4/RBBP7 histone-binding complex. Together, this study defines the repertoire of ubiquitin ligases that regulate myofiber size and the role of UBR4 in myofiber hypertrophy.
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Affiliation(s)
- Liam C Hunt
- Division of Developmental Biology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA; Department of Developmental Neurobiology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA
| | - Jared Stover
- Division of Developmental Biology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA; Department of Developmental Neurobiology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA
| | - Benard Haugen
- Division of Developmental Biology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA; Department of Developmental Neurobiology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA
| | - Timothy I Shaw
- Department of Structural Biology, Center for Proteomics and Metabolomics, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA
| | - Yuxin Li
- Department of Structural Biology, Center for Proteomics and Metabolomics, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA
| | - Vishwajeeth R Pagala
- Department of Structural Biology, Center for Proteomics and Metabolomics, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA
| | - David Finkelstein
- Department of Computational Biology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA
| | - Elisabeth R Barton
- College of Health & Human Performance Applied Physiology & Kinesiology, University of Florida, 124 Florida Gym, 1864 Stadium Road, Gainesville, FL 32611, USA
| | - Yiping Fan
- Department of Computational Biology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA
| | - Myriam Labelle
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA; Solid Tumor Program, Comprehensive Cancer Center, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA
| | - Junmin Peng
- Department of Structural Biology, Center for Proteomics and Metabolomics, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA; Department of Developmental Neurobiology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA
| | - Fabio Demontis
- Division of Developmental Biology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA; Department of Developmental Neurobiology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA.
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18
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Kok HJ, Oster JC, Conover CF, Fletcher DB, Barton ER, Yarrow JF. Neuromuscular Impairment Following Chronic Moderate-Severe Contusion in Spinal Cord Injured Rats. Med Sci Sports Exerc 2019. [DOI: 10.1249/01.mss.0000561424.39024.39] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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19
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Spradlin RA, Vassilakos G, Matheny M, Jones NC, Goldman J, Lei H, Barton ER. Loss of Muscle IGF‐I Production Delays Functional Recovery of Skeletal Muscle Following Disuse. FASEB J 2019. [DOI: 10.1096/fasebj.2019.33.1_supplement.700.23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | | | - Michael Matheny
- Pharmacology and TherapeuticsUniversity of FloridaGainesvillFL
| | - Nathan C Jones
- Applied Physiology and KinesiologyUniversity of FloridaGainesvillFL
| | - Jessica Goldman
- Applied Physiology and KinesiologyUniversity of FloridaGainesvillFL
| | - Hanqin Lei
- Applied Physiology and KinesiologyUniversity of FloridaGainesvillFL
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20
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Yang Y, Vassilakos G, Hammers DW, Yang Z, Barton ER, Sweeney HL. Smooth muscle atrophy and colon pathology in SMN deficient mice. Am J Transl Res 2019; 11:1789-1799. [PMID: 30972202 PMCID: PMC6456546] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2018] [Accepted: 12/23/2018] [Indexed: 06/09/2023]
Abstract
Spinal muscular atrophy (SMA) is an autosomal recessive genetic disorder characterized by loss of motor neurons in the ventral horn of the spinal cord. Clinical features such as progressively lethal respiratory weakness and associated muscle wasting have been extensively studied but less attention has been given to gastrointestinal (GI) dysfunction, which is common symptomatology in SMA patients with 43% constipation, 15% abdominal pain, and 14% meteorism. In the current study, the PrP92-SMN mouse model of SMA was utilized, to complement previous studies in which cells of the Enteric Nervous system (ENS) were susceptible to Smn (survival motor neuron) deficiency and could possibly be the basis of the observed GI symptoms. Necropsy of our mouse model showed impairment in feces excretion and smaller bladder mass, compared to Wild-Type (WT) animals. Along with the reduction in bladder mass, we also observed a decrease in the size of smooth muscles, due to reduction in Cross-Sectional Area (CSA). Interstitial cells of Cajal (ICC) provide important regulatory functions in the GI tract. To investigate if ICC are implicated in Smn deficient-induced colonic dysmotility, we assessed ICC distribution and abundance, by c-Kit, a well-established marker. SMA mice exhibited fewer c-Kit positive cells with altered localization, compared to WT. In conclusion, the observed histopathological abnormalities of our mouse model, can be secondary to SMN deficiency and could possibly underlie the GI symptoms observed in SMA patients. Future therapeutic approaches for SMA, must address not only CNS symptoms, but also non-motor-neuron-related symptoms. The PrP92-SMN mouse model could be a useful model for assessing therapeutic rescue of GI dysfunction in SMA.
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Affiliation(s)
- Yun Yang
- Department of Gastrointestinal Surgery, West China/Chengdu Shangjin Nanfu Hospital, Sichuan UniversityChengdu, Sichuan Province, China
- Department of Pharmacology and Therapeutics, University of Florida College of Medicine, Gainesville, FL Myology Institute, University of Florida College of MedicineGainesville, FL
| | - George Vassilakos
- Department of Applied Physiology and Kinesiology, University of Florida College of Health and Human PerformanceGainesville, FL
| | - David W Hammers
- Department of Pharmacology and Therapeutics, University of Florida College of Medicine, Gainesville, FL Myology Institute, University of Florida College of MedicineGainesville, FL
| | - Zhaohui Yang
- Department of Physiology, University of Pennsylvania Perelman School of MedicinePhiladelphia, PA
- Department of Pharmacology and Therapeutics, University of Florida College of Medicine, Gainesville, FL Myology Institute, University of Florida College of MedicineGainesville, FL
| | - Elisabeth R Barton
- Department of Physiology, University of Pennsylvania Perelman School of MedicinePhiladelphia, PA
- Department of Applied Physiology and Kinesiology, University of Florida College of Health and Human PerformanceGainesville, FL
| | - Hugh Lee Sweeney
- Department of Physiology, University of Pennsylvania Perelman School of MedicinePhiladelphia, PA
- Department of Pharmacology and Therapeutics, University of Florida College of Medicine, Gainesville, FL Myology Institute, University of Florida College of MedicineGainesville, FL
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21
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Abstract
The insulin-like growth factor (IGF) pathway is essential for promoting growth and survival of virtually all tissues. It bears high homology to its related protein insulin, and as such, there is an interplay between these molecules with regard to their anabolic and metabolic functions. Skeletal muscle produces a significant proportion of IGF-1, and is highly responsive to its actions, including increased muscle mass and improved regenerative capacity. In this overview, the regulation of IGF-1 production, stability, and activity in skeletal muscle will be described. Second, the physiological significance of the forms of IGF-1 produced will be discussed. Last, the interaction of IGF-1 with other pathways will be addressed. © 2019 American Physiological Society. Compr Physiol 9:413-438, 2019.
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Affiliation(s)
- Georgios Vassilakos
- Department of Applied Physiology and Kinesiology, College of Health and Human Performance, University of Florida, Gainesville, Florida, USA
| | - Elisabeth R Barton
- Department of Applied Physiology and Kinesiology, College of Health and Human Performance, University of Florida, Gainesville, Florida, USA
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22
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Smith TC, Saul RG, Barton ER, Luna EJ. Generation and characterization of monoclonal antibodies that recognize human and murine supervillin protein isoforms. PLoS One 2018; 13:e0205910. [PMID: 30332471 PMCID: PMC6192639 DOI: 10.1371/journal.pone.0205910] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2018] [Accepted: 10/02/2018] [Indexed: 01/06/2023] Open
Abstract
Supervillin isoforms have been implicated in cell proliferation, actin filament-based motile processes, vesicle trafficking, and signal transduction. However, an understanding of the roles of these proteins in cancer metastasis and physiological processes has been limited by the difficulty of obtaining specific antibodies against these highly conserved membrane-associated proteins. To facilitate research into the biological functions of supervillin, monoclonal antibodies were generated against the bacterially expressed human supervillin N-terminus. Two chimeric monoclonal antibodies with rabbit Fc domains (clones 1E2/CPTC-SVIL-1; 4A8/CPTC-SVIL-2) and two mouse monoclonal antibodies (clones 5A8/CPTC-SVIL-3; 5G3/CPTC-SVIL-4) were characterized with respect to their binding sites, affinities, and for efficacy in immunoblotting, immunoprecipitation, immunofluorescence microscopy and immunohistochemical staining. Two antibodies (1E2, 5G3) recognize a sequence found only in primate supervillins, whereas the other two antibodies (4A8, 5A8) are specific for a more broadly conserved conformational epitope(s). All antibodies function in immunoblotting, immunoprecipitation and in immunofluorescence microscopy under the fixation conditions identified here. We also show that the 5A8 antibody works on immunohistological sections. These antibodies should provide useful tools for the study of mammalian supervillins.
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Affiliation(s)
- Tara C. Smith
- Department of Radiology, Division of Cell Biology & Imaging, University of Massachusetts Medical School, Worcester, MA, United States of America
| | - Richard G. Saul
- Antibody Characterization Laboratory, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research ATRF, Frederick, MD, United States of America
| | - Elisabeth R. Barton
- Applied Physiology & Kinesiology, College of Health & Human Performance, University of Florida, Gainesville, FL, United States of America
| | - Elizabeth J. Luna
- Department of Radiology, Division of Cell Biology & Imaging, University of Massachusetts Medical School, Worcester, MA, United States of America
- * E-mail:
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23
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Chrzanowski SM, Vohra RS, Lee-McMullen BA, Batra A, Spradlin RA, Morales J, Forbes S, Vandenborne K, Barton ER, Walter GA. Contrast-Enhanced Near-Infrared Optical Imaging Detects Exacerbation and Amelioration of Murine Muscular Dystrophy. Mol Imaging 2018; 16:1536012117732439. [PMID: 29271299 PMCID: PMC5985549 DOI: 10.1177/1536012117732439] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Assessment of muscle pathology is a key outcome measure to measure the success of
clinical trials studying muscular dystrophies; however, few robust minimally invasive
measures exist. Indocyanine green (ICG)-enhanced near-infrared (NIR) optical imaging
offers an objective, minimally invasive, and longitudinal modality that can quantify
pathology within muscle by imaging uptake of ICG into the damaged muscles. Dystrophic mice
lacking dystrophin (mdx) or gamma-sarcoglycan (Sgcg−/−) were compared to
control mice by NIR optical imaging and magnetic resonance imaging (MRI). We determined
that optical imaging could be used to differentiate control and dystrophic mice, visualize
eccentric muscle induced by downhill treadmill running, and restore the membrane integrity
in Sgcg−/− mice following adeno-associated virus (AAV) delivery of recombinant
human SGCG (desAAV8hSGCG). We conclude that NIR optical imaging is comparable to MRI and
can be used to detect muscle damage in dystrophic muscle as compared to unaffected
controls, monitor worsening of muscle pathology in muscular dystrophy, and assess
regression of pathology following therapeutic intervention in muscular dystrophies.
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Affiliation(s)
- Stephen M Chrzanowski
- 1 Department of Physiology and Functional Genomics, University of Florida, Gainesville, FL, USA
| | - Ravneet S Vohra
- 1 Department of Physiology and Functional Genomics, University of Florida, Gainesville, FL, USA
| | | | - Abhinandan Batra
- 3 Department of Physical Therapy, University of Florida, Gainesville, FL, USA
| | - Ray A Spradlin
- 4 Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL, USA
| | - Jazmine Morales
- 4 Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL, USA
| | - Sean Forbes
- 3 Department of Physical Therapy, University of Florida, Gainesville, FL, USA
| | - Krista Vandenborne
- 3 Department of Physical Therapy, University of Florida, Gainesville, FL, USA
| | - Elisabeth R Barton
- 4 Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL, USA
| | - Glenn A Walter
- 1 Department of Physiology and Functional Genomics, University of Florida, Gainesville, FL, USA
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24
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Vassilakos G, Lei H, Yang Y, Puglise J, Matheny M, Durzynska J, Ozery M, Bennett K, Spradlin R, Bonanno H, Park S, Ahima RS, Barton ER. Deletion of muscle IGF-I transiently impairs growth and progressively disrupts glucose homeostasis in male mice. FASEB J 2018; 33:181-194. [PMID: 29932867 DOI: 10.1096/fj.201800459r] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Insulin-like growth factors (IGFs) are essential for local skeletal muscle growth and organismal physiology, but these actions are entwined with glucose homeostasis through convergence with insulin signaling. The objective of this work was to determine whether the effects of IGF-I on growth and metabolism could be separated. We generated muscle-specific IGF-I-deficient (MID) mice that afford inducible deletion of Igf1 at any age. After Igf1 deletion at birth or in young adult mice, evaluations of muscle physiology and glucose homeostasis were performed up to 16 wk of age. MID mice generated at birth had lower muscle and circulating IGF-I, decreased muscle and body mass, and impaired muscle force production. Eight-wk-old male MID had heightened insulin levels with trends of elevated fasting glucose. This phenotype progressed to impaired glucose handling and increased fat deposition without significant muscle mass loss at 16 wk of age. The same phenotype emerged in 16-wk-old MID mice induced at 12 wk of age, compounded with heightened muscle fatigability and exercise intolerance. We assert that muscle IGF-I independently modulates anabolism and metabolism in an age-dependent manner, thus positioning muscle IGF-I maintenance to be critical for both muscle growth and metabolic homeostasis.-Vassilakos, G., Lei, H., Yang, Y., Puglise, J., Matheny, M., Durzynska, J., Ozery, M., Bennett, K., Spradlin, R., Bonanno, H., Park, S., Ahima, R. S., Barton, E. R. Deletion of muscle IGF-I transiently impairs growth and progressively disrupts glucose homeostasis in male mice.
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Affiliation(s)
- Georgios Vassilakos
- Applied Physiology and Kinesiology, College of Health and Human Performance, University of Florida, Gainesville, Florida, USA
| | - Hanqin Lei
- Applied Physiology and Kinesiology, College of Health and Human Performance, University of Florida, Gainesville, Florida, USA
| | - Yun Yang
- Pharmacology and Therapeutics, College of Medicine, University of Florida, Gainesville, Florida, USA.,Gastrointestinal Surgery, West China School of Medicine, Sichuan University-West China Hospital, Chengdu, China
| | - Jason Puglise
- Applied Physiology and Kinesiology, College of Health and Human Performance, University of Florida, Gainesville, Florida, USA
| | - Michael Matheny
- Pharmacology and Therapeutics, College of Medicine, University of Florida, Gainesville, Florida, USA
| | - Julia Durzynska
- Applied Physiology and Kinesiology, College of Health and Human Performance, University of Florida, Gainesville, Florida, USA.,Molecular Virology, Institute of Experimental Biology, A. Mickiewicz University, Poznań, Poland
| | - Matan Ozery
- Applied Physiology and Kinesiology, College of Health and Human Performance, University of Florida, Gainesville, Florida, USA
| | - Katherine Bennett
- Applied Physiology and Kinesiology, College of Health and Human Performance, University of Florida, Gainesville, Florida, USA
| | - Ray Spradlin
- Applied Physiology and Kinesiology, College of Health and Human Performance, University of Florida, Gainesville, Florida, USA
| | - Heather Bonanno
- Animal Care Services, Cancer and Genetics Research Complex, University of Florida, Gainesville, Florida, USA
| | - Soohyun Park
- Institute of Molecular Medicine, University of Texas Health Science Center at Houston, Houston, Texas, USA
| | - Rexford S Ahima
- Division of Endocrinology, Diabetes and Metabolism, Johns Hopkins University, Baltimore, Maryland, USA
| | - Elisabeth R Barton
- Applied Physiology and Kinesiology, College of Health and Human Performance, University of Florida, Gainesville, Florida, USA.,Pharmacology and Therapeutics, College of Medicine, University of Florida, Gainesville, Florida, USA
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25
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Abstract
The production of force and power are inherent properties of skeletal muscle, and regulated by contractile proteins within muscle fibers. However, skeletal muscle integrity and function also require strong connections between muscle fibers and their extracellular matrix (ECM). A well-organized and pliant ECM is integral to muscle function and the ability for many different cell populations to efficiently migrate through ECM is critical during growth and regeneration. For many neuromuscular diseases, genetic mutations cause disruption of these cytoskeletal-ECM connections, resulting in muscle fragility and chronic injury. Ultimately, these changes shift the balance from myogenic pathways toward fibrogenic pathways, culminating in the loss of muscle fibers and their replacement with fatty-fibrotic matrix. Hence a common pathological hallmark of muscular dystrophy is prominent fibrosis. This review will cover the salient features of muscular dystrophy pathogenesis, highlight the signals and cells that are important for myogenic and fibrogenic actions, and discuss how fibrosis alters the ECM of skeletal muscle, and the consequences of fibrosis in developing therapies.
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Affiliation(s)
- Lucas R Smith
- Department of Chemical and Biomolecular Engineering, University of Pennsylvania, Philadelphia, PA, United States
| | - Elisabeth R Barton
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL, United States.
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26
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Pickard A, Durzynska J, McCance DJ, Barton ER. The IGF axis in HPV associated cancers. Mutat Res Rev Mutat Res 2017; 772:67-77. [PMID: 28528691 DOI: 10.1016/j.mrrev.2017.01.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2016] [Revised: 01/30/2017] [Accepted: 01/30/2017] [Indexed: 02/07/2023]
Abstract
Human papillomaviruses (HPV) infect and replicate in stratified epithelium at cutaneous and mucosal surfaces. The proliferation and maintenance of keratinocytes, the cells which make up this epithelium, are controlled by a number of growth factor receptors such as the keratinocyte growth factor receptor (KGFR, also called fibroblast growth factor receptor 2b (FGFR2b)), the epithelial growth factor receptor (EGFR) and the insulin-like growth factor receptors 1 and 2 (IGF1R and IGF2R). In this review, we will delineate the mutation, gene transcription, translation and processing of the IGF axis within HPV associated cancers. The IGFs are key for developmental and postnatal growth of almost all tissues; we explore whether this crucial axis has been hijacked by HPV.
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MESH Headings
- Cell Proliferation
- ErbB Receptors/genetics
- ErbB Receptors/metabolism
- Gene Expression Regulation, Neoplastic
- Humans
- Keratinocytes/cytology
- Keratinocytes/virology
- Neoplasms/genetics
- Neoplasms/virology
- Papillomaviridae/pathogenicity
- Receptor, Fibroblast Growth Factor, Type 2/genetics
- Receptor, Fibroblast Growth Factor, Type 2/metabolism
- Receptor, IGF Type 1
- Receptor, IGF Type 2/genetics
- Receptor, IGF Type 2/metabolism
- Receptors, Somatomedin/genetics
- Receptors, Somatomedin/metabolism
- Somatomedins/genetics
- Somatomedins/metabolism
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Affiliation(s)
- Adam Pickard
- Centre for Cancer Research and Cell Biology, Queen's University Belfast, Belfast, BT9 7AE, UK; Wellcome Centre for Cell Matrix Research, University of Manchester, M13 9PL, UK.
| | - Julia Durzynska
- Department of Molecular Virology, Institute of Experimental Biology, A. Mickiewicz University, ul. Umultowska 89, 61-614, Poznań, Poland; Department of Applied Physiology and Kinesiology, College of Health and Human Performance, University of Florida, Gainesville, FL, USA
| | - Dennis J McCance
- Department of Pathology, University of New Mexico, Albuquerque, NM, USA
| | - Elisabeth R Barton
- Department of Applied Physiology and Kinesiology, College of Health and Human Performance, University of Florida, Gainesville, FL, USA
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27
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Capote J, Kramerova I, Martinez L, Vetrone S, Barton ER, Sweeney HL, Miceli MC, Spencer MJ. Osteopontin ablation ameliorates muscular dystrophy by shifting macrophages to a pro-regenerative phenotype. J Exp Med 2016. [DOI: 10.1084/jem.2135oia35] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
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28
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Capote J, Kramerova I, Martinez L, Vetrone S, Barton ER, Sweeney HL, Miceli MC, Spencer MJ. Osteopontin ablation ameliorates muscular dystrophy by shifting macrophages to a pro-regenerative phenotype. J Cell Biol 2016; 213:275-88. [PMID: 27091452 PMCID: PMC5084275 DOI: 10.1083/jcb.201510086] [Citation(s) in RCA: 89] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2015] [Accepted: 03/15/2016] [Indexed: 11/22/2022] Open
Abstract
In the degenerative disease Duchenne muscular dystrophy, inflammatory cells enter muscles in response to repetitive muscle damage. Immune factors are required for muscle regeneration, but chronic inflammation creates a profibrotic milieu that exacerbates disease progression. Osteopontin (OPN) is an immunomodulator highly expressed in dystrophic muscles. Ablation of OPN correlates with reduced fibrosis and improved muscle strength as well as reduced natural killer T (NKT) cell counts. Here, we demonstrate that the improved dystrophic phenotype observed with OPN ablation does not result from reductions in NKT cells. OPN ablation skews macrophage polarization toward a pro-regenerative phenotype by reducing M1 and M2a and increasing M2c subsets. These changes are associated with increased expression of pro-regenerative factors insulin-like growth factor 1, leukemia inhibitory factor, and urokinase-type plasminogen activator. Furthermore, altered macrophage polarization correlated with increases in muscle weight and muscle fiber diameter, resulting in long-term improvements in muscle strength and function in mdx mice. These findings suggest that OPN ablation promotes muscle repair via macrophage secretion of pro-myogenic growth factors.
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Affiliation(s)
- Joana Capote
- Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095 Molecular, Cellular, and Integrative Physiology Interdepartmental PhD Program, University of California, Los Angeles, Los Angeles, CA 90095
| | - Irina Kramerova
- Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095
| | - Leonel Martinez
- Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095
| | - Sylvia Vetrone
- Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095
| | - Elisabeth R Barton
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL 32611 Wellstone Muscular Dystrophy Center, University of Florida, Gainesville, FL 32610
| | - H Lee Sweeney
- Department of Pharmacology and Therapeutics, University of Florida, Gainesville, FL 32610 Wellstone Muscular Dystrophy Center, University of Florida, Gainesville, FL 32610
| | - M Carrie Miceli
- Department of Microbiology, Immunology, and Molecular Genetics, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095 Center for Duchenne Muscular Dystrophy at UCLA, Los Angeles, CA 90095 Wellstone Muscular Dystrophy Center, University of Florida, Gainesville, FL 32610
| | - Melissa J Spencer
- Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095 Center for Duchenne Muscular Dystrophy at UCLA, Los Angeles, CA 90095 Wellstone Muscular Dystrophy Center, University of Florida, Gainesville, FL 32610
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29
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Abstract
Introduction Collagen cross‐linking is a key parameter in extracellular matrix (ECM) maturation, turnover, and stiffness. We examined aspects of collagen cross‐linking in dystrophin‐deficient murine, canine, and human skeletal muscle. Methods DMD patient biopsies and samples from mdx mice and golden retriever muscular dystrophy dog samples (with appropriate controls) were analyzed. Collagen cross‐linking was evaluated using solubility and hydroxyproline assays. Expression of the cross‐linking enzyme lysyl oxidase (LOX) was determined by real‐time polymerase chain reaction, immunoblotting, and immunofluorescence. Results LOX protein levels are increased in dystrophic muscle from all species evaluated. Dystrophic mice and dogs had significantly higher cross‐linked collagen than controls, especially in the diaphragm. Distribution of intramuscular LOX was heterogeneous in all samples, but it increased in frequency and intensity in dystrophic muscle. Conclusion These findings implicate elevated collagen cross‐linking as an important component of the disrupted ECM in dystrophic muscles, and heightened cross‐linking is evident in mouse, dog, and man. Muscle Nerve54: 71–78, 2016
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Affiliation(s)
- Lucas R Smith
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA.,Pennsylvania Muscle Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - David W Hammers
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA.,Pennsylvania Muscle Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA.,Department of Pharmacology & Therapeutics, College of Medicine, University of Florida, Gainesville, Florida, USA.,Myology Institute, University of Florida, Gainesville, Florida, USA
| | - H Lee Sweeney
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA.,Pennsylvania Muscle Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA.,Department of Pharmacology & Therapeutics, College of Medicine, University of Florida, Gainesville, Florida, USA.,Myology Institute, University of Florida, Gainesville, Florida, USA
| | - Elisabeth R Barton
- Pennsylvania Muscle Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA.,Myology Institute, University of Florida, Gainesville, Florida, USA.,Department of Applied Physiology and Kinesiology, College of Health and Human Performance, University of Florida, 1864 Stadium Road, 124 Florida Gym, Gainesville, Florida, 32611, USA
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30
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Abstract
Skeletal muscle and bone rely on a number of growth factors to undergo development, modulate growth, and maintain physiological strength. A major player in these actions is insulin-like growth factor I (IGF-I). However, because this growth factor can directly enhance muscle mass and bone density, it alters the state of the musculoskeletal system indirectly through mechanical crosstalk between these two organ systems. Thus, there are clearly synergistic actions of IGF-I that extend beyond the direct activity through its receptor. This review will cover the production and signaling of IGF-I as it pertains to muscle and bone, the chemical and mechanical influences that arise from IGF-I activity, and the potential for therapeutic strategies based on IGF-I. This article is part of a Special Issue entitled "Muscle Bone Interactions".
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Affiliation(s)
- Daniel D Bikle
- VA Medical Center and University of California San Francisco, San Francisco, CA, USA
| | - Candice Tahimic
- VA Medical Center and University of California San Francisco, San Francisco, CA, USA
| | - Wenhan Chang
- VA Medical Center and University of California San Francisco, San Francisco, CA, USA
| | - Yongmei Wang
- VA Medical Center and University of California San Francisco, San Francisco, CA, USA
| | - Anastassios Philippou
- National and Kapodistrian University of Athens, Department of Physiology, Medical School, Goudi-Athens, Greece
| | - Elisabeth R Barton
- Department of Applied Physiology and Kinesiology, College of Health and Human Performance, University of Florida, Gainesville, FL, USA.
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31
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Di Rocco A, Uchibe K, Larmour C, Berger R, Liu M, Barton ER, Iwamoto M. Selective Retinoic Acid Receptor γ Agonists Promote Repair of Injured Skeletal Muscle in Mouse. Am J Pathol 2015; 185:2495-504. [PMID: 26205250 PMCID: PMC4597269 DOI: 10.1016/j.ajpath.2015.05.007] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2014] [Revised: 04/16/2015] [Accepted: 05/19/2015] [Indexed: 10/23/2022]
Abstract
Retinoic acid signaling regulates several biological events, including myogenesis. We previously found that retinoic acid receptor γ (RARγ) agonist blocks heterotopic ossification, a pathological bone formation that mostly occurs in the skeletal muscle. Interestingly, RARγ agonist also weakened deterioration of muscle architecture adjacent to the heterotopic ossification lesion, suggesting that RARγ agonist may oppose skeletal muscle damage. To test this hypothesis, we generated a critical defect in the tibialis anterior muscle of 7-week-old mice with a cautery, treated them with RARγ agonist or vehicle corn oil, and examined the effects of RARγ agonist on muscle repair. The muscle defects were partially repaired with newly regenerating muscle cells, but also filled with adipose and fibrous scar tissue in both RARγ-treated and control groups. The fibrous or adipose area was smaller in RARγ agonist-treated mice than in the control. In addition, muscle repair was remarkably delayed in RARγ-null mice in both critical defect and cardiotoxin injury models. Furthermore, we found a rapid increase in retinoid signaling in lacerated muscle, as monitored by retinoid signaling reporter mice. Together, our results indicate that endogenous RARγ signaling is involved in muscle repair and that selective RARγ agonists may be beneficial to promote repair in various types of muscle injuries.
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Affiliation(s)
- Agnese Di Rocco
- Translational Research Program in Pediatric Orthopaedics, The Children's Hospital of Philadelphia Research Institute, Philadelphia
| | - Kenta Uchibe
- Translational Research Program in Pediatric Orthopaedics, The Children's Hospital of Philadelphia Research Institute, Philadelphia
| | - Colleen Larmour
- Translational Research Program in Pediatric Orthopaedics, The Children's Hospital of Philadelphia Research Institute, Philadelphia
| | - Rebecca Berger
- Translational Research Program in Pediatric Orthopaedics, The Children's Hospital of Philadelphia Research Institute, Philadelphia
| | - Min Liu
- Department of Physiology, School of Dental Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Elisabeth R Barton
- Department of Anatomy and Cell Biology, School of Dental Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Masahiro Iwamoto
- Translational Research Program in Pediatric Orthopaedics, The Children's Hospital of Philadelphia Research Institute, Philadelphia.
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32
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Lee YS, Lehar A, Sebald S, Liu M, Swaggart KA, Talbot CC, Pytel P, Barton ER, McNally EM, Lee SJ. Muscle hypertrophy induced by myostatin inhibition accelerates degeneration in dysferlinopathy. Hum Mol Genet 2015. [PMID: 26206886 PMCID: PMC4581601 DOI: 10.1093/hmg/ddv288] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Myostatin is a secreted signaling molecule that normally acts to limit muscle growth. As a result, there is extensive effort directed at developing drugs capable of targeting myostatin to treat patients with muscle loss. One potential concern with this therapeutic approach in patients with muscle degenerative diseases like muscular dystrophy is that inducing hypertrophy may increase stress on dystrophic fibers, thereby accelerating disease progression. To investigate this possibility, we examined the effect of blocking the myostatin pathway in dysferlin-deficient (Dysf−/−) mice, in which membrane repair is compromised, either by transgenic expression of follistatin in skeletal muscle or by systemic administration of the soluble form of the activin type IIB receptor (ACVR2B/Fc). Here, we show that myostatin inhibition by follistatin transgene expression in Dysf−/− mice results in early improvement in histopathology but ultimately exacerbates muscle degeneration; this effect was not observed in dystrophin-deficient (mdx) mice, suggesting that accelerated degeneration induced by follistatin transgene expression is specific to mice lacking dysferlin. Dysf−/− mice injected with ACVR2B/Fc showed significant increases in muscle mass and amelioration of fibrotic changes normally seen in 8-month-old Dysf−/− mice. Despite these potentially beneficial effects, ACVR2B/Fc treatment caused increases in serum CK levels in some Dysf−/− mice, indicating possible muscle damage induced by hypertrophy. These findings suggest that depending on the disease context, inducing muscle hypertrophy by myostatin blockade may have detrimental effects, which need to be weighed against the potential gains in muscle growth and decreased fibrosis.
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Affiliation(s)
- Yun-Sil Lee
- Department of Molecular Biology and Genetics and
| | - Adam Lehar
- Department of Molecular Biology and Genetics and
| | | | - Min Liu
- Department of Physiology, Perelman School of Medicine and
| | | | - C Conover Talbot
- Institute for Basic Biomedical Sciences, Johns Hopkins University School of Medicine, 725 North Wolfe Street, PCTB 803, Baltimore, MD 21205, USA
| | - Peter Pytel
- Department of Pathology, The University of Chicago, Chicago, IL 60637, USA
| | - Elisabeth R Barton
- Department of Anatomy and Cell Biology, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | | | - Se-Jin Lee
- Department of Molecular Biology and Genetics and
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33
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Ceco E, Bogdanovich S, Gardner B, Miller T, DeJesus A, Earley JU, Hadhazy M, Smith LR, Barton ER, Molkentin JD, McNally EM. Targeting latent TGFβ release in muscular dystrophy. Sci Transl Med 2015; 6:259ra144. [PMID: 25338755 DOI: 10.1126/scitranslmed.3010018] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Latent transforming growth factor-β (TGFβ) binding proteins (LTBPs) bind to inactive TGFβ in the extracellular matrix. In mice, muscular dystrophy symptoms are intensified by a genetic polymorphism that changes the hinge region of LTBP, leading to increased proteolytic susceptibility and TGFβ release. We have found that the hinge region of human LTBP4 was also readily proteolysed and that proteolysis could be blocked by an antibody to the hinge region. Transgenic mice were generated to carry a bacterial artificial chromosome encoding the human LTBP4 gene. These transgenic mice displayed larger myofibers, increased damage after muscle injury, and enhanced TGFβ signaling. In the mdx mouse model of Duchenne muscular dystrophy, the human LTBP4 transgene exacerbated muscular dystrophy symptoms and resulted in weaker muscles with an increased inflammatory infiltrate and greater LTBP4 cleavage in vivo. Blocking LTBP4 cleavage may be a therapeutic strategy to reduce TGFβ release and activity and decrease inflammation and muscle damage in muscular dystrophy.
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Affiliation(s)
- Ermelinda Ceco
- Committee on Cell Physiology, The University of Chicago, Chicago, IL 60637, USA
| | - Sasha Bogdanovich
- Department of Medicine, The University of Chicago, Chicago, IL 60637, USA
| | - Brandon Gardner
- Molecular Pathogenesis and Molecular Medicine, The University of Chicago, Chicago, IL 60637, USA
| | - Tamari Miller
- Department of Medicine, The University of Chicago, Chicago, IL 60637, USA
| | - Adam DeJesus
- Department of Medicine, The University of Chicago, Chicago, IL 60637, USA
| | - Judy U Earley
- Department of Medicine, The University of Chicago, Chicago, IL 60637, USA
| | - Michele Hadhazy
- Department of Medicine, The University of Chicago, Chicago, IL 60637, USA
| | - Lucas R Smith
- Department of Anatomy and Cell Biology, School of Dental Medicine, Pennsylvania Muscle Institute, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Elisabeth R Barton
- Department of Anatomy and Cell Biology, School of Dental Medicine, Pennsylvania Muscle Institute, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Jeffery D Molkentin
- Cincinnati Children's Hospital Medical Center, Howard Hughes Medical Institute, Cincinnati, OH 45229, USA
| | - Elizabeth M McNally
- Department of Medicine, The University of Chicago, Chicago, IL 60637, USA. Department of Human Genetics, The University of Chicago, Chicago, IL 60637, USA.
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Philippou A, Minozzo FC, Spinazzola JM, Smith LR, Lei H, Rassier DE, Barton ER. Masticatory muscles of mouse do not undergo atrophy in space. FASEB J 2015; 29:2769-79. [PMID: 25795455 DOI: 10.1096/fj.14-267336] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2014] [Accepted: 03/02/2015] [Indexed: 02/06/2023]
Abstract
Muscle loading is important for maintaining muscle mass; when load is removed, atrophy is inevitable. However, in clinical situations such as critical care myopathy, masticatory muscles do not lose mass. Thus, their properties may be harnessed to preserve mass. We compared masticatory and appendicular muscles responses to microgravity, using mice aboard the space shuttle Space Transportation System-135. Age- and sex-matched controls remained on the ground. After 13 days of space flight, 1 masseter (MA) and tibialis anterior (TA) were frozen rapidly for biochemical and functional measurements, and the contralateral MA was processed for morphologic measurements. Flight TA muscles exhibited 20 ± 3% decreased muscle mass, 2-fold decreased phosphorylated (P)-Akt, and 4- to 12-fold increased atrogene expression. In contrast, MAs had no significant change in mass but a 3-fold increase in P-focal adhesion kinase, 1.5-fold increase in P-Akt, and 50-90% lower atrogene expression compared with limb muscles, which were unaltered in microgravity. Myofibril force measurements revealed that microgravity caused a 3-fold decrease in specific force and maximal shortening velocity in TA muscles. It is surprising that myofibril-specific force from both control and flight MAs were similar to flight TA muscles, yet power was compromised by 40% following flight. Continued loading in microgravity prevents atrophy, but masticatory muscles have a different set point that mimics disuse atrophy in the appendicular muscle.
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Affiliation(s)
- Anastassios Philippou
- *Department of Physiology, Medical School, National and Kapodistrian University of Athens, Goudi-Athens, Greece; Department of Anatomy and Cell Biology, School of Dental Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA; Department of Kinesiology, McGill University, Montreal, Quebec, Canada; Pennsylvania Muscle Institute, University of Pennsylvania, Philadelphia, Pennsylvania, USA; and Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, Florida, USA
| | - Fabio C Minozzo
- *Department of Physiology, Medical School, National and Kapodistrian University of Athens, Goudi-Athens, Greece; Department of Anatomy and Cell Biology, School of Dental Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA; Department of Kinesiology, McGill University, Montreal, Quebec, Canada; Pennsylvania Muscle Institute, University of Pennsylvania, Philadelphia, Pennsylvania, USA; and Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, Florida, USA
| | - Janelle M Spinazzola
- *Department of Physiology, Medical School, National and Kapodistrian University of Athens, Goudi-Athens, Greece; Department of Anatomy and Cell Biology, School of Dental Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA; Department of Kinesiology, McGill University, Montreal, Quebec, Canada; Pennsylvania Muscle Institute, University of Pennsylvania, Philadelphia, Pennsylvania, USA; and Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, Florida, USA
| | - Lucas R Smith
- *Department of Physiology, Medical School, National and Kapodistrian University of Athens, Goudi-Athens, Greece; Department of Anatomy and Cell Biology, School of Dental Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA; Department of Kinesiology, McGill University, Montreal, Quebec, Canada; Pennsylvania Muscle Institute, University of Pennsylvania, Philadelphia, Pennsylvania, USA; and Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, Florida, USA
| | - Hanqin Lei
- *Department of Physiology, Medical School, National and Kapodistrian University of Athens, Goudi-Athens, Greece; Department of Anatomy and Cell Biology, School of Dental Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA; Department of Kinesiology, McGill University, Montreal, Quebec, Canada; Pennsylvania Muscle Institute, University of Pennsylvania, Philadelphia, Pennsylvania, USA; and Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, Florida, USA
| | - Dilson E Rassier
- *Department of Physiology, Medical School, National and Kapodistrian University of Athens, Goudi-Athens, Greece; Department of Anatomy and Cell Biology, School of Dental Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA; Department of Kinesiology, McGill University, Montreal, Quebec, Canada; Pennsylvania Muscle Institute, University of Pennsylvania, Philadelphia, Pennsylvania, USA; and Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, Florida, USA
| | - Elisabeth R Barton
- *Department of Physiology, Medical School, National and Kapodistrian University of Athens, Goudi-Athens, Greece; Department of Anatomy and Cell Biology, School of Dental Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA; Department of Kinesiology, McGill University, Montreal, Quebec, Canada; Pennsylvania Muscle Institute, University of Pennsylvania, Philadelphia, Pennsylvania, USA; and Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, Florida, USA
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Spinazzola JM, Smith TC, Liu M, Luna EJ, Barton ER. Gamma-sarcoglycan is required for the response of archvillin to mechanical stimulation in skeletal muscle. Hum Mol Genet 2015; 24:2470-81. [PMID: 25605665 DOI: 10.1093/hmg/ddv008] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2014] [Accepted: 01/13/2015] [Indexed: 01/23/2023] Open
Abstract
Loss of gamma-sarcoglycan (γ-SG) induces muscle degeneration and signaling defects in response to mechanical load, and its absence is common to both Duchenne and limb girdle muscular dystrophies. Growing evidence suggests that aberrant signaling contributes to the disease pathology; however, the mechanisms of γ-SG-mediated mechanical signaling are poorly understood. To uncover γ-SG signaling pathway components, we performed yeast two-hybrid screens and identified the muscle-specific protein archvillin as a γ-SG and dystrophin interacting protein. Archvillin protein and message levels were significantly upregulated at the sarcolemma of murine γ-SG-null (gsg(-/-)) muscle but delocalized in dystrophin-deficient mdx muscle. Similar elevation of archvillin protein was observed in human quadriceps muscle lacking γ-SG. Reintroduction of γ-SG in gsg(-/-) muscle by rAAV injection restored archvillin levels to that of control C57 muscle. In situ eccentric contraction of tibialis anterior (TA) muscles from C57 mice caused ERK1/2 phosphorylation, nuclear activation of P-ERK1/2 and stimulus-dependent archvillin association with P-ERK1/2. In contrast, TA muscles from gsg(-/-) and mdx mice exhibited heightened P-ERK1/2 and increased nuclear P-ERK1/2 localization following eccentric contractions, but the archvillin-P-ERK1/2 association was completely ablated. These results position archvillin as a mechanically sensitive component of the dystrophin complex and demonstrate that signaling defects caused by loss of γ-SG occur both at the sarcolemma and in the nucleus.
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Affiliation(s)
- Janelle M Spinazzola
- Department of Anatomy and Cell Biology, School of Dental Medicine, Pennsylvania Muscle Institute, and
| | - Tara C Smith
- Department of Cell and Developmental Biology, University of Massachusetts Medical School, Worcester, MA 01655, USA
| | - Min Liu
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA and
| | - Elizabeth J Luna
- Department of Cell and Developmental Biology, University of Massachusetts Medical School, Worcester, MA 01655, USA
| | - Elisabeth R Barton
- Department of Anatomy and Cell Biology, School of Dental Medicine, Pennsylvania Muscle Institute, and
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Smith LR, Barton ER. SMASH - semi-automatic muscle analysis using segmentation of histology: a MATLAB application. Skelet Muscle 2014; 4:21. [PMID: 25937889 PMCID: PMC4417508 DOI: 10.1186/2044-5040-4-21] [Citation(s) in RCA: 143] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2014] [Accepted: 10/15/2014] [Indexed: 11/29/2022] Open
Abstract
Background Histological assessment of skeletal muscle tissue is commonly applied to many areas of skeletal muscle physiological research. Histological parameters including fiber distribution, fiber type, centrally nucleated fibers, and capillary density are all frequently quantified measures of skeletal muscle. These parameters reflect functional properties of muscle and undergo adaptation in many muscle diseases and injuries. While standard operating procedures have been developed to guide analysis of many of these parameters, the software to freely, efficiently, and consistently analyze them is not readily available. In order to provide this service to the muscle research community we developed an open source MATLAB script to analyze immunofluorescent muscle sections incorporating user controls for muscle histological analysis. Results The software consists of multiple functions designed to provide tools for the analysis selected. Initial segmentation and fiber filter functions segment the image and remove non-fiber elements based on user-defined parameters to create a fiber mask. Establishing parameters set by the user, the software outputs data on fiber size and type, centrally nucleated fibers, and other structures. These functions were evaluated on stained soleus muscle sections from 1-year-old wild-type and mdx mice, a model of Duchenne muscular dystrophy. In accordance with previously published data, fiber size was not different between groups, but mdx muscles had much higher fiber size variability. The mdx muscle had a significantly greater proportion of type I fibers, but type I fibers did not change in size relative to type II fibers. Centrally nucleated fibers were highly prevalent in mdx muscle and were significantly larger than peripherally nucleated fibers. Conclusions The MATLAB code described and provided along with this manuscript is designed for image processing of skeletal muscle immunofluorescent histological sections. The program allows for semi-automated fiber detection along with user correction. The output of the code provides data in accordance with established standards of practice. The results of the program have been validated using a small set of wild-type and mdx muscle sections. This program is the first freely available and open source image processing program designed to automate analysis of skeletal muscle histological sections.
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Affiliation(s)
- Lucas R Smith
- Department of Anatomy and Cell Biology, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA USA ; Pennsylvania Muscle Institute, University of Pennsylvania, Philadelphia, PA USA
| | - Elisabeth R Barton
- Department of Anatomy and Cell Biology, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA USA ; Pennsylvania Muscle Institute, University of Pennsylvania, Philadelphia, PA USA
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Abstract
It is virtually undisputed that IGF-I promotes cell growth and survival. However, the presence of several IGF-I isoforms, vast numbers of intracellular signaling components, and multiple receptors results in a complex and highly regulated system by which IGF-I actions are mediated. IGF-I has long been recognized as one of the critical factors for coordinating muscle growth, enhancing muscle repair, and increasing muscle mass and strength. How to optimize this panoply of pathways to drive anabolic processes in muscle as opposed to aberrant growth in other tissues is an area that deserves focus. This review will address how advances in the bioavailability, potency, and tissue response of IGF-I can provide new potential directions for skeletal muscle therapeutics.
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Affiliation(s)
- Anastassios Philippou
- Department of Physiology, Medical School, National and Kapodistrian University of Athens, Athens, Greece
| | - Elisabeth R Barton
- Department of Anatomy and Cell Biology, School of Dental Medicine, and Pennsylvania Muscle Institute, University of Pennsylvania, Philadelphia, PA, USA.
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Altamirano F, Perez CF, Liu M, Widrick J, Barton ER, Allen PD, Adams JA, Lopez JR. Whole body periodic acceleration is an effective therapy to ameliorate muscular dystrophy in mdx mice. PLoS One 2014; 9:e106590. [PMID: 25181488 PMCID: PMC4152333 DOI: 10.1371/journal.pone.0106590] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2014] [Accepted: 07/30/2014] [Indexed: 12/29/2022] Open
Abstract
Duchenne muscular dystrophy (DMD) is a genetic disorder caused by the absence of dystrophin in both skeletal and cardiac muscles. This leads to severe muscle degeneration, and dilated cardiomyopathy that produces patient death, which in most cases occurs before the end of the second decade. Several lines of evidence have shown that modulators of nitric oxide (NO) pathway can improve skeletal muscle and cardiac function in the mdx mouse, a mouse model for DMD. Whole body periodic acceleration (pGz) is produced by applying sinusoidal motion to supine humans and in standing conscious rodents in a headward-footward direction using a motion platform. It adds small pulses as a function of movement frequency to the circulation thereby increasing pulsatile shear stress to the vascular endothelium, which in turn increases production of NO. In this study, we examined the potential therapeutic properties of pGz for the treatment of skeletal muscle pathology observed in the mdx mouse. We found that pGz (480 cpm, 8 days, 1 hr per day) decreased intracellular Ca2+ and Na+ overload, diminished serum levels of creatine kinase (CK) and reduced intracellular accumulation of Evans Blue. Furthermore, pGz increased muscle force generation and expression of both utrophin and the carboxy-terminal PDZ ligand of nNOS (CAPON). Likewise, pGz (120 cpm, 12 h) applied in vitro to skeletal muscle myotubes reduced Ca2+ and Na+ overload, diminished abnormal sarcolemmal Ca2+ entry and increased phosphorylation of endothelial NOS. Overall, this study provides new insights into the potential therapeutic efficacy of pGz as a non-invasive and non-pharmacological approach for the treatment of DMD patients through activation of the NO pathway.
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Affiliation(s)
- Francisco Altamirano
- Department of Molecular Biosciences, School of Veterinary Medicine, University of California Davis, Davis, California, United States of America
| | - Claudio F. Perez
- Department of Anesthesiology Perioperative and Pain Medicine, Brigham & Women’s Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Min Liu
- Department of Physiology, Perleman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Jeffrey Widrick
- Division of Genetics and Program in Genomics, Boston Children’s Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Elisabeth R. Barton
- Anatomy and Cell Biology, School of Dental Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Paul D. Allen
- Department of Molecular Biosciences, School of Veterinary Medicine, University of California Davis, Davis, California, United States of America
- Department of Anesthesiology Perioperative and Pain Medicine, Brigham & Women’s Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Jose A. Adams
- Division of Neonatology, Mount Sinai Medical Center, Miami, Florida, United States of America
| | - Jose R. Lopez
- Department of Molecular Biosciences, School of Veterinary Medicine, University of California Davis, Davis, California, United States of America
- Department of Anesthesiology Perioperative and Pain Medicine, Brigham & Women’s Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
- * E-mail:
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Moorwood C, Philippou A, Spinazzola J, Keyser B, Macarak EJ, Barton ER. Absence of γ-sarcoglycan alters the response of p70S6 kinase to mechanical perturbation in murine skeletal muscle. Skelet Muscle 2014; 4:13. [PMID: 25024843 PMCID: PMC4095884 DOI: 10.1186/2044-5040-4-13] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2014] [Accepted: 05/29/2014] [Indexed: 12/18/2022] Open
Abstract
Background The dystrophin glycoprotein complex (DGC) is located at the sarcolemma of muscle fibers, providing structural integrity. Mutations in and loss of DGC proteins cause a spectrum of muscular dystrophies. When only the sarcoglycan subcomplex is absent, muscles display severe myofiber degeneration, but little susceptibility to contractile damage, suggesting that disease occurs not by structural deficits but through aberrant signaling, namely, loss of normal mechanotransduction signaling through the sarcoglycan complex. We extended our previous studies on mechanosensitive, γ-sarcoglycan-dependent ERK1/2 phosphorylation, to determine whether additional pathways are altered with the loss of γ-sarcoglycan. Methods We examined mechanotransduction in the presence and absence of γ-sarcoglycan, using C2C12 myotubes, and primary cultures and isolated muscles from C57Bl/6 (C57) and γ-sarcoglycan-null (γ-SG-/-) mice. All were subjected to cyclic passive stretch. Signaling protein phosphorylation was determined by immunoblotting of lysates from stretched and non-stretched samples. Calcium dependence was assessed by maintaining muscles in calcium-free or tetracaine-supplemented Ringer’s solution. Dependence on mTOR was determined by stretching isolated muscles in the presence or absence of rapamycin. Results C2C12 myotube stretch caused a robust increase in P-p70S6K, but decreased P-FAK and P-ERK2. Neither Akt nor ERK1 were responsive to passive stretch. Similar but non-significant trends were observed in C57 primary cultures in response to stretch, and γ-SG-/- cultures displayed no p70S6K response. In contrast, in isolated muscles, p70S6K was mechanically responsive. Basal p70S6K activation was elevated in muscles of γ-SG-/- mice, in a calcium-independent manner. p70S6K activation increased with stretch in both C57 and γ-SG-/- isolated muscles, and was sustained in γ-SG-/- muscles, unlike the transient response in C57 muscles. Rapamycin treatment blocked all of p70S6K activation in stretched C57 muscles, and reduced downstream S6RP phosphorylation. However, even though rapamycin treatment decreased p70S6K activation in stretched γ-SG-/- muscles, S6RP phosphorylation remained elevated. Conclusions p70S6K is an important component of γ-sarcoglycan-dependent mechanotransduction in skeletal muscle. Our results suggest that loss of γ-sarcoglycan uncouples the response of p70S6K to stretch and implies that γ-sarcoglycan is important for inactivation of this pathway. Overall, we assert that altered load-sensing mechanisms exist in muscular dystrophies where the sarcoglycans are absent.
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Affiliation(s)
- Catherine Moorwood
- Department of Anatomy and Cell Biology, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA, USA ; Pennsylvania Muscle Institute, University of Pennsylvania, Philadelphia, PA, USA
| | - Anastassios Philippou
- Department of Anatomy and Cell Biology, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA, USA ; Pennsylvania Muscle Institute, University of Pennsylvania, Philadelphia, PA, USA ; Current address: Department of Physiology, Medical School, National and Kapodistrian University of Athens, Goudi, Athens, Greece
| | - Janelle Spinazzola
- Department of Anatomy and Cell Biology, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA, USA ; Pennsylvania Muscle Institute, University of Pennsylvania, Philadelphia, PA, USA
| | - Benjamin Keyser
- Department of Anatomy and Cell Biology, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Edward J Macarak
- Department of Anatomy and Cell Biology, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA, USA ; Current address: Department of Dermatology and Cutaneous Biology, Jefferson University College of Medicine, Philadelphia, PA, USA
| | - Elisabeth R Barton
- Department of Anatomy and Cell Biology, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA, USA ; Pennsylvania Muscle Institute, University of Pennsylvania, Philadelphia, PA, USA
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Abstract
Duchenne muscular dystrophy (DMD) is a devastating muscle wasting disease caused by mutations in dystrophin. Several downstream consequences of dystrophin deficiency are triggers of endoplasmic reticulum (ER) stress, including loss of calcium homeostasis, hypoxia and oxidative stress. During ER stress, misfolded proteins accumulate in the ER lumen and the unfolded protein response (UPR) is triggered, leading to adaptation or apoptosis. We hypothesized that ER stress is heightened in dystrophic muscles and contributes to the pathology of DMD. We observed increases in the ER stress markers BiP and cleaved caspase-4 in DMD patient biopsies, compared with controls, and an increase in multiple UPR pathways in muscles of the dystrophin-deficient mdx mouse. We then crossed mdx mice with mice null for caspase-12, the murine equivalent of human caspase-4, which are resistant to ER stress. We found that deleting caspase-12 preserved mdx muscle function, resulting in a 75% recovery of both specific force generation and resistance to eccentric contractions. The compensatory hypertrophy normally found in mdx muscles was normalized in the absence of caspase-12; this was found to be due to decreased fibre sizes, and not to a fibre type shift or a decrease in fibrosis. Fibre central nucleation was not significantly altered in the absence of caspase-12, but muscle fibre degeneration found in the mdx mouse was reduced almost to wild-type levels. In conclusion, we have identified heightened ER stress and abnormal UPR signalling as novel contributors to the dystrophic phenotype. Caspase-4 is therefore a potential therapeutic target for DMD.
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Affiliation(s)
- Catherine Moorwood
- Department of Anatomy and Cell Biology, University of Pennsylvania School of Dental Medicine, Philadelphia, PA, USA and Pennsylvania Muscle Institute, University of Pennsylvania, Philadelphia, PA, USA
| | - Elisabeth R Barton
- Department of Anatomy and Cell Biology, University of Pennsylvania School of Dental Medicine, Philadelphia, PA, USA and Pennsylvania Muscle Institute, University of Pennsylvania, Philadelphia, PA, USA
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Brisson BK, Spinazzola J, Park S, Barton ER. Viral expression of insulin-like growth factor I E-peptides increases skeletal muscle mass but at the expense of strength. Am J Physiol Endocrinol Metab 2014; 306:E965-74. [PMID: 24569593 PMCID: PMC3989742 DOI: 10.1152/ajpendo.00008.2014] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Insulin-like growth factor I (IGF-I) is a protein that regulates and promotes growth in skeletal muscle. The IGF-I precursor polypeptide contains a COOH-terminal extension called the E-peptide. Alternative splicing in the rodent produces two isoforms, IA and IB, where the mature IGF-I in both isoforms is identical yet the E-peptides, EA and EB, share less than 50% homology. Recent in vitro studies show that the E-peptides can enhance IGF-I signaling, leading to increased myoblast cell proliferation and migration. To determine the significance of these actions in vivo and to evaluate if they are physiologically beneficial, EA and EB were expressed in murine skeletal muscle via viral vectors. The viral constructs ensured production of E-peptides without the influence of additional IGF-I through an inactivating mutation in mature IGF-I. E-peptide expression altered ERK1/2 and Akt phosphorylation and increased satellite cell proliferation. EB expression resulted in significant muscle hypertrophy that was IGF-I receptor dependent. However, the increased mass was associated with a loss of muscle strength. EA and EB have similar effects in skeletal muscle signaling and on satellite cells, but EB is more potent at increasing muscle mass. Although sustained EB expression may drive hypertrophy, there are significant physiological consequences for muscle.
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Affiliation(s)
- Becky K Brisson
- Department of Anatomy and Cell Biology, School of Dental Medicine, and Pennsylvania Muscle Institute, University of Pennsylvania, Philadelphia, Pennsylvania
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Abstract
Many skeletal muscle diseases are associated with progressive fibrosis leading to impaired muscle function. Collagen within the extracellular matrix is the primary structural protein providing a mechanical scaffold for cells within tissues. During fibrosis collagen not only increases in amount but also undergoes posttranslational changes that alter its organization that is thought to contribute to tissue stiffness. Little, however, is known about collagen organization in fibrotic muscle and its consequences for function. To investigate the relationship between collagen content and organization with muscle mechanical properties, we studied mdx mice, a model for Duchenne muscular dystrophy (DMD) that undergoes skeletal muscle fibrosis, and age-matched control mice. We determined collagen content both histologically, with picosirius red staining, and biochemically, with hydroxyproline quantification. Collagen content increased in the mdx soleus and diaphragm muscles, which was exacerbated by age in the diaphragm. Collagen packing density, a parameter of collagen organization, was determined using circularly polarized light microscopy of picosirius red-stained sections. Extensor digitorum longus (EDL) and soleus muscle had proportionally less dense collagen in mdx muscle, while the diaphragm did not change packing density. The mdx muscles had compromised strength as expected, yet only the EDL had a significantly increased elastic stiffness. The EDL and diaphragm had increased dynamic stiffness and a change in relative viscosity. Unexpectedly, passive stiffness did not correlate with collagen content and only weakly correlated with collagen organization. We conclude that muscle fibrosis does not lead to increased passive stiffness and that collagen content is not predictive of muscle stiffness.
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Affiliation(s)
- Lucas R Smith
- Department of Anatomy and Cell Biology, School of Dental Medicine, Pennsylvania Muscle Institute, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Elisabeth R Barton
- Department of Anatomy and Cell Biology, School of Dental Medicine, Pennsylvania Muscle Institute, University of Pennsylvania, Philadelphia, Pennsylvania
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Park S, Brisson BK, Liu M, Spinazzola JM, Barton ER. Mature IGF-I excels in promoting functional muscle recovery from disuse atrophy compared with pro-IGF-IA. J Appl Physiol (1985) 2013; 116:797-806. [PMID: 24371018 DOI: 10.1152/japplphysiol.00955.2013] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Prolonged disuse of skeletal muscle results in atrophy, and once physical activity is resumed, there is increased susceptibility to injury. Insulin-like growth factor-I (IGF-I) is considered a potential therapeutic target to attenuate atrophy during unloading and to enhance rehabilitation upon reloading of skeletal muscles, due to its multipronged actions on satellite cell proliferation, differentiation, and survival, as well as its actions on muscle fibers to boost protein synthesis and inhibit protein degradation. However, the form of IGF-I delivered may alter the success of treatment. Using the hindlimb suspension model of disuse atrophy, we compared the efficacy of two IGF-I forms in protection against atrophy and enhancement of recovery: mature IGF-I (IGF-IS) lacking the COOH-terminal extension, called the E-peptide, and IGF-IA, which is the predominant form retaining the E-peptide. Self-complementary adeno-associated virus harboring the murine Igf1 cDNA constructs were delivered to hindlimbs of adult female C57BL6 mice 3 days prior to hindlimb suspension. Hindlimb muscles were unloaded for 7 days and then reloaded for 3, 7, and 14 days. Loss of muscle mass following suspension was not prevented by either IGF-I construct. However, IGF-IS expression maintained soleus muscle force production. Further, IGF-IS treatment caused rapid recovery of muscle fiber morphology during reloading and maintained muscle strength. Analysis of gene expression revealed that IGF-IS expression accelerated the downregulation of atrophy-related genes compared with untreated or IGF-IA-treated samples. We conclude that mature-IGF-I may be a better option than pro-IGF-IA to promote skeletal muscle recovery following disuse atrophy.
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Affiliation(s)
- Soohyun Park
- Department of Anatomy and Cell Biology, School of Dental Medicine
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Zou Y, Zwolanek D, Izu Y, Gandhy S, Schreiber G, Brockmann K, Devoto M, Tian Z, Hu Y, Veit G, Meier M, Stetefeld J, Hicks D, Straub V, Voermans NC, Birk DE, Barton ER, Koch M, Bönnemann CG. Recessive and dominant mutations in COL12A1 cause a novel EDS/myopathy overlap syndrome in humans and mice. Hum Mol Genet 2013; 23:2339-52. [PMID: 24334604 DOI: 10.1093/hmg/ddt627] [Citation(s) in RCA: 82] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Collagen VI-related myopathies are disorders of connective tissue presenting with an overlap phenotype combining clinical involvement from the muscle and from the connective tissue. Not all patients displaying related overlap phenotypes between muscle and connective tissue have mutations in collagen VI. Here, we report a homozygous recessive loss of function mutation and a de novo dominant mutation in collagen XII (COL12A1) as underlying a novel overlap syndrome involving muscle and connective tissue. Two siblings homozygous for a loss of function mutation showed widespread joint hyperlaxity combined with weakness precluding independent ambulation, while the patient with the de novo missense mutation was more mildly affected, showing improvement including the acquisition of walking. A mouse model with inactivation of the Col12a1 gene showed decreased grip strength, a delay in fiber-type transition and a deficiency in passive force generation while the muscle seems more resistant to eccentric contraction induced force drop, indicating a role for a matrix-based passive force-transducing elastic element in the generation of the weakness. This new muscle connective tissue overlap syndrome expands on the emerging importance of the muscle extracellular matrix in the pathogenesis of muscle disease.
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Affiliation(s)
- Yaqun Zou
- Neuromuscular and Neurogenetic Disorders of Childhood Section, National Institute of Neurological Disorders and Stroke, NIH, Bethesda, MD, USA
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Xu C, Tabebordbar M, Iovino S, Ciarlo C, Liu J, Castiglioni A, Price E, Liu M, Barton ER, Kahn CR, Wagers AJ, Zon LI. A zebrafish embryo culture system defines factors that promote vertebrate myogenesis across species. Cell 2013; 155:909-921. [PMID: 24209627 PMCID: PMC3902670 DOI: 10.1016/j.cell.2013.10.023] [Citation(s) in RCA: 133] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2013] [Revised: 08/29/2013] [Accepted: 10/11/2013] [Indexed: 01/05/2023]
Abstract
Ex vivo expansion of satellite cells and directed differentiation of pluripotent cells to mature skeletal muscle have proved difficult challenges for regenerative biology. Using a zebrafish embryo culture system with reporters of early and late skeletal muscle differentiation, we examined the influence of 2,400 chemicals on myogenesis and identified six that expanded muscle progenitors, including three GSK3β inhibitors, two calpain inhibitors, and one adenylyl cyclase activator, forskolin. Forskolin also enhanced proliferation of mouse satellite cells in culture and maintained their ability to engraft muscle in vivo. A combination of bFGF, forskolin, and the GSK3β inhibitor BIO induced skeletal muscle differentiation in human induced pluripotent stem cells (iPSCs) and produced engraftable myogenic progenitors that contributed to muscle repair in vivo. In summary, these studies reveal functionally conserved pathways regulating myogenesis across species and identify chemical compounds that expand mouse satellite cells and differentiate human iPSCs into engraftable muscle.
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Affiliation(s)
- Cong Xu
- Division of Hematology/Oncology, Children’s Hospital Boston and Dana-Farber Cancer Institute, Boston, MA 02115, USA
- Howard Hughes Medical Institute, Harvard Stem Cell Institute, Boston, MA 02115, USA
- Harvard Medical School, Boston, MA 02115, USA
| | - Mohammadsharif Tabebordbar
- Howard Hughes Medical Institute, Harvard Stem Cell Institute, Boston, MA 02115, USA
- Harvard Medical School, Boston, MA 02115, USA
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA 02138, USA
| | - Salvatore Iovino
- Harvard Medical School, Boston, MA 02115, USA
- Joslin Diabetes Center, Boston, MA 02115, USA
| | - Christie Ciarlo
- Division of Hematology/Oncology, Children’s Hospital Boston and Dana-Farber Cancer Institute, Boston, MA 02115, USA
- Howard Hughes Medical Institute, Harvard Stem Cell Institute, Boston, MA 02115, USA
- Harvard Medical School, Boston, MA 02115, USA
| | - Jingxia Liu
- Division of Hematology/Oncology, Children’s Hospital Boston and Dana-Farber Cancer Institute, Boston, MA 02115, USA
- Howard Hughes Medical Institute, Harvard Stem Cell Institute, Boston, MA 02115, USA
- Harvard Medical School, Boston, MA 02115, USA
| | - Alessandra Castiglioni
- Howard Hughes Medical Institute, Harvard Stem Cell Institute, Boston, MA 02115, USA
- Joslin Diabetes Center, Boston, MA 02115, USA
- Vita-Salute San Raffaele University, Milan, 20132, Italy
| | - Emily Price
- Division of Hematology/Oncology, Children’s Hospital Boston and Dana-Farber Cancer Institute, Boston, MA 02115, USA
- Howard Hughes Medical Institute, Harvard Stem Cell Institute, Boston, MA 02115, USA
- Harvard Medical School, Boston, MA 02115, USA
| | - Min Liu
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Elisabeth R. Barton
- Department of Anatomy and Cell Biology, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - C. Ronald Kahn
- Harvard Medical School, Boston, MA 02115, USA
- Joslin Diabetes Center, Boston, MA 02115, USA
| | - Amy J. Wagers
- Howard Hughes Medical Institute, Harvard Stem Cell Institute, Boston, MA 02115, USA
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA 02138, USA
- Joslin Diabetes Center, Boston, MA 02115, USA
| | - Leonard I. Zon
- Division of Hematology/Oncology, Children’s Hospital Boston and Dana-Farber Cancer Institute, Boston, MA 02115, USA
- Howard Hughes Medical Institute, Harvard Stem Cell Institute, Boston, MA 02115, USA
- Harvard Medical School, Boston, MA 02115, USA
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Selsby JT, Acosta P, Sleeper MM, Barton ER, Sweeney HL. Long-term wheel running compromises diaphragm function but improves cardiac and plantarflexor function in the mdx mouse. J Appl Physiol (1985) 2013; 115:660-6. [PMID: 23823150 DOI: 10.1152/japplphysiol.00252.2013] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Dystrophin-deficient muscles suffer from free radical injury, mitochondrial dysfunction, apoptosis, and inflammation, among other pathologies that contribute to muscle fiber injury and loss, leading to wheelchair confinement and death in the patient. For some time, it has been appreciated that endurance training has the potential to counter many of these contributing factors. Correspondingly, numerous investigations have shown improvements in limb muscle function following endurance training in mdx mice. However, the effect of long-term volitional wheel running on diaphragm and cardiac function is largely unknown. Our purpose was to determine the extent to which long-term endurance exercise affected dystrophic limb, diaphragm, and cardiac function. Diaphragm specific tension was reduced by 60% (P < 0.05) in mice that performed 1 yr of volitional wheel running compared with sedentary mdx mice. Dorsiflexor mass (extensor digitorum longus and tibialis anterior) and function (extensor digitorum longus) were not altered by endurance training. In mice that performed 1 yr of volitional wheel running, plantarflexor mass (soleus and gastrocnemius) was increased and soleus tetanic force was increased 36%, while specific tension was similar in wheel-running and sedentary groups. Cardiac mass was increased 15%, left ventricle chamber size was increased 20% (diastole) and 18% (systole), and stroke volume was increased twofold in wheel-running compared with sedentary mdx mice. These data suggest that the dystrophic heart may undergo positive exercise-induced remodeling and that limb muscle function is largely unaffected. Most importantly, however, as the diaphragm most closely recapitulates the human disease, these data raise the possibility of exercise-mediated injury in dystrophic skeletal muscle.
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Affiliation(s)
- Joshua T Selsby
- Department of Animal Science, College of Agriculture and Life Sciences, Iowa State University, Ames, Iowa
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Lei H, Leong D, Smith LR, Barton ER. Matrix metalloproteinase 13 is a new contributor to skeletal muscle regeneration and critical for myoblast migration. Am J Physiol Cell Physiol 2013; 305:C529-38. [PMID: 23761625 DOI: 10.1152/ajpcell.00051.2013] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Efficient skeletal muscle repair and regeneration require coordinated remodeling of the extracellular matrix (ECM). Previous reports have indicated that matrix metalloproteinases (MMPs) play the pivotal role in ECM remodeling during muscle regeneration. The goal of the current study was to determine if the interstitial collagenase MMP-13 was involved in the muscle repair process. Using intramuscular cardiotoxin injections to induce acute muscle injury, we found that MMP-13 expression and activity transiently increased during the regeneration process. In addition, in muscles from mdx mice, which exhibit chronic injury, MMP-13 expression and protein levels were elevated. In differentiating C2C12 cells, a murine myoblast cell line, Mmp13 expression was most pronounced after myoblast fusion and during myotube formation. Using pharmacological inhibition of MMP-13 to test whether MMP-13 activity is necessary for the proliferation, differentiation, migration, and fusion of C2C12 cells, we found a dramatic blockade of myoblast migration, as well as a delay in differentiation. In contrast, C2C12 cells with stable overexpression of MMP-13 showed enhanced migration, without affecting myoblast maturation. Taken together, these results support a primary role for MMP-13 in myoblast migration that leads to secondary effects on differentiation.
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Affiliation(s)
- Hanqin Lei
- Department of Anatomy and Cell Biology, School of Dental Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
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Abstract
Several physiological activities have been assigned to E-peptides derived from pre-pro-insulin-like growth factor (IGF1) processing; however, the whole range of the E-peptides' functions is still unknown. The objective of this study was to investigate human Eb peptide (hEb) in terms of its bioactivity, cellular localization, and intracellular trafficking using human cancer cells. Human Eb fused with red fluorescence protein (RFP) or green fluorescence protein (GFP) localizes strongly to nucleoli and to a lesser extent to nuclei of HeLa and U2-OS cells. Mutagenesis of hEb nucleolus localization sequence (NoLS) leads to its partial delocalization from nuclei and nucleoli to cytoplasm of transfected cells. Thus, NoLS is not sufficient for the hEb to be localized in nucleoli of the cells and a different mechanism may be involved in hEb targeting. A BrdU ELISA showed that the proliferation index of cells expressing hEb hybrid proteins increased up to 28%. For comparison, the same assay was performed using HeLa cells treated extracellularly with synthetic hEb. A significant increase in the proliferation index was observed (41-58% for concentrations ranging from 10-100 nM, respectively). Additionally, a cell migration assay was performed using stable U2-OS cell lines expressing hEb fused with RFP or RFP alone as a negative control. The migration index of hEb expressing cells was 38.3% greater. The increase in cell proliferation index and in motile properties of hEb expressing cells demonstrate that hEb is more than a pre-pro-IGF1b processing product, and has intrinsic activity of biological significance.
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Affiliation(s)
- J Durzyńska
- Department of Anatomy and Cell Biology, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA, USA.
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Selsby JT, Acosta P, Sleeper MM, Barton ER, Lee Sweeney H. Long‐term wheel running improves cardiac function but has negative consequences for diaphragmatic function in the mdx mouse. FASEB J 2013. [DOI: 10.1096/fasebj.27.1_supplement.712.16] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | - Pedro Acosta
- PhysiologyUniveristy of PennsylvaniaPhiladelphiaPA
| | - Meg M. Sleeper
- Clinical StudiesUniveristy of PennsylvaniaPhiladelphiaPA
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Durzyńska J, Philippou A, Brisson BK, Nguyen-McCarty M, Barton ER. The pro-forms of insulin-like growth factor I (IGF-I) are predominant in skeletal muscle and alter IGF-I receptor activation. Endocrinology 2013; 154:1215-24. [PMID: 23407451 PMCID: PMC3578996 DOI: 10.1210/en.2012-1992] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
IGF-I is a key regulator of muscle development and growth. The pre-pro-peptide produced by the Igf1gene undergoes several posttranslational processing steps to result in a secreted mature protein, which is thought to be the obligate ligand for the IGF-I receptor (IGF-IR). The goals of this study were to determine what forms of IGF-I exist in skeletal muscle, and whether the mature IGF-I protein was the only form able to activate the IGF-IR. We measured the proportion of IGF-I species in murine skeletal muscle and found that the predominant forms were nonglycosylated pro-IGF-I and glycosylated pro-IGF-I, which retained the C-terminal E peptide extension, instead of mature IGF-I. These forms were validated using samples subjected to viral expression of IGF-I combined with furin and glycosidase digestion. To determine whether the larger molecular weight IGF-I forms were also ligands for the IGF-IR, we generated each specific form through transient transfection of 3T3 cells and used the enriched media to perform kinase receptor activation assays. Compared with mature IGF-I, nonglycosylated pro-IGF-I had similar ability to activate the IGF-IR, whereas glycosylation of pro-IGF-I significantly reduced receptor activation. Thus, it is important to understand not only the quantity, but also the proportion of IGF-I forms produced, to evaluate the true biological activity of this growth factor.
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Affiliation(s)
- Julia Durzyńska
- Department of Anatomy and Cell Biology, School of Dental Medicine, and Pennsylvania Muscle Institute, University of Pennsylvania, Philadelphia, PA 19104, USA
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