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Korb A, Tajbakhsh S, Comai GE. Functional specialisation and coordination of myonuclei. Biol Rev Camb Philos Soc 2024; 99:1164-1195. [PMID: 38477382 DOI: 10.1111/brv.13063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2023] [Revised: 01/30/2024] [Accepted: 02/02/2024] [Indexed: 03/14/2024]
Abstract
Myofibres serve as the functional unit for locomotion, with the sarcomere as fundamental subunit. Running the entire length of this structure are hundreds of myonuclei, located at the periphery of the myofibre, juxtaposed to the plasma membrane. Myonuclear specialisation and clustering at the centre and ends of the fibre are known to be essential for muscle contraction, yet the molecular basis of this regionalisation has remained unclear. While the 'myonuclear domain hypothesis' helped explain how myonuclei can independently govern large cytoplasmic territories, novel technologies have provided granularity on the diverse transcriptional programs running simultaneously within the syncytia and added a new perspective on how myonuclei communicate. Building upon this, we explore the critical cellular and molecular sources of transcriptional and functional heterogeneity within myofibres, discussing the impact of intrinsic and extrinsic factors on myonuclear programs. This knowledge provides new insights for understanding muscle development, repair, and disease, but also opens avenues for the development of novel and precise therapeutic approaches.
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Affiliation(s)
- Amaury Korb
- Institut Pasteur, Université Paris Cité, CNRS UMR 3738, Stem Cells & Development Unit, 25 rue du Dr. Roux, Institut Pasteur, Paris, F-75015, France
| | - Shahragim Tajbakhsh
- Institut Pasteur, Université Paris Cité, CNRS UMR 3738, Stem Cells & Development Unit, 25 rue du Dr. Roux, Institut Pasteur, Paris, F-75015, France
| | - Glenda E Comai
- Institut Pasteur, Université Paris Cité, CNRS UMR 3738, Stem Cells & Development Unit, 25 rue du Dr. Roux, Institut Pasteur, Paris, F-75015, France
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2
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Schmidt L, Saynisch M, Hoegsbjerg C, Schmidt A, Mackey A, Lackmann JW, Müller S, Koch M, Brachvogel B, Kjaer M, Antczak P, Krüger M. Spatial proteomics of skeletal muscle using thin cryosections reveals metabolic adaptation at the muscle-tendon transition zone. Cell Rep 2024; 43:114374. [PMID: 38900641 DOI: 10.1016/j.celrep.2024.114374] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2023] [Revised: 04/05/2024] [Accepted: 05/31/2024] [Indexed: 06/22/2024] Open
Abstract
Morphological studies of skeletal muscle tissue provide insights into the architecture of muscle fibers, the surrounding cells, and the extracellular matrix (ECM). However, a spatial proteomics analysis of the skeletal muscle including the muscle-tendon transition zone is lacking. Here, we prepare cryotome muscle sections of the mouse soleus muscle and measure each slice using short liquid chromatography-mass spectrometry (LC-MS) gradients. We generate 3,000 high-resolution protein profiles that serve as the basis for a network analysis to reveal the complex architecture of the muscle-tendon junction. Among the protein profiles that increase from muscle to tendon, we find proteins related to neuronal activity, fatty acid biosynthesis, and the renin-angiotensin system (RAS). Blocking the RAS in cultured mouse tenocytes using losartan reduces the ECM synthesis. Overall, our analysis of thin cryotome sections provides a spatial proteome of skeletal muscle and reveals that the RAS acts as an additional regulator of the matrix within muscle-tendon junctions.
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Affiliation(s)
- Luisa Schmidt
- Institute for Genetics, Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), Cologne, Germany
| | - Michael Saynisch
- Institute for Genetics, Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), Cologne, Germany
| | - Christian Hoegsbjerg
- Institute of Sports Medicine Copenhagen, Department of Orthopaedic Surgery, Copenhagen University Hospital - Bispebjerg and Frederiksberg, Copenhagen, Denmark; Part of IOC Research Center Copenhagen and Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | | | - Abigail Mackey
- Institute of Sports Medicine Copenhagen, Department of Orthopaedic Surgery, Copenhagen University Hospital - Bispebjerg and Frederiksberg, Copenhagen, Denmark; Part of IOC Research Center Copenhagen and Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Jan-Wilm Lackmann
- Institute for Genetics, Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), Cologne, Germany
| | - Stefan Müller
- Institute for Genetics, Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), Cologne, Germany
| | - Manuel Koch
- Institute for Dental Research and Oral Musculoskeletal Biology, Center for Biochemistry, Medical Faculty, University of Cologne, Cologne, Germany
| | - Bent Brachvogel
- Department of Pediatrics and Adolescent Medicine, Experimental Neonatology, Medical Faculty, University of Cologne, Cologne, Germany; Center for Biochemistry, Medical Faculty, University of Cologne, Cologne, Germany
| | - Michael Kjaer
- Institute of Sports Medicine Copenhagen, Department of Orthopaedic Surgery, Copenhagen University Hospital - Bispebjerg and Frederiksberg, Copenhagen, Denmark; Part of IOC Research Center Copenhagen and Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Philipp Antczak
- Institute for Genetics, Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), Cologne, Germany; Center for Molecular Medicine (CMMC), University of Cologne, 50931 Cologne, Germany.
| | - Marcus Krüger
- Institute for Genetics, Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), Cologne, Germany; Center for Molecular Medicine (CMMC), University of Cologne, 50931 Cologne, Germany.
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3
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Josvai M, Polyak E, Kalluri M, Robertson S, Crone WC, Suzuki M. An engineered in vitro model of the human myotendinous junction. Acta Biomater 2024; 180:279-294. [PMID: 38604466 PMCID: PMC11088524 DOI: 10.1016/j.actbio.2024.04.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2023] [Revised: 03/12/2024] [Accepted: 04/03/2024] [Indexed: 04/13/2024]
Abstract
The myotendinous junction (MTJ) is a vulnerable region at the interface of skeletal muscle and tendon that forms an integrated mechanical unit. This study presents a technique for the spatially restrictive co-culture of human embryonic stem cell (hESC)-derived skeletal myocytes and primary tenocytes for two-dimensional modeling of the MTJ. Micropatterned lanes of extracellular matrix and a 2-well culture chamber define the initial regions of occupation. On day 1, both lines occupy less than 20 % of the initially vacant interstitial zone, referred to henceforth as the junction. Myocyte-tenocyte interdigitations are observed by day 7. Immunocytochemistry reveals enhanced organization and alignment of patterned myocyte and tenocyte features, as well as differential expression of multiple MTJ markers. On day 24, electrically stimulated junction myocytes demonstrate negative contractile strains, while positive tensile strains are exhibited by mechanically passive tenocytes at the junction. Unpatterned tenocytes distal to the junction experience significantly decreased strains in comparison to cells at the interface. Unpatterned myocytes have impaired organization and uncoordinated contractile behavior. These findings suggest that this platform is capable of inducing myocyte-tenocyte junction formation and mechanical coupling similar to the native MTJ, showing transduction of force across the cell-cell interface. STATEMENT OF SIGNIFICANCE: The myotendinous junction (MTJ) is an integrated structure that transduces force across the muscle-tendon boundary, making the region vulnerable to strain injury. Despite the clinical relevance, previous in vitro models of the MTJ lack the structure and mechanical accuracy of the native tissue and have difficulty transmitting force across the cell-cell interface. This study demonstrates an in vitro model of the MTJ, using spatially restrictive cues to inform human myocyte-tenocyte interactions and architecture. The model expressed MTJ markers and developed anisotropic myocyte-tenocyte integrations that resemble the native tissue and allow for force transduction from contracting myocytes to passive tenocyte regions. As such, this study presents a system capable of investigating development, injury, and pathology in the human MTJ.
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Affiliation(s)
- Mitchell Josvai
- Department of Biomedical Engineering, University of Wisconsin-Madison, Engineering Centers Building, 2126, 1550 Engineering Dr, Madison WI 53706, USA; Wisconsin Institute for Discovery, University of Wisconsin-Madison, 330 N Orchard St, Madison, WI 53715, USA
| | - Erzsebet Polyak
- Department of Comparative Biosciences, University of Wisconsin-Madison, Veterinary Medicine Bldg, 2015 Linden Dr, Madison, WI 53706, USA
| | - Meghana Kalluri
- Department of Biomedical Engineering, University of Wisconsin-Madison, Engineering Centers Building, 2126, 1550 Engineering Dr, Madison WI 53706, USA; Wisconsin Institute for Discovery, University of Wisconsin-Madison, 330 N Orchard St, Madison, WI 53715, USA
| | - Samantha Robertson
- Department of Comparative Biosciences, University of Wisconsin-Madison, Veterinary Medicine Bldg, 2015 Linden Dr, Madison, WI 53706, USA
| | - Wendy C Crone
- Department of Biomedical Engineering, University of Wisconsin-Madison, Engineering Centers Building, 2126, 1550 Engineering Dr, Madison WI 53706, USA; Wisconsin Institute for Discovery, University of Wisconsin-Madison, 330 N Orchard St, Madison, WI 53715, USA; The Stem Cell and Regenerative Medicine Center, University of Wisconsin-Madison, 1111 Highland Ave, Madison, WI 53705, USA; Department of Nuclear Engineering and Engineering Physics, University of Wisconsin-Madison, 1500 Engineering Drive, Madison, WI 53706, USA; Department of Mechanical Engineering, University of Wisconsin-Madison, 1513 University Avenue, Madison, WI 53706, USA.
| | - Masatoshi Suzuki
- Department of Biomedical Engineering, University of Wisconsin-Madison, Engineering Centers Building, 2126, 1550 Engineering Dr, Madison WI 53706, USA; Department of Comparative Biosciences, University of Wisconsin-Madison, Veterinary Medicine Bldg, 2015 Linden Dr, Madison, WI 53706, USA; The Stem Cell and Regenerative Medicine Center, University of Wisconsin-Madison, 1111 Highland Ave, Madison, WI 53705, USA.
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4
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Tong S, Sun Y, Kuang B, Wang M, Chen Z, Zhang W, Chen J. A Comprehensive Review of Muscle-Tendon Junction: Structure, Function, Injury and Repair. Biomedicines 2024; 12:423. [PMID: 38398025 PMCID: PMC10886980 DOI: 10.3390/biomedicines12020423] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2023] [Revised: 01/31/2024] [Accepted: 02/08/2024] [Indexed: 02/25/2024] Open
Abstract
The muscle-tendon junction (MTJ) is a highly specific tissue interface where the muscle's fascia intersects with the extracellular matrix of the tendon. The MTJ functions as the particular structure facilitating the transmission of force from contractive muscle fibers to the skeletal system, enabling movement. Considering that the MTJ is continuously exposed to constant mechanical forces during physical activity, it is susceptible to injuries. Ruptures at the MTJ often accompany damage to both tendon and muscle tissues. In this review, we attempt to provide a precise definition of the MTJ, describe its subtle structure in detail, and introduce therapeutic approaches related to MTJ tissue engineering. We hope that our detailed illustration of the MTJ and summary of the representative research achievements will help researchers gain a deeper understanding of the MTJ and inspire fresh insights and breakthroughs for future research.
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Affiliation(s)
- Siqi Tong
- School of Medicine, Southeast University, Nanjing 210009, China
- Center for Stem Cell and Regenerative Medicine, Southeast University, Nanjing 210009, China
| | - Yuzhi Sun
- Center for Stem Cell and Regenerative Medicine, Southeast University, Nanjing 210009, China
- Department of Orthopaedic Surgery, Institute of Digital Medicine, Nanjing First Hospital, Nanjing Medical University, Nanjing 210006, China
| | - Baian Kuang
- School of Medicine, Southeast University, Nanjing 210009, China
- Center for Stem Cell and Regenerative Medicine, Southeast University, Nanjing 210009, China
| | - Mingyue Wang
- School of Medicine, Southeast University, Nanjing 210009, China
- Center for Stem Cell and Regenerative Medicine, Southeast University, Nanjing 210009, China
| | - Zhixuan Chen
- School of Medicine, Southeast University, Nanjing 210009, China
- Center for Stem Cell and Regenerative Medicine, Southeast University, Nanjing 210009, China
| | - Wei Zhang
- School of Medicine, Southeast University, Nanjing 210009, China
- Center for Stem Cell and Regenerative Medicine, Southeast University, Nanjing 210009, China
- Jiangsu Key Laboratory for Biomaterials and Devices, Southeast University, Nanjing 210096, China
- China Orthopedic Regenerative Medicine Group (CORMed), Hangzhou 310058, China
| | - Jialin Chen
- School of Medicine, Southeast University, Nanjing 210009, China
- Center for Stem Cell and Regenerative Medicine, Southeast University, Nanjing 210009, China
- Jiangsu Key Laboratory for Biomaterials and Devices, Southeast University, Nanjing 210096, China
- China Orthopedic Regenerative Medicine Group (CORMed), Hangzhou 310058, China
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Edouard P, Reurink G, Mackey AL, Lieber RL, Pizzari T, Järvinen TAH, Gronwald T, Hollander K. Traumatic muscle injury. Nat Rev Dis Primers 2023; 9:56. [PMID: 37857686 DOI: 10.1038/s41572-023-00469-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 09/22/2023] [Indexed: 10/21/2023]
Abstract
Traumatic muscle injury represents a collection of skeletal muscle pathologies caused by trauma to the muscle tissue and is defined as damage to the muscle tissue that can result in a functional deficit. Traumatic muscle injury can affect people across the lifespan and can result from high stresses and strains to skeletal muscle tissue, often due to muscle activation while the muscle is lengthening, resulting in indirect and non-contact muscle injuries (strains or ruptures), or from external impact, resulting in direct muscle injuries (contusion or laceration). At a microscopic level, muscle fibres can repair focal damage but must be completely regenerated after full myofibre necrosis. The diagnosis of muscle injury is based on patient history and physical examination. Imaging may be indicated to eliminate differential diagnoses. The management of muscle injury has changed within the past 5 years from initial rest, immobilization and (over)protection to early activation and progressive loading using an active approach. One challenge of muscle injury management is that numerous medical treatment options, such as medications and injections, are often used or proposed to try to accelerate muscle recovery despite very limited efficacy evidence. Another challenge is the prevention of muscle injury owing to the multifactorial and complex nature of this injury.
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Affiliation(s)
- Pascal Edouard
- Université Jean Monnet, Lyon 1, Université Savoie Mont-Blanc, Inter-university Laboratory of Human Movement Biology, Saint-Etienne, France.
- Department of Clinical and Exercise Physiology, Sports Medicine Unit, University Hospital of Saint-Etienne, Faculty of Medicine, Saint-Etienne, France.
| | - Gustaaf Reurink
- Department of Orthopedic Surgery and Sports Medicine, Academic Medical Center, University of Amsterdam, Amsterdam Movement Sciences, Amsterdam, Netherlands
- Academic Center for Evidence-based Sports Medicine (ACES), Academic Medical Center, Amsterdam, Netherlands
- The Sports Physicians Group, Onze Lieve Vrouwe Gasthuis, Amsterdam, Netherlands
| | - Abigail L Mackey
- Institute of Sports Medicine Copenhagen, Department of Orthopaedic Surgery M, Bispebjerg Hospital, Copenhagen, Denmark
- Center for Healthy Aging, Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Richard L Lieber
- Shirley Ryan AbilityLab, Chicago, IL, USA
- Departments of Physical Medicine and Rehabilitation and Biomedical Engineering, Northwestern University, Chicago, IL, USA
- Hines VA Medical Center, Maywood, IL, USA
| | - Tania Pizzari
- La Trobe Sport and Exercise Medicine Research Centre, La Trobe University, Melbourne, Victoria, Australia
| | - Tero A H Järvinen
- Tampere University and Tampere University Hospital, Tampere, Finland
| | - Thomas Gronwald
- Institute of Interdisciplinary Exercise Science and Sports Medicine, MSH Medical School Hamburg, Hamburg, Germany
| | - Karsten Hollander
- Institute of Interdisciplinary Exercise Science and Sports Medicine, MSH Medical School Hamburg, Hamburg, Germany
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Roberts MD, McCarthy JJ, Hornberger TA, Phillips SM, Mackey AL, Nader GA, Boppart MD, Kavazis AN, Reidy PT, Ogasawara R, Libardi CA, Ugrinowitsch C, Booth FW, Esser KA. Mechanisms of mechanical overload-induced skeletal muscle hypertrophy: current understanding and future directions. Physiol Rev 2023; 103:2679-2757. [PMID: 37382939 PMCID: PMC10625844 DOI: 10.1152/physrev.00039.2022] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Revised: 06/12/2023] [Accepted: 06/21/2023] [Indexed: 06/30/2023] Open
Abstract
Mechanisms underlying mechanical overload-induced skeletal muscle hypertrophy have been extensively researched since the landmark report by Morpurgo (1897) of "work-induced hypertrophy" in dogs that were treadmill trained. Much of the preclinical rodent and human resistance training research to date supports that involved mechanisms include enhanced mammalian/mechanistic target of rapamycin complex 1 (mTORC1) signaling, an expansion in translational capacity through ribosome biogenesis, increased satellite cell abundance and myonuclear accretion, and postexercise elevations in muscle protein synthesis rates. However, several lines of past and emerging evidence suggest that additional mechanisms that feed into or are independent of these processes are also involved. This review first provides a historical account of how mechanistic research into skeletal muscle hypertrophy has progressed. A comprehensive list of mechanisms associated with skeletal muscle hypertrophy is then outlined, and areas of disagreement involving these mechanisms are presented. Finally, future research directions involving many of the discussed mechanisms are proposed.
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Affiliation(s)
- Michael D Roberts
- School of Kinesiology, Auburn University, Auburn, Alabama, United States
| | - John J McCarthy
- Department of Physiology, College of Medicine, University of Kentucky, Lexington, Kentucky, United States
| | - Troy A Hornberger
- Department of Comparative Biosciences, University of Wisconsin-Madison, Madison, Wisconsin, United States
| | - Stuart M Phillips
- Department of Kinesiology, McMaster University, Hamilton, Ontario, Canada
| | - Abigail L Mackey
- Institute of Sports Medicine Copenhagen, Department of Orthopedic Surgery, Copenhagen University Hospital-Bispebjerg and Frederiksberg, and Department of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark
| | - Gustavo A Nader
- Department of Kinesiology and Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, Pennsylvania, United States
| | - Marni D Boppart
- Department of Kinesiology and Community Health, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States
| | - Andreas N Kavazis
- School of Kinesiology, Auburn University, Auburn, Alabama, United States
| | - Paul T Reidy
- Department of Kinesiology, Nutrition and Health, Miami University, Oxford, Ohio, United States
| | - Riki Ogasawara
- Healthy Food Science Research Group, Cellular and Molecular Biotechnology Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Japan
| | - Cleiton A Libardi
- MUSCULAB-Laboratory of Neuromuscular Adaptations to Resistance Training, Department of Physical Education, Federal University of São Carlos, São Carlos, Brazil
| | - Carlos Ugrinowitsch
- School of Physical Education and Sport, University of São Paulo, São Paulo, Brazil
| | - Frank W Booth
- Department of Biomedical Sciences, University of Missouri, Columbia, Missouri, United States
| | - Karyn A Esser
- Department of Physiology and Aging, College of Medicine, University of Florida, Gainesville, Florida, United States
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Negoita F, Addinsall AB, Hellberg K, Bringas CF, Hafen PS, Sermersheim TJ, Agerholm M, Lewis CTA, Ahwazi D, Ling NXY, Larsen JK, Deshmukh AS, Hossain MA, Oakhill JS, Ochala J, Brault JJ, Sankar U, Drewry DH, Scott JW, Witczak CA, Sakamoto K. CaMKK2 is not involved in contraction-stimulated AMPK activation and glucose uptake in skeletal muscle. Mol Metab 2023; 75:101761. [PMID: 37380024 PMCID: PMC10362367 DOI: 10.1016/j.molmet.2023.101761] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Revised: 06/21/2023] [Accepted: 06/22/2023] [Indexed: 06/30/2023] Open
Abstract
OBJECTIVE The AMP-activated protein kinase (AMPK) gets activated in response to energetic stress such as contractions and plays a vital role in regulating various metabolic processes such as insulin-independent glucose uptake in skeletal muscle. The main upstream kinase that activates AMPK through phosphorylation of α-AMPK Thr172 in skeletal muscle is LKB1, however some studies have suggested that Ca2+/calmodulin-dependent protein kinase kinase 2 (CaMKK2) acts as an alternative kinase to activate AMPK. We aimed to establish whether CaMKK2 is involved in activation of AMPK and promotion of glucose uptake following contractions in skeletal muscle. METHODS A recently developed CaMKK2 inhibitor (SGC-CAMKK2-1) alongside a structurally related but inactive compound (SGC-CAMKK2-1N), as well as CaMKK2 knock-out (KO) mice were used. In vitro kinase inhibition selectivity and efficacy assays, as well as cellular inhibition efficacy analyses of CaMKK inhibitors (STO-609 and SGC-CAMKK2-1) were performed. Phosphorylation and activity of AMPK following contractions (ex vivo) in mouse skeletal muscles treated with/without CaMKK inhibitors or isolated from wild-type (WT)/CaMKK2 KO mice were assessed. Camkk2 mRNA in mouse tissues was measured by qPCR. CaMKK2 protein expression was assessed by immunoblotting with or without prior enrichment of calmodulin-binding proteins from skeletal muscle extracts, as well as by mass spectrometry-based proteomics of mouse skeletal muscle and C2C12 myotubes. RESULTS STO-609 and SGC-CAMKK2-1 were equally potent and effective in inhibiting CaMKK2 in cell-free and cell-based assays, but SGC-CAMKK2-1 was much more selective. Contraction-stimulated phosphorylation and activation of AMPK were not affected with CaMKK inhibitors or in CaMKK2 null muscles. Contraction-stimulated glucose uptake was comparable between WT and CaMKK2 KO muscle. Both CaMKK inhibitors (STO-609 and SGC-CAMKK2-1) and the inactive compound (SGC-CAMKK2-1N) significantly inhibited contraction-stimulated glucose uptake. SGC-CAMKK2-1 also inhibited glucose uptake induced by a pharmacological AMPK activator or insulin. Relatively low levels of Camkk2 mRNA were detected in mouse skeletal muscle, but neither CaMKK2 protein nor its derived peptides were detectable in mouse skeletal muscle tissue. CONCLUSIONS We demonstrate that pharmacological inhibition or genetic loss of CaMKK2 does not affect contraction-stimulated AMPK phosphorylation and activation, as well as glucose uptake in skeletal muscle. Previously observed inhibitory effect of STO-609 on AMPK activity and glucose uptake is likely due to off-target effects. CaMKK2 protein is either absent from adult murine skeletal muscle or below the detection limit of currently available methods.
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Affiliation(s)
- Florentina Negoita
- Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen 2200, Denmark
| | - Alex B Addinsall
- Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen 2200, Denmark
| | - Kristina Hellberg
- Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen 2200, Denmark
| | - Conchita Fraguas Bringas
- Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen 2200, Denmark
| | - Paul S Hafen
- Department of Anatomy, Cell Biology & Physiology, and Indiana Center for Musculoskeletal Health, Indiana University School of Medicine, Indianapolis, IN 46202, USA; Indiana Center for Diabetes & Metabolic Diseases, Indiana University School of Medicine, Indianapolis, IN 46202, USA; Division of Science, Indiana University Purdue University Columbus, Columbus, IN 47203, USA
| | - Tyler J Sermersheim
- Department of Anatomy, Cell Biology & Physiology, and Indiana Center for Musculoskeletal Health, Indiana University School of Medicine, Indianapolis, IN 46202, USA; Indiana Center for Diabetes & Metabolic Diseases, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Marianne Agerholm
- Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen 2200, Denmark
| | - Christopher T A Lewis
- Department of Biomedical Sciences, University of Copenhagen, Copenhagen 2200, Denmark
| | - Danial Ahwazi
- Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen 2200, Denmark
| | - Naomi X Y Ling
- Metabolic Signalling, St. Vincent's Institute of Medical Research, Fitzroy, VIC 3065, Australia
| | - Jeppe K Larsen
- Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen 2200, Denmark
| | - Atul S Deshmukh
- Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen 2200, Denmark
| | - Mohammad A Hossain
- Structural Genomics Consortium, UNC Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Jonathan S Oakhill
- Metabolic Signalling, St. Vincent's Institute of Medical Research, Fitzroy, VIC 3065, Australia; Department of Medicine, University of Melbourne, Parkville, VIC 3010, Australia
| | - Julien Ochala
- Department of Biomedical Sciences, University of Copenhagen, Copenhagen 2200, Denmark
| | - Jeffrey J Brault
- Department of Anatomy, Cell Biology & Physiology, and Indiana Center for Musculoskeletal Health, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Uma Sankar
- Department of Anatomy, Cell Biology & Physiology, and Indiana Center for Musculoskeletal Health, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - David H Drewry
- Structural Genomics Consortium, UNC Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; Lineberger Comprehensive Cancer Center, Department of Medicine, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - John W Scott
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Parkville, Melbourne, VIC 3052, Australia; The Florey Institute of Neuroscience and Mental Health, Parkville, Melbourne, VIC 3052, Australia; St Vincent's Institute of Medical Research, Fitzroy, Melbourne, VIC 3065, Australia
| | - Carol A Witczak
- Department of Anatomy, Cell Biology & Physiology, and Indiana Center for Musculoskeletal Health, Indiana University School of Medicine, Indianapolis, IN 46202, USA; Indiana Center for Diabetes & Metabolic Diseases, Indiana University School of Medicine, Indianapolis, IN 46202, USA.
| | - Kei Sakamoto
- Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen 2200, Denmark; The Novo Nordisk Foundation Center for Genomic Mechanisms of Disease, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA.
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Dowling P, Gargan S, Zweyer M, Swandulla D, Ohlendieck K. Extracellular Matrix Proteomics: The mdx-4cv Mouse Diaphragm as a Surrogate for Studying Myofibrosis in Dystrophinopathy. Biomolecules 2023; 13:1108. [PMID: 37509144 PMCID: PMC10377647 DOI: 10.3390/biom13071108] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2023] [Revised: 07/06/2023] [Accepted: 07/10/2023] [Indexed: 07/30/2023] Open
Abstract
The progressive degeneration of the skeletal musculature in Duchenne muscular dystrophy is accompanied by reactive myofibrosis, fat substitution, and chronic inflammation. Fibrotic changes and reduced tissue elasticity correlate with the loss in motor function in this X-chromosomal disorder. Thus, although dystrophinopathies are due to primary abnormalities in the DMD gene causing the almost-complete absence of the cytoskeletal Dp427-M isoform of dystrophin in voluntary muscles, the excessive accumulation of extracellular matrix proteins presents a key histopathological hallmark of muscular dystrophy. Animal model research has been instrumental in the characterization of dystrophic muscles and has contributed to a better understanding of the complex pathogenesis of dystrophinopathies, the discovery of new disease biomarkers, and the testing of novel therapeutic strategies. In this article, we review how mass-spectrometry-based proteomics can be used to study changes in key components of the endomysium, perimysium, and epimysium, such as collagens, proteoglycans, matricellular proteins, and adhesion receptors. The mdx-4cv mouse diaphragm displays severe myofibrosis, making it an ideal model system for large-scale surveys of systematic alterations in the matrisome of dystrophic fibers. Novel biomarkers of myofibrosis can now be tested for their appropriateness in the preclinical and clinical setting as diagnostic, pharmacodynamic, prognostic, and/or therapeutic monitoring indicators.
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Affiliation(s)
- Paul Dowling
- Department of Biology, Maynooth University, National University of Ireland, W23 F2H6 Maynooth, Co. Kildare, Ireland
- Kathleen Lonsdale Institute for Human Health Research, Maynooth University, National University of Ireland, W23 F2H6 Maynooth, Co. Kildare, Ireland
| | - Stephen Gargan
- Department of Biology, Maynooth University, National University of Ireland, W23 F2H6 Maynooth, Co. Kildare, Ireland
- Kathleen Lonsdale Institute for Human Health Research, Maynooth University, National University of Ireland, W23 F2H6 Maynooth, Co. Kildare, Ireland
| | - Margit Zweyer
- Department of Neonatology and Paediatric Intensive Care, Children's Hospital, German Center for Neurodegenerative Diseases, University of Bonn, D53127 Bonn, Germany
| | - Dieter Swandulla
- Institute of Physiology, Medical Faculty, University of Bonn, D53115 Bonn, Germany
| | - Kay Ohlendieck
- Department of Biology, Maynooth University, National University of Ireland, W23 F2H6 Maynooth, Co. Kildare, Ireland
- Kathleen Lonsdale Institute for Human Health Research, Maynooth University, National University of Ireland, W23 F2H6 Maynooth, Co. Kildare, Ireland
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9
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Casey JG, Kim ES, Joseph R, Li F, Granzier H, Gupta VA. NRAP reduction rescues sarcomere defects in nebulin-related nemaline myopathy. Hum Mol Genet 2023; 32:1711-1721. [PMID: 36661122 PMCID: PMC10162428 DOI: 10.1093/hmg/ddad011] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Revised: 11/18/2022] [Accepted: 01/17/2023] [Indexed: 01/21/2023] Open
Abstract
Nemaline myopathy (NM) is a rare neuromuscular disorder associated with congenital or childhood-onset of skeletal muscle weakness and hypotonia, which results in limited motor function. NM is a genetic disorder and mutations in 12 genes are known to contribute to autosomal dominant or recessive forms of the disease. Recessive mutations in nebulin (NEB) are the most common cause of NM affecting about 50% of patients. Because of the large size of the NEB gene and lack of mutational hot spots, developing therapies that can benefit a wide group of patients is challenging. Although there are several promising therapies under investigation, there is no cure for NM. Therefore, targeting disease modifiers that can stabilize or improve skeletal muscle function may represent alternative therapeutic strategies. Our studies have identified Nrap upregulation in nebulin deficiency that contributes to structural and functional deficits in NM. We show that genetic ablation of nrap in nebulin deficiency restored sarcomeric disorganization, reduced protein aggregates and improved skeletal muscle function in zebrafish. Our findings suggest that Nrap is a disease modifier that affects skeletal muscle structure and function in NM; thus, therapeutic targeting of Nrap in nebulin-related NM and related diseases may be beneficial for patients.
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Affiliation(s)
- Jennifer G Casey
- Division of Genetics, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Euri S Kim
- Division of Genetics, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Remi Joseph
- Division of Genetics, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Frank Li
- Department of Cellular and Molecular Medicine, University of Arizona, Tucson, AZ 85724, USA
| | - Henk Granzier
- Department of Cellular and Molecular Medicine, University of Arizona, Tucson, AZ 85724, USA
| | - Vandana A Gupta
- Division of Genetics, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA 02115, USA
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10
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Xu R, Wu M, Wang Y, Li C, Zeng L, Wang Y, Xiao M, Chen X, Geng S, Lai P, Du X, Weng J. Mesenchymal stem cells reversibly de-differentiate myofibroblasts to fibroblast-like cells by inhibiting the TGF-β-SMAD2/3 pathway. Mol Med 2023; 29:59. [PMID: 37098464 PMCID: PMC10131436 DOI: 10.1186/s10020-023-00630-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Accepted: 03/07/2023] [Indexed: 04/27/2023] Open
Abstract
BACKGROUND Myofibroblasts (MFB), one of the major effectors of pathologic fibrosis, mainly derived from the activation of fibroblast to myofibroblast transition (FMT). Although MFBs were historically considered terminally differentiated cells, their potential for de-differentiation was recently recognized and implied with therapeutic value in treating fibrotic diseases, for instance, idiopathic pulmonary fibrosis (IPF) and post allogeneic hematopoietic stem cell transplantation bronchiolitis obliterans (BO). During the past decade, several methods were reported to block or reverse MFB differentiation, among which mesenchymal stem cells (MSC) have demonstrated potential but undetermined therapeutic values. However, the MSC-mediated regulation of FMT and underlying mechanisms remained largely undefined. METHOD By identifying TGF-β1 hypertension as the pivotal landmark during the pro-fibrotic FMT, TGF-β1-induced MFB and MSC co-culture models were established and utilized to investigate regulations by MSC on FMT in vitro. Methods including RNA sequencing (RNA-seq), Western blot, qPCR and flow cytometry were used. RESULT Our data revealed that TGF-β1 readily induced invasive signatures identified in fibrotic tissues and initiated MFB differentiation in normal FB. MSC reversibly de-differentiated MFB into a group of FB-like cells by selectively inhibiting the TGF-β-SMAD2/3 signaling. Importantly, these proliferation-boosted FB-like cells remained sensitive to TGF-β1 and could be re-induced into MFB. CONCLUSION Our findings highlighted the reversibility of MSC-mediated de-differentiation of MFB through TGF-β-SMAD2/3 signaling, which may explain MSC's inconsistent clinical efficacies in treating BO and other fibrotic diseases. These de-differentiated FB-like cells are still sensitive to TGF-β1 and may further deteriorate MFB phenotypes unless the pro-fibrotic microenvironment is corrected.
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Affiliation(s)
- Ruohao Xu
- Department of Hematology, Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, Guangzhou, Guangdong, 510080, People's Republic of China
| | - Miao Wu
- Department of Hematology, Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, Guangzhou, Guangdong, 510080, People's Republic of China
| | - Yawen Wang
- Department of Hematology, Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, Guangzhou, Guangdong, 510080, People's Republic of China
| | - Chao Li
- Department of Hematology, Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, Guangzhou, Guangdong, 510080, People's Republic of China
| | - Lingji Zeng
- Department of Hematology, Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, Guangzhou, Guangdong, 510080, People's Republic of China
| | - Yulian Wang
- Department of Hematology, Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, Guangzhou, Guangdong, 510080, People's Republic of China
| | - Maozhi Xiao
- Department of Hematology, Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, Guangzhou, Guangdong, 510080, People's Republic of China
| | - Xiaomei Chen
- Department of Hematology, Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, Guangzhou, Guangdong, 510080, People's Republic of China
| | - Suxia Geng
- Department of Hematology, Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, Guangzhou, Guangdong, 510080, People's Republic of China
| | - Peilong Lai
- Department of Hematology, Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, Guangzhou, Guangdong, 510080, People's Republic of China
| | - Xin Du
- Department of Hematology, Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, Guangzhou, Guangdong, 510080, People's Republic of China.
| | - Jianyu Weng
- Department of Hematology, Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, Guangzhou, Guangdong, 510080, People's Republic of China.
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11
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Lipp SN, Jacobson KR, Colling HA, Tuttle TG, Miles DT, McCreery KP, Calve S. Mechanical loading is required for initiation of extracellular matrix deposition at the developing murine myotendinous junction. Matrix Biol 2023; 116:28-48. [PMID: 36709857 PMCID: PMC10218368 DOI: 10.1016/j.matbio.2023.01.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2022] [Revised: 01/17/2023] [Accepted: 01/24/2023] [Indexed: 01/27/2023]
Abstract
The myotendinous junction (MTJ) contributes to the generation of motion by connecting muscle to tendon. At the adult MTJ, a specialized extracellular matrix (ECM) is thought to contribute to the mechanical integrity of the muscle-tendon interface, but the factors that influence MTJ formation during mammalian development are unclear. Here, we combined 3D imaging and proteomics with murine models in which muscle contractility and patterning are disrupted to resolve morphological and compositional changes in the ECM during MTJ development. We found that MTJ-specific ECM deposition can be initiated via static loading due to growth; however, it required cyclic loading to develop a mature morphology. Furthermore, the MTJ can mature without the tendon terminating into cartilage. Based on these results, we describe a model wherein MTJ development depends on mechanical loading but not insertion into an enthesis.
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Affiliation(s)
- Sarah N Lipp
- Weldon School of Biomedical Engineering, Purdue University, 206 South Martin Jischke Drive, West Lafayette, IN 47907, United States; The Indiana University Medical Scientist/Engineer Training Program, Indianapolis, IN 46202, United States
| | - Kathryn R Jacobson
- Purdue University Interdisciplinary Life Science Program, 155 S. Grant Street, West Lafayette, IN 47907, United States
| | - Haley A Colling
- Department of Integrative Physiology, University of Colorado Boulder, 354 UCB, Boulder CO, 80309, United States
| | - Tyler G Tuttle
- Paul M. Rady Department of Mechanical Engineering, University of Colorado Boulder, 1111 Engineering Dr, Boulder, CO 80309, United States
| | - Dalton T Miles
- Chemical and Biological Engineering, University of Colorado Boulder, 596 UCB, CO 80309, United States
| | - Kaitlin P McCreery
- Paul M. Rady Department of Mechanical Engineering, University of Colorado Boulder, 1111 Engineering Dr, Boulder, CO 80309, United States
| | - Sarah Calve
- Weldon School of Biomedical Engineering, Purdue University, 206 South Martin Jischke Drive, West Lafayette, IN 47907, United States; Purdue University Interdisciplinary Life Science Program, 155 S. Grant Street, West Lafayette, IN 47907, United States; Paul M. Rady Department of Mechanical Engineering, University of Colorado Boulder, 1111 Engineering Dr, Boulder, CO 80309, United States.
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