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Cai Q, Sahu R, Ueberschlag-Pitiot V, Souali-Crespo S, Charvet C, Silem I, Cottard F, Ye T, Taleb F, Metzger E, Schuele R, Billas IML, Laverny G, Metzger D, Duteil D. LSD1 inhibition circumvents glucocorticoid-induced muscle wasting of male mice. Nat Commun 2024; 15:3563. [PMID: 38670969 PMCID: PMC11053113 DOI: 10.1038/s41467-024-47846-9] [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: 06/09/2023] [Accepted: 04/15/2024] [Indexed: 04/28/2024] Open
Abstract
Synthetic glucocorticoids (GC), such as dexamethasone, are extensively used to treat chronic inflammation and autoimmune disorders. However, long-term treatments are limited by various side effects, including muscle atrophy. GC activities are mediated by the glucocorticoid receptor (GR), that regulates target gene expression in various tissues in association with cell-specific co-regulators. Here we show that GR and the lysine-specific demethylase 1 (LSD1) interact in myofibers of male mice, and that LSD1 connects GR-bound enhancers with NRF1-associated promoters to stimulate target gene expression. In addition, we unravel that LSD1 demethylase activity is required for triggering starvation- and dexamethasone-induced skeletal muscle proteolysis in collaboration with GR. Importantly, inhibition of LSD1 circumvents muscle wasting induced by pharmacological levels of dexamethasone, without affecting their anti-inflammatory activities. Thus, our findings provide mechanistic insights into the muscle-specific GC activities, and highlight the therapeutic potential of targeting GR co-regulators to limit corticotherapy-induced side effects.
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Affiliation(s)
- Qingshuang Cai
- Université de Strasbourg, CNRS, Inserm, IGBMC UMR 7104- UMR-S 1258, F-67400, Illkirch, France
| | - Rajesh Sahu
- Université de Strasbourg, CNRS, Inserm, IGBMC UMR 7104- UMR-S 1258, F-67400, Illkirch, France
| | | | - Sirine Souali-Crespo
- Université de Strasbourg, CNRS, Inserm, IGBMC UMR 7104- UMR-S 1258, F-67400, Illkirch, France
| | - Céline Charvet
- Université de Strasbourg, CNRS, Inserm, IGBMC UMR 7104- UMR-S 1258, F-67400, Illkirch, France
| | - Ilyes Silem
- Université de Strasbourg, CNRS, Inserm, IGBMC UMR 7104- UMR-S 1258, F-67400, Illkirch, France
| | - Félicie Cottard
- Université de Strasbourg, CNRS, Inserm, IGBMC UMR 7104- UMR-S 1258, F-67400, Illkirch, France
| | - Tao Ye
- Université de Strasbourg, CNRS, Inserm, IGBMC UMR 7104- UMR-S 1258, F-67400, Illkirch, France
| | - Fatima Taleb
- Université de Strasbourg, CNRS, Inserm, IGBMC UMR 7104- UMR-S 1258, F-67400, Illkirch, France
| | - Eric Metzger
- Klinik für Urologie und Zentrale Klinische Forschung, Klinikum der Albert-Ludwigs-Universität Freiburg, D-79106, Freiburg, Germany
| | - Roland Schuele
- Klinik für Urologie und Zentrale Klinische Forschung, Klinikum der Albert-Ludwigs-Universität Freiburg, D-79106, Freiburg, Germany
| | - Isabelle M L Billas
- Université de Strasbourg, CNRS, Inserm, IGBMC UMR 7104- UMR-S 1258, F-67400, Illkirch, France
| | - Gilles Laverny
- Université de Strasbourg, CNRS, Inserm, IGBMC UMR 7104- UMR-S 1258, F-67400, Illkirch, France
| | - Daniel Metzger
- Université de Strasbourg, CNRS, Inserm, IGBMC UMR 7104- UMR-S 1258, F-67400, Illkirch, France
| | - Delphine Duteil
- Université de Strasbourg, CNRS, Inserm, IGBMC UMR 7104- UMR-S 1258, F-67400, Illkirch, France.
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2
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Vidal J, Fernandez EA, Wohlwend M, Laurila P, Lopez‐Mejia A, Ochala J, Lobrinus AJ, Kayser B, Lopez‐Mejia IC, Place N, Zanou N. Ryanodine receptor type 1 content decrease-induced endoplasmic reticulum stress is a hallmark of myopathies. J Cachexia Sarcopenia Muscle 2023; 14:2882-2897. [PMID: 37964752 PMCID: PMC10751419 DOI: 10.1002/jcsm.13349] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Revised: 07/24/2023] [Accepted: 09/11/2023] [Indexed: 11/16/2023] Open
Abstract
BACKGROUND Decreased ryanodine receptor type 1 (RyR1) protein levels are a well-described feature of recessive RYR1-related myopathies. The aim of the present study was twofold: (1) to determine whether RyR1 content is also decreased in other myopathies and (2) to investigate the mechanisms by which decreased RyR1 protein triggers muscular disorders. METHODS We used publicly available datasets, muscles from human inflammatory and mitochondrial myopathies, an inducible muscle-specific RYR1 recessive mouse model and RyR1 knockdown in C2C12 muscle cells to measure RyR1 content and endoplasmic reticulum (ER) stress markers. Proteomics, lipidomics, molecular biology and transmission electron microscopy approaches were used to decipher the alterations associated with the reduction of RyR1 protein levels. RESULTS RYR1 transcripts were reduced in muscle samples of patients suffering from necrotizing myopathy (P = 0.026), inclusion body myopathy (P = 0.003), polymyositis (P < 0.001) and juvenile dermatomyositis (P < 0.001) and in muscle samples of myotonic dystrophy type 2 (P < 0.001), presymptomatic (P < 0.001) and symptomatic (P < 0.001) Duchenne muscular dystrophy, Becker muscular dystrophy (P = 0.004) and limb-girdle muscular dystrophy type 2A (P = 0.004). RyR1 protein content was also significantly decreased in inflammatory myopathy (-75%, P < 0.001) and mitochondrial myopathy (-71%, P < 0.001) muscles. Proteomics data showed that depletion of RyR1 protein in C2C12 myoblasts leads to myotubes recapitulating the common molecular alterations observed in myopathies. Mechanistically, RyR1 protein depletion reduces ER-mitochondria contact length (-26%, P < 0.001), Ca2+ transfer to mitochondria (-48%, P = 0.002) and the mitophagy gene Parkinson protein 2 transcripts (P = 0.037) and induces mitochondrial accumulation (+99%, P = 0.005) and dysfunction (P < 0.001). This was associated to the accumulation of deleterious sphingolipid species. Our data showed increased levels of the ER stress marker chaperone-binding protein/glucose regulated protein 78, GRP78-Bip, in RyR1 knockdown myotubes (+45%, P = 0.046), in mouse RyR1 recessive muscles (+58%, P = 0.001) and in human inflammatory (+96%, P = 0.006) and mitochondrial (+64%, P = 0.049) myopathy muscles. This was accompanied by increased protein levels of the pro-apoptotic protein CCAAT-enhancer-binding protein homologous protein, CHOP-DDIT3, in RyR1 knockdown myotubes (+27%, P < 0.001), mouse RyR1 recessive muscles (+63%, P = 0.009), human inflammatory (+50%, P = 0.038) and mitochondrial (+51%, P = 0.035) myopathy muscles. In publicly available datasets, the decrease in RYR1 content in myopathies was also associated to increased ER stress markers and RYR1 transcript levels are inversely correlated with ER stress markers in the control population. CONCLUSIONS Decreased RyR1 is commonly observed in myopathies and associated to ER stress in vitro, in mouse muscle and in human myopathy muscles, suggesting a potent role of RyR1 depletion-induced ER stress in the pathogenesis of myopathies.
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Affiliation(s)
- Jeremy Vidal
- Institute of Sport Sciences and Department of Biomedical SciencesUniversity of LausanneLausanneSwitzerland
| | - Eric A. Fernandez
- Center for Integrative GenomicsUniversity of LausanneLausanneSwitzerland
| | - Martin Wohlwend
- Computer Science and Artificial Intelligence LaboratoryMassachusetts Institute of TechnologyCambridgeMassachusettsUSA
| | | | - Andrea Lopez‐Mejia
- Center for Integrative GenomicsUniversity of LausanneLausanneSwitzerland
| | - Julien Ochala
- Department of Biomedical SciencesUniversity of CopenhagenCopenhagenDenmark
| | - Alexander J. Lobrinus
- Institute of PathologyLausanne University Hospital (CHUV)LausanneSwitzerland
- Department of Clinical PathologyUniversity Hospital GenevaGenevaSwitzerland
| | - Bengt Kayser
- Institute of Sport Sciences and Department of Biomedical SciencesUniversity of LausanneLausanneSwitzerland
| | | | - Nicolas Place
- Institute of Sport Sciences and Department of Biomedical SciencesUniversity of LausanneLausanneSwitzerland
| | - Nadège Zanou
- Institute of Sport Sciences and Department of Biomedical SciencesUniversity of LausanneLausanneSwitzerland
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3
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Ninfali C, Cortés M, Martínez-Campanario MC, Domínguez V, Han L, Tobías E, Esteve-Codina A, Enrich C, Pintado B, Garrabou G, Postigo A. The adaptive antioxidant response during fasting-induced muscle atrophy is oppositely regulated by ZEB1 and ZEB2. Proc Natl Acad Sci U S A 2023; 120:e2301120120. [PMID: 37948583 PMCID: PMC10655555 DOI: 10.1073/pnas.2301120120] [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: 01/20/2023] [Accepted: 09/26/2023] [Indexed: 11/12/2023] Open
Abstract
Reactive oxygen species (ROS) serve important homeostatic functions but must be constantly neutralized by an adaptive antioxidant response to prevent supraphysiological levels of ROS from causing oxidative damage to cellular components. Here, we report that the cellular plasticity transcription factors ZEB1 and ZEB2 modulate in opposing directions the adaptive antioxidant response to fasting in skeletal muscle. Using transgenic mice in which Zeb1 or Zeb2 were specifically deleted in skeletal myofibers, we show that in fasted mice, the deletion of Zeb1, but not Zeb2, increased ROS production and that the adaptive antioxidant response to fasting essentially requires ZEB1 and is inhibited by ZEB2. ZEB1 expression increased in fasted muscles and protected them from atrophy; conversely, ZEB2 expression in muscles decreased during fasting and exacerbated muscle atrophy. In fasted muscles, ZEB1 reduces mitochondrial damage and increases mitochondrial respiratory activity; meanwhile, ZEB2 did the opposite. Treatment of fasting mice with Zeb1-deficient myofibers with the antioxidant triterpenoid 1[2-cyano-3,12-dioxool-eana-1,9(11)-dien-28-oyl] trifluoro-ethylamide (CDDO-TFEA) completely reversed their altered phenotype to that observed in fasted control mice. These results set ZEB factors as potential therapeutic targets to modulate the adaptive antioxidant response in physiopathological conditions and diseases caused by redox imbalance.
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Affiliation(s)
- Chiara Ninfali
- Group of Gene Regulation in Stem Cells, Cell Plasticity, Differentiation, and Cancer, Institute of Biomedical Research August Pi Sunyer (IDIBAPS), Barcelona08036, Spain
| | - Marlies Cortés
- Group of Gene Regulation in Stem Cells, Cell Plasticity, Differentiation, and Cancer, Institute of Biomedical Research August Pi Sunyer (IDIBAPS), Barcelona08036, Spain
| | - M. C. Martínez-Campanario
- Group of Gene Regulation in Stem Cells, Cell Plasticity, Differentiation, and Cancer, Institute of Biomedical Research August Pi Sunyer (IDIBAPS), Barcelona08036, Spain
| | - Verónica Domínguez
- National Center of Biotechnology (CSIC-CNB) and Center for Molecular Biology Severo Ochoa (CSIC-CBMSO), Transgenesis Facility, High Research Council (CSIC) and Autonomous University of Madrid, Cantoblanco, Madrid28049, Spain
| | - Lu Han
- Group of Gene Regulation in Stem Cells, Cell Plasticity, Differentiation, and Cancer, Institute of Biomedical Research August Pi Sunyer (IDIBAPS), Barcelona08036, Spain
| | - Ester Tobías
- Group of Muscle Research and Mitochondrial Function, Institute of Biomedical Research August Pi Sunyer (IDIBAPS), University of Barcelona School of Medicine, Hospital Clínic of Barcelona, and Rare Diseases Networking Biomedical Research Center (CIBERer), Barcelona08036, Spain
| | | | - Carlos Enrich
- Department of Biomedicine, University of Barcelona School of Medicine, and Institute of Biomedical Research August Pi Sunyer (IDIBAPS), Barcelona08036, Spain
| | - Belén Pintado
- National Center of Biotechnology (CSIC-CNB) and Center for Molecular Biology Severo Ochoa (CSIC-CBMSO), Transgenesis Facility, High Research Council (CSIC) and Autonomous University of Madrid, Cantoblanco, Madrid28049, Spain
| | - Gloria Garrabou
- Group of Muscle Research and Mitochondrial Function, Institute of Biomedical Research August Pi Sunyer (IDIBAPS), University of Barcelona School of Medicine, Hospital Clínic of Barcelona, and Rare Diseases Networking Biomedical Research Center (CIBERer), Barcelona08036, Spain
| | - Antonio Postigo
- Group of Gene Regulation in Stem Cells, Cell Plasticity, Differentiation, and Cancer, Institute of Biomedical Research August Pi Sunyer (IDIBAPS), Barcelona08036, Spain
- Molecular Targets Program, Department of Medicine, James Graham Brown Cancer Center, Louisville, KY40202
- Catalan Institution for Research and Advanced Studies (ICREA), Barcelona08010, Spain
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4
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Lancaster MS, Kim B, Doud EH, Tate MD, Sharify AD, Gao H, Chen D, Simpson E, Gillespie P, Chu X, Miller MJ, Wang Y, Liu Y, Mosley AL, Kim J, Graham BH. Loss of succinyl-CoA synthetase in mouse forebrain results in hypersuccinylation with perturbed neuronal transcription and metabolism. Cell Rep 2023; 42:113241. [PMID: 37819759 PMCID: PMC10683835 DOI: 10.1016/j.celrep.2023.113241] [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: 08/08/2022] [Revised: 08/24/2023] [Accepted: 09/25/2023] [Indexed: 10/13/2023] Open
Abstract
Lysine succinylation is a subtype of protein acylation associated with metabolic regulation of succinyl-CoA in the tricarboxylic acid cycle. Deficiency of succinyl-CoA synthetase (SCS), the tricarboxylic acid cycle enzyme catalyzing the interconversion of succinyl-CoA to succinate, results in mitochondrial encephalomyopathy in humans. This report presents a conditional forebrain-specific knockout (KO) mouse model of Sucla2, the gene encoding the ATP-specific beta isoform of SCS, resulting in postnatal deficiency of the entire SCS complex. Results demonstrate that accumulation of succinyl-CoA in the absence of SCS leads to hypersuccinylation within the murine cerebral cortex. Specifically, increased succinylation is associated with functionally significant reduced activity of respiratory chain complex I and widescale alterations in chromatin landscape and gene expression. Integrative analysis of the transcriptomic data also reveals perturbations in regulatory networks of neuronal transcription in the KO forebrain. Together, these findings provide evidence that protein succinylation plays a significant role in the pathogenesis of SCS deficiency.
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Affiliation(s)
- Makayla S Lancaster
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Byungwook Kim
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN 46202, USA; Stark Neuroscience Research Institute, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Emma H Doud
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Mason D Tate
- Stark Neuroscience Research Institute, Indiana University School of Medicine, Indianapolis, IN 46202, USA; Medical Neuroscience Graduate Program, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Ahmad D Sharify
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN 46202, USA; Stark Neuroscience Research Institute, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Hongyu Gao
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN 46202, USA; Center for Computational Biology and Bioinformatics, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Duojiao Chen
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Ed Simpson
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Patrick Gillespie
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Xiaona Chu
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Marcus J Miller
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Yue Wang
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Yunlong Liu
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN 46202, USA; Center for Computational Biology and Bioinformatics, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Amber L Mosley
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Jungsu Kim
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN 46202, USA; Stark Neuroscience Research Institute, Indiana University School of Medicine, Indianapolis, IN 46202, USA; Medical Neuroscience Graduate Program, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Brett H Graham
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN 46202, USA.
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5
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Leduc-Gaudet JP, Miguez K, Cefis M, Faitg J, Moamer A, Chaffer TJ, Reynaud O, Broering FE, Shams A, Mayaki D, Huck L, Sandri M, Gouspillou G, Hussain SN. Autophagy ablation in skeletal muscles worsens sepsis-induced muscle wasting, impairs whole-body metabolism, and decreases survival. iScience 2023; 26:107475. [PMID: 37588163 PMCID: PMC10425945 DOI: 10.1016/j.isci.2023.107475] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Revised: 05/18/2023] [Accepted: 07/21/2023] [Indexed: 08/18/2023] Open
Abstract
Septic patients frequently develop skeletal muscle wasting and weakness, resulting in severe clinical consequences and adverse outcomes. Sepsis triggers sustained induction of autophagy, a key cellular degradative pathway, in skeletal muscles. However, the impact of enhanced autophagy on sepsis-induced muscle dysfunction remains unclear. Using an inducible and muscle-specific Atg7 knockout mouse model (Atg7iSkM-KO), we investigated the functional importance of skeletal muscle autophagy in sepsis using the cecal ligation and puncture model. Atg7iSkM-KO mice exhibited a more severe phenotype in response to sepsis, marked by severe muscle wasting, hypoglycemia, higher ketone levels, and a decreased in survival as compared to mice with intact Atg7. Sepsis and Atg7 deletion resulted in the accumulation of mitochondrial dysfunction, although sepsis did not further worsen mitochondrial dysfunction in Atg7iSkM-KO mice. Overall, our study demonstrates that autophagy inactivation in skeletal muscles triggers significant worsening of sepsis-induced muscle and metabolic dysfunctions and negatively impacts survival.
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Affiliation(s)
- Jean-Philippe Leduc-Gaudet
- Research Group in Cellular Signaling, Department of Medical Biology, Université du Québec À Trois-Rivières, Trois-Rivières, QC G9A 5H7, Canada
- Department of Critical Care and Translational Research in Respiratory Diseases Program, Research Institute of the McGill University Health Centre (MUHC), Montréal, QC H3H 2R9, Canada
- Meakins-Christie Laboratories, Department of Medicine, Faculty of Medicine, McGill University, Montréal, QC H4A 3J1, Canada
- Département des sciences de l’activité physique, Faculté des sciences, Université du Québec à Montréal (UQAM), Montréal, QC H2X 1Y4, Canada
| | - Kayla Miguez
- Department of Critical Care and Translational Research in Respiratory Diseases Program, Research Institute of the McGill University Health Centre (MUHC), Montréal, QC H3H 2R9, Canada
- Meakins-Christie Laboratories, Department of Medicine, Faculty of Medicine, McGill University, Montréal, QC H4A 3J1, Canada
| | - Marina Cefis
- Meakins-Christie Laboratories, Department of Medicine, Faculty of Medicine, McGill University, Montréal, QC H4A 3J1, Canada
- Département des sciences de l’activité physique, Faculté des sciences, Université du Québec à Montréal (UQAM), Montréal, QC H2X 1Y4, Canada
| | - Julie Faitg
- Département des sciences de l’activité physique, Faculté des sciences, Université du Québec à Montréal (UQAM), Montréal, QC H2X 1Y4, Canada
- Amazentis SA, EPFL Innovation Park, 1015 Lausanne, Switzerland
| | - Alaa Moamer
- Meakins-Christie Laboratories, Department of Medicine, Faculty of Medicine, McGill University, Montréal, QC H4A 3J1, Canada
| | - Tomer Jordi Chaffer
- Department of Critical Care and Translational Research in Respiratory Diseases Program, Research Institute of the McGill University Health Centre (MUHC), Montréal, QC H3H 2R9, Canada
- Meakins-Christie Laboratories, Department of Medicine, Faculty of Medicine, McGill University, Montréal, QC H4A 3J1, Canada
| | - Olivier Reynaud
- Département des sciences de l’activité physique, Faculté des sciences, Université du Québec à Montréal (UQAM), Montréal, QC H2X 1Y4, Canada
| | - Felipe E. Broering
- Department of Critical Care and Translational Research in Respiratory Diseases Program, Research Institute of the McGill University Health Centre (MUHC), Montréal, QC H3H 2R9, Canada
- Meakins-Christie Laboratories, Department of Medicine, Faculty of Medicine, McGill University, Montréal, QC H4A 3J1, Canada
| | - Anwar Shams
- Department of Pharmacology, Faculty of Medicine, Taif University, P.O.BOX 11099, Taif 21944, Saudi Arabia
| | - Dominique Mayaki
- Department of Critical Care and Translational Research in Respiratory Diseases Program, Research Institute of the McGill University Health Centre (MUHC), Montréal, QC H3H 2R9, Canada
- Meakins-Christie Laboratories, Department of Medicine, Faculty of Medicine, McGill University, Montréal, QC H4A 3J1, Canada
| | - Laurent Huck
- Department of Critical Care and Translational Research in Respiratory Diseases Program, Research Institute of the McGill University Health Centre (MUHC), Montréal, QC H3H 2R9, Canada
- Meakins-Christie Laboratories, Department of Medicine, Faculty of Medicine, McGill University, Montréal, QC H4A 3J1, Canada
| | - Marco Sandri
- Meakins-Christie Laboratories, Department of Medicine, Faculty of Medicine, McGill University, Montréal, QC H4A 3J1, Canada
- Veneto Institute of Molecular Medicine (VIMM) and Department of Biomedical Science, Università di Padova, 35129 Padova, Italy
| | - Gilles Gouspillou
- Meakins-Christie Laboratories, Department of Medicine, Faculty of Medicine, McGill University, Montréal, QC H4A 3J1, Canada
- Département des sciences de l’activité physique, Faculté des sciences, Université du Québec à Montréal (UQAM), Montréal, QC H2X 1Y4, Canada
| | - Sabah N.A. Hussain
- Department of Critical Care and Translational Research in Respiratory Diseases Program, Research Institute of the McGill University Health Centre (MUHC), Montréal, QC H3H 2R9, Canada
- Meakins-Christie Laboratories, Department of Medicine, Faculty of Medicine, McGill University, Montréal, QC H4A 3J1, Canada
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Zhang Y, Ramirez-Martinez A, Chen K, McAnally JR, Cai C, Durbacz MZ, Chemello F, Wang Z, Xu L, Bassel-Duby R, Liu N, Olson EN. Net39 protects muscle nuclei from mechanical stress during the pathogenesis of Emery-Dreifuss muscular dystrophy. J Clin Invest 2023; 133:e163333. [PMID: 37395273 PMCID: PMC10313361 DOI: 10.1172/jci163333] [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: 07/06/2022] [Accepted: 05/16/2023] [Indexed: 07/04/2023] Open
Abstract
Mutations in genes encoding nuclear envelope proteins lead to diseases known as nuclear envelopathies, characterized by skeletal muscle and heart abnormalities, such as Emery-Dreifuss muscular dystrophy (EDMD). The tissue-specific role of the nuclear envelope in the etiology of these diseases has not been extensively explored. We previously showed that global deletion of the muscle-specific nuclear envelope protein NET39 in mice leads to neonatal lethality due to skeletal muscle dysfunction. To study the potential role of the Net39 gene in adulthood, we generated a muscle-specific conditional knockout (cKO) of Net39 in mice. cKO mice recapitulated key skeletal muscle features of EDMD, including muscle wasting, impaired muscle contractility, abnormal myonuclear morphology, and DNA damage. The loss of Net39 rendered myoblasts hypersensitive to mechanical stretch, resulting in stretch-induced DNA damage. Net39 was downregulated in a mouse model of congenital myopathy, and restoration of Net39 expression through AAV gene delivery extended life span and ameliorated muscle abnormalities. These findings establish NET39 as a direct contributor to the pathogenesis of EDMD that acts by protecting against mechanical stress and DNA damage.
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Affiliation(s)
- Yichi Zhang
- Department of Molecular Biology
- Hamon Center for Regenerative Science and Medicine
- Senator Paul D. Wellstone Muscular Dystrophy Cooperative Research Center
| | - Andres Ramirez-Martinez
- Department of Molecular Biology
- Hamon Center for Regenerative Science and Medicine
- Senator Paul D. Wellstone Muscular Dystrophy Cooperative Research Center
| | - Kenian Chen
- Quantitative Biomedical Research Center, Peter O’Donnell Jr. School of Public Health, and
| | - John R. McAnally
- Department of Molecular Biology
- Hamon Center for Regenerative Science and Medicine
- Senator Paul D. Wellstone Muscular Dystrophy Cooperative Research Center
| | - Chunyu Cai
- Department of Pathology, University of Texas (UT) Southwestern Medical Center, Dallas, Texas, USA
| | - Mateusz Z. Durbacz
- Department of Molecular Biology
- Hamon Center for Regenerative Science and Medicine
- Senator Paul D. Wellstone Muscular Dystrophy Cooperative Research Center
| | - Francesco Chemello
- Department of Molecular Biology
- Hamon Center for Regenerative Science and Medicine
- Senator Paul D. Wellstone Muscular Dystrophy Cooperative Research Center
| | - Zhaoning Wang
- Department of Molecular Biology
- Hamon Center for Regenerative Science and Medicine
- Senator Paul D. Wellstone Muscular Dystrophy Cooperative Research Center
| | - Lin Xu
- Quantitative Biomedical Research Center, Peter O’Donnell Jr. School of Public Health, and
| | - Rhonda Bassel-Duby
- Department of Molecular Biology
- Hamon Center for Regenerative Science and Medicine
- Senator Paul D. Wellstone Muscular Dystrophy Cooperative Research Center
| | - Ning Liu
- Department of Molecular Biology
- Hamon Center for Regenerative Science and Medicine
- Senator Paul D. Wellstone Muscular Dystrophy Cooperative Research Center
| | - Eric N. Olson
- Department of Molecular Biology
- Hamon Center for Regenerative Science and Medicine
- Senator Paul D. Wellstone Muscular Dystrophy Cooperative Research Center
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7
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Witcher PC, Sun C, Millay DP. Expression of Myomaker and Myomerger in myofibers causes muscle pathology. Skelet Muscle 2023; 13:8. [PMID: 37127758 PMCID: PMC10150476 DOI: 10.1186/s13395-023-00317-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Accepted: 04/17/2023] [Indexed: 05/03/2023] Open
Abstract
BACKGROUND Skeletal muscle development and regeneration depend on cellular fusion of myogenic progenitors to generate multinucleated myofibers. These progenitors utilize two muscle-specific fusogens, Myomaker and Myomerger, which function by remodeling cell membranes to fuse to each other or to existing myofibers. Myomaker and Myomerger expression is restricted to differentiating progenitor cells as they are not detected in adult myofibers. However, Myomaker remains expressed in myofibers from mice with muscular dystrophy. Ablation of Myomaker from dystrophic myofibers results in reduced membrane damage, leading to a model where persistent fusogen expression in myofibers, in contrast to myoblasts, is harmful. METHODS Dox-inducible transgenic mice were developed to ectopically express Myomaker or Myomerger in the myofiber compartment of skeletal muscle. We quantified indices of myofiber membrane damage, such as serum creatine kinase and IgM+ myofibers, and assessed general muscle histology, including central nucleation, myofiber size, and fibrosis. RESULTS Myomaker or Myomerger expression in myofibers independently caused membrane damage at acute time points. This damage led to muscle pathology, manifesting with centrally nucleated myofibers and muscle atrophy. Dual expression of both Myomaker and Myomerger in myofibers exacerbated several aspects of muscle pathology compared to expression of either fusogen by itself. CONCLUSIONS These data reveal that while myofibers can tolerate some level of Myomaker and Myomerger, expression of a single fusogen above a threshold or co-expression of both fusogens is damaging to myofibers. These results explain the paradigm that their expression in myofibers can have deleterious consequences in muscle pathologies and highlight the need for their highly restricted expression during myogenesis and fusion.
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Affiliation(s)
- Phillip C Witcher
- Division of Molecular Cardiovascular Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - Chengyi Sun
- Division of Molecular Cardiovascular Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - Douglas P Millay
- Division of Molecular Cardiovascular Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA.
- Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH, 45229, USA.
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8
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MYTHO is a novel regulator of skeletal muscle autophagy and integrity. Nat Commun 2023; 14:1199. [PMID: 36864049 PMCID: PMC9981687 DOI: 10.1038/s41467-023-36817-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Accepted: 02/17/2023] [Indexed: 03/04/2023] Open
Abstract
Autophagy is a critical process in the regulation of muscle mass, function and integrity. The molecular mechanisms regulating autophagy are complex and still partly understood. Here, we identify and characterize a novel FoxO-dependent gene, d230025d16rik which we named Mytho (Macroautophagy and YouTH Optimizer), as a regulator of autophagy and skeletal muscle integrity in vivo. Mytho is significantly up-regulated in various mouse models of skeletal muscle atrophy. Short term depletion of MYTHO in mice attenuates muscle atrophy caused by fasting, denervation, cancer cachexia and sepsis. While MYTHO overexpression is sufficient to trigger muscle atrophy, MYTHO knockdown results in a progressive increase in muscle mass associated with a sustained activation of the mTORC1 signaling pathway. Prolonged MYTHO knockdown is associated with severe myopathic features, including impaired autophagy, muscle weakness, myofiber degeneration, and extensive ultrastructural defects, such as accumulation of autophagic vacuoles and tubular aggregates. Inhibition of the mTORC1 signaling pathway in mice using rapamycin treatment attenuates the myopathic phenotype triggered by MYTHO knockdown. Skeletal muscles from human patients diagnosed with myotonic dystrophy type 1 (DM1) display reduced Mytho expression, activation of the mTORC1 signaling pathway and impaired autophagy, raising the possibility that low Mytho expression might contribute to the progression of the disease. We conclude that MYTHO is a key regulator of muscle autophagy and integrity.
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9
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Cao R, Chen P, Wang H, Jing H, Zhang H, Xing G, Luo B, Pan J, Yu Z, Xiong WC, Mei L. Intrafusal-fiber LRP4 for muscle spindle formation and maintenance in adult and aged animals. Nat Commun 2023; 14:744. [PMID: 36765071 PMCID: PMC9918736 DOI: 10.1038/s41467-023-36454-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2022] [Accepted: 01/30/2023] [Indexed: 02/12/2023] Open
Abstract
Proprioception is sensed by muscle spindles for precise locomotion and body posture. Unlike the neuromuscular junction (NMJ) for muscle contraction which has been well studied, mechanisms of spindle formation are not well understood. Here we show that sensory nerve terminals are disrupted by the mutation of Lrp4, a gene required for NMJ formation; inducible knockout of Lrp4 in adult mice impairs sensory synapses and movement coordination, suggesting that LRP4 is required for spindle formation and maintenance. LRP4 is critical to the expression of Egr3 during development; in adult mice, it interacts in trans with APP and APLP2 on sensory terminals. Finally, spindle sensory endings and function are impaired in aged mice, deficits that could be diminished by LRP4 expression. These observations uncovered LRP4 as an unexpected regulator of muscle spindle formation and maintenance in adult and aged animals and shed light on potential pathological mechanisms of abnormal muscle proprioception.
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Affiliation(s)
- Rangjuan Cao
- Department of Neurosciences, School of Medicine, Case Western Reserve University, Cleveland, OH, 44106, USA.,Department of Hand and Foot Surgery, China-Japan Union Hospital of Jilin University, Changchun, China
| | - Peng Chen
- Department of Neurosciences, School of Medicine, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Hongsheng Wang
- Department of Neurosciences, School of Medicine, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Hongyang Jing
- Department of Neurosciences, School of Medicine, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Hongsheng Zhang
- Department of Neurosciences, School of Medicine, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Guanglin Xing
- Department of Neurosciences, School of Medicine, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Bin Luo
- Department of Neurosciences, School of Medicine, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Jinxiu Pan
- Department of Neurosciences, School of Medicine, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Zheng Yu
- Department of Neurosciences, School of Medicine, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Wen-Cheng Xiong
- Department of Neurosciences, School of Medicine, Case Western Reserve University, Cleveland, OH, 44106, USA. .,Louis Stokes Cleveland Veterans Affairs Medical Center, Cleveland, OH, 44106, USA.
| | - Lin Mei
- Department of Neurosciences, School of Medicine, Case Western Reserve University, Cleveland, OH, 44106, USA. .,Louis Stokes Cleveland Veterans Affairs Medical Center, Cleveland, OH, 44106, USA.
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10
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Baraldo M, Zorzato S, Dondjang AHT, Geremia A, Nogara L, Dumitras AG, Canato M, Marcucci L, Nolte H, Blaauw B. Inducible deletion of raptor and mTOR from adult skeletal muscle impairs muscle contractility and relaxation. J Physiol 2022; 600:5055-5075. [PMID: 36255030 DOI: 10.1113/jp283686] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Accepted: 09/20/2022] [Indexed: 01/05/2023] Open
Abstract
Skeletal muscle weakness has been associated with different pathological conditions, including sarcopenia and muscular dystrophy, and is accompanied by altered mammalian target of rapamycin (mTOR) signalling. We wanted to elucidate the functional role of mTOR in muscle contractility. Most loss-of-function studies for mTOR signalling have used the drug rapamycin to inhibit some of the signalling downstream of mTOR. However, given that rapamycin does not inhibit all mTOR signalling completely, we generated a double knockout for mTOR and for the scaffold protein of mTORC1, raptor, in skeletal muscle. We found that double knockout in mice results in a more severe phenotype compared with deletion of raptor or mTOR alone. Indeed, these animals display muscle weakness, increased fibre denervation and a slower muscle relaxation following tetanic stimulation. This is accompanied by a shift towards slow-twitch fibres and changes in the expression levels of calcium-related genes, such as Serca1 and Casq1. Double knockout mice show a decrease in calcium decay kinetics after tetanus in vivo, suggestive of a reduced calcium reuptake. In addition, RNA sequencing analysis revealed that many downregulated genes, such as Tcap and Fhod3, are linked to sarcomere organization. These results suggest a key role for mTOR signalling in maintaining proper fibre relaxation in skeletal muscle. KEY POINTS: Skeletal muscle wasting and weakness have been associated with different pathological conditions, including sarcopenia and muscular dystrophy, and are accompanied by altered mammalian target of rapamycin (mTOR) signalling. Mammalian target of rapamycin plays a crucial role in the maintenance of muscle mass and functionality. We found that the loss of both mTOR and raptor results in contractile abnormalities, with severe muscle weakness and delayed relaxation following tetanic stimulation. These results are associated with alterations in the expression of genes involved in sarcomere organization and calcium handling and with an impairment in calcium reuptake after contraction. Taken together, these results provide a mechanistic insight into the role of mTOR in muscle contractility.
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Affiliation(s)
- Martina Baraldo
- Venetian Institute of Molecular Medicine (VIMM), Padova, Italy.,Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Sabrina Zorzato
- Venetian Institute of Molecular Medicine (VIMM), Padova, Italy
| | - Achille Homère Tchampda Dondjang
- Venetian Institute of Molecular Medicine (VIMM), Padova, Italy.,Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Alessia Geremia
- Venetian Institute of Molecular Medicine (VIMM), Padova, Italy.,Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Leonardo Nogara
- Venetian Institute of Molecular Medicine (VIMM), Padova, Italy.,Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Ana Georgia Dumitras
- Venetian Institute of Molecular Medicine (VIMM), Padova, Italy.,Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Marta Canato
- Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Lorenzo Marcucci
- Department of Biomedical Sciences, University of Padova, Padova, Italy.,Center for Biosystems Dynamics Research, RIKEN, Suita, Japan
| | - Hendrik Nolte
- Institute for Genetics, Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany.,Center for Molecular Medicine (CMMC), University of Cologne, Cologne, Germany
| | - Bert Blaauw
- Venetian Institute of Molecular Medicine (VIMM), Padova, Italy.,Department of Biomedical Sciences, University of Padova, Padova, Italy
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11
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Chivet M, McCluskey M, Nicot AS, Brocard J, Beaufils M, Giovannini D, Giannesini B, Poreau B, Brocard J, Humbert S, Saudou F, Fauré J, Marty I. Huntingtin regulates calcium fluxes in skeletal muscle. J Gen Physiol 2022; 155:213700. [PMID: 36409218 PMCID: PMC9682417 DOI: 10.1085/jgp.202213103] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Revised: 09/09/2022] [Accepted: 09/03/2022] [Indexed: 11/22/2022] Open
Abstract
The expression of the Huntingtin protein, well known for its involvement in the neurodegenerative Huntington's disease, has been confirmed in skeletal muscle. The impact of HTT deficiency was studied in human skeletal muscle cell lines and in a mouse model with inducible and muscle-specific HTT deletion. Characterization of calcium fluxes in the knock-out cell lines demonstrated a reduction in excitation-contraction (EC) coupling, related to an alteration in the coupling between the dihydropyridine receptor and the ryanodine receptor, and an increase in the amount of calcium stored within the sarcoplasmic reticulum, linked to the hyperactivity of store-operated calcium entry (SOCE). Immunoprecipitation experiments demonstrated an association of HTT with junctophilin 1 (JPH1) and stromal interaction molecule 1 (STIM1), both providing clues on the functional effects of HTT deletion on calcium fluxes. Characterization of muscle strength and muscle anatomy of the muscle-specific HTT-KO mice demonstrated that HTT deletion induced moderate muscle weakness and mild muscle atrophy associated with histological abnormalities, similar to the phenotype observed in tubular aggregate myopathy. Altogether, this study points toward the hypotheses of the involvement of HTT in EC coupling via its interaction with JPH1, and on SOCE via its interaction with JPH1 and/or STIM1.
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Affiliation(s)
- Mathilde Chivet
- CHU Grenoble Alpes, Grenoble Institut Neurosciences, INSERM, U1216, Université Grenoble Alpes, Grenoble, France
| | - Maximilian McCluskey
- CHU Grenoble Alpes, Grenoble Institut Neurosciences, INSERM, U1216, Université Grenoble Alpes, Grenoble, France
| | - Anne Sophie Nicot
- CHU Grenoble Alpes, Grenoble Institut Neurosciences, INSERM, U1216, Université Grenoble Alpes, Grenoble, France
| | - Julie Brocard
- CHU Grenoble Alpes, Grenoble Institut Neurosciences, INSERM, U1216, Université Grenoble Alpes, Grenoble, France
| | - Mathilde Beaufils
- CHU Grenoble Alpes, Grenoble Institut Neurosciences, INSERM, U1216, Université Grenoble Alpes, Grenoble, France
| | - Diane Giovannini
- CHU Grenoble Alpes, Grenoble Institut Neurosciences, INSERM, U1216, Université Grenoble Alpes, Grenoble, France
| | - Benoit Giannesini
- Centre National de la Recherche Scientifique, Centre de Résonance Magnétique Biologique et Médicale, Aix Marseille University, Marseille, France
| | - Brice Poreau
- CHU Grenoble Alpes, Grenoble Institut Neurosciences, INSERM, U1216, Université Grenoble Alpes, Grenoble, France
| | - Jacques Brocard
- CHU Grenoble Alpes, Grenoble Institut Neurosciences, INSERM, U1216, Université Grenoble Alpes, Grenoble, France
| | - Sandrine Humbert
- CHU Grenoble Alpes, Grenoble Institut Neurosciences, INSERM, U1216, Université Grenoble Alpes, Grenoble, France
| | - Frédéric Saudou
- CHU Grenoble Alpes, Grenoble Institut Neurosciences, INSERM, U1216, Université Grenoble Alpes, Grenoble, France
| | - Julien Fauré
- CHU Grenoble Alpes, Grenoble Institut Neurosciences, INSERM, U1216, Université Grenoble Alpes, Grenoble, France
| | - Isabelle Marty
- CHU Grenoble Alpes, Grenoble Institut Neurosciences, INSERM, U1216, Université Grenoble Alpes, Grenoble, France,Correspondence to Isabelle Marty:
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12
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Inter-organellar and systemic responses to impaired mitochondrial matrix protein import in skeletal muscle. Commun Biol 2022; 5:1060. [PMID: 36198903 PMCID: PMC9534917 DOI: 10.1038/s42003-022-04034-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Accepted: 09/25/2022] [Indexed: 12/16/2022] Open
Abstract
Effective protein import from cytosol is critical for mitochondrial functions and metabolic regulation. We describe here the mammalian muscle-specific and systemic consequences to disrupted mitochondrial matrix protein import by targeted deletion of the mitochondrial HSP70 co-chaperone GRPEL1. Muscle-specific loss of GRPEL1 caused rapid muscle atrophy, accompanied by shut down of oxidative phosphorylation and mitochondrial fatty acid oxidation, and excessive triggering of proteotoxic stress responses. Transcriptome analysis identified new responders to mitochondrial protein import toxicity, such as the neurological disease-linked intermembrane space protein CHCHD10. Besides communication with ER and nucleus, we identified crosstalk of distressed mitochondria with peroxisomes, in particular the induction of peroxisomal Acyl-CoA oxidase 2 (ACOX2), which we propose as an ATF4-regulated peroxisomal marker of integrated stress response. Metabolic profiling indicated fatty acid enrichment in muscle, a shift in TCA cycle intermediates in serum and muscle, and dysregulated bile acids. Our results demonstrate the fundamental importance of GRPEL1 and provide a robust model for detecting mammalian inter-organellar and systemic responses to impaired mitochondrial matrix protein import and folding.
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13
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Hirata Y, Nomura K, Kato D, Tachibana Y, Niikura T, Uchiyama K, Hosooka T, Fukui T, Oe K, Kuroda R, Hara Y, Adachi T, Shibasaki K, Wake H, Ogawa W. A Piezo1/KLF15/IL-6 axis mediates immobilization-induced muscle atrophy. J Clin Invest 2022; 132:1-13. [PMID: 35290243 PMCID: PMC9159676 DOI: 10.1172/jci154611] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Accepted: 03/01/2022] [Indexed: 11/17/2022] Open
Abstract
Although immobility is a common cause of muscle atrophy, the mechanism underlying this causality is unclear. We here show that Krüppel-like factor 15 (KLF15) and IL-6 are upregulated in skeletal muscle of limb-immobilized mice and that mice with KLF15 deficiency in skeletal muscle or with systemic IL-6 deficiency are protected from immobility-induced muscle atrophy. A newly developed Ca2+ bioimaging revealed that the cytosolic Ca2+ concentration ([Ca2+]i) of skeletal muscle is reduced to below the basal level by immobilization, which is associated with the downregulation of Piezo1. Acute disruption of Piezo1 in skeletal muscle induced Klf15 and Il6 expression as well as muscle atrophy, which was prevented by antibodies against IL-6. A role for the Piezo1/KLF15/IL-6 axis in immobility-induced muscle atrophy was validated in human samples. Our results thus uncover a paradigm for Ca2+ signaling in that a decrease in [Ca2+]i from the basal level triggers a defined biological event.
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Affiliation(s)
- Yu Hirata
- Division of Diabetes and Endocrinology, Department of Internal Medicine, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Kazuhiro Nomura
- Division of Diabetes and Endocrinology, Department of Internal Medicine, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Daisuke Kato
- Department of Anatomy and Molecular Cell Biology, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Yoshihisa Tachibana
- Department of Physiology and Cell Biology, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Takahiro Niikura
- Department of Orthopaedic Surgery, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Kana Uchiyama
- Division of Diabetes and Endocrinology, Department of Internal Medicine, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Tetsuya Hosooka
- Division of Diabetes and Endocrinology, Department of Internal Medicine, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Tomoaki Fukui
- Department of Orthopaedic Surgery, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Keisuke Oe
- Department of Orthopaedic Surgery, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Ryosuke Kuroda
- Department of Orthopaedic Surgery, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Yuji Hara
- Department of Integrative Physiology, School of Pharmaceutical Sciences, University of Shizuoka, Shizuoka, Japan
| | - Takahiro Adachi
- Department of Precision Health, Medical Research Institute, Tokyo Medical and Dental University, Tokyo, Japan
| | - Koji Shibasaki
- Laboratory of Neurochemistry, Graduate School of Human Health Science, University of Nagasaki, Nagasaki, Japan
| | - Hiroaki Wake
- Department of Anatomy and Molecular Cell Biology, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Wataru Ogawa
- Division of Diabetes and Endocrinology, Department of Internal Medicine, Kobe University Graduate School of Medicine, Kobe, Japan
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14
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Wilson RJ, Lyons SP, Koves TR, Bryson VG, Zhang H, Li T, Crown SB, Ding JD, Grimsrud PA, Rosenberg PB, Muoio DM. Disruption of STIM1-mediated Ca 2+ sensing and energy metabolism in adult skeletal muscle compromises exercise tolerance, proteostasis, and lean mass. Mol Metab 2022; 57:101429. [PMID: 34979330 PMCID: PMC8814391 DOI: 10.1016/j.molmet.2021.101429] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Revised: 12/22/2021] [Accepted: 12/28/2021] [Indexed: 12/12/2022] Open
Abstract
OBJECTIVE Stromal interaction molecule 1 (STIM1) is a single-pass transmembrane endoplasmic/sarcoplasmic reticulum (E/SR) protein recognized for its role in a store operated Ca2+ entry (SOCE), an ancient and ubiquitous signaling pathway. Whereas STIM1 is known to be indispensable during development, its biological and metabolic functions in mature muscles remain unclear. METHODS Conditional and tamoxifen inducible muscle STIM1 knock-out mouse models were coupled with multi-omics tools and comprehensive physiology to understand the role of STIM1 in regulating SOCE, mitochondrial quality and bioenergetics, and whole-body energy homeostasis. RESULTS This study shows that STIM1 is abundant in adult skeletal muscle, upregulated by exercise, and is present at SR-mitochondria interfaces. Inducible tissue-specific deletion of STIM1 (iSTIM1 KO) in adult muscle led to diminished lean mass, reduced exercise capacity, and perturbed fuel selection in the settings of energetic stress, without affecting whole-body glucose tolerance. Proteomics and phospho-proteomics analyses of iSTIM1 KO muscles revealed molecular signatures of low-grade E/SR stress and broad activation of processes and signaling networks involved in proteostasis. CONCLUSION These results show that STIM1 regulates cellular and mitochondrial Ca2+ dynamics, energy metabolism and proteostasis in adult skeletal muscles. Furthermore, these findings provide insight into the pathophysiology of muscle diseases linked to disturbances in STIM1-dependent Ca2+ handling.
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Affiliation(s)
- Rebecca J Wilson
- Duke Molecular Physiology Institute, and Sarah W. Stedman Nutrition and Metabolism Center, Duke University School of Medicine, Durham, NC 27701, USA
| | - Scott P Lyons
- Duke Molecular Physiology Institute, and Sarah W. Stedman Nutrition and Metabolism Center, Duke University School of Medicine, Durham, NC 27701, USA
| | - Timothy R Koves
- Duke Molecular Physiology Institute, and Sarah W. Stedman Nutrition and Metabolism Center, Duke University School of Medicine, Durham, NC 27701, USA; Department of Medicine, Division of Geriatrics, Duke University School of Medicine, Durham, NC 27705, USA
| | - Victoria G Bryson
- Duke Molecular Physiology Institute, and Sarah W. Stedman Nutrition and Metabolism Center, Duke University School of Medicine, Durham, NC 27701, USA; Department of Medicine, Division of Cardiology, Duke University School of Medicine, Durham, NC 27705, USA
| | - Hengtao Zhang
- Duke Molecular Physiology Institute, and Sarah W. Stedman Nutrition and Metabolism Center, Duke University School of Medicine, Durham, NC 27701, USA; Department of Medicine, Division of Cardiology, Duke University School of Medicine, Durham, NC 27705, USA
| | - TianYu Li
- Duke Molecular Physiology Institute, and Sarah W. Stedman Nutrition and Metabolism Center, Duke University School of Medicine, Durham, NC 27701, USA; Department of Medicine, Division of Cardiology, Duke University School of Medicine, Durham, NC 27705, USA
| | - Scott B Crown
- Duke Molecular Physiology Institute, and Sarah W. Stedman Nutrition and Metabolism Center, Duke University School of Medicine, Durham, NC 27701, USA
| | - Jin-Dong Ding
- Department of Medicine, Division of Ophthalmology, Duke University School of Medicine, Durham, NC 27705, USA
| | - Paul A Grimsrud
- Duke Molecular Physiology Institute, and Sarah W. Stedman Nutrition and Metabolism Center, Duke University School of Medicine, Durham, NC 27701, USA; Department of Medicine, Division of Endocrinology, Metabolism, and Nutrition, Duke University School of Medicine, Durham, NC 27705, USA
| | - Paul B Rosenberg
- Duke Molecular Physiology Institute, and Sarah W. Stedman Nutrition and Metabolism Center, Duke University School of Medicine, Durham, NC 27701, USA; Department of Medicine, Division of Cardiology, Duke University School of Medicine, Durham, NC 27705, USA
| | - Deborah M Muoio
- Duke Molecular Physiology Institute, and Sarah W. Stedman Nutrition and Metabolism Center, Duke University School of Medicine, Durham, NC 27701, USA; Department of Medicine, Division of Endocrinology, Metabolism, and Nutrition, Duke University School of Medicine, Durham, NC 27705, USA; Department of Pharmacology and Cancer Biology, Duke University School of Medicine, Durham, NC 27705, USA.
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15
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Geremia A, Sartori R, Baraldo M, Nogara L, Balmaceda V, Dumitras GA, Ciciliot S, Scalabrin M, Nolte H, Blaauw B. Activation of Akt-mTORC1 signalling reverts cancer-dependent muscle wasting. J Cachexia Sarcopenia Muscle 2022; 13:648-661. [PMID: 34741441 PMCID: PMC8818597 DOI: 10.1002/jcsm.12854] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Revised: 10/04/2021] [Accepted: 10/07/2021] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Cancer-related muscle wasting occurs in most cancer patients. An important regulator of adult muscle mass and function is the Akt-mTORC1 pathway. While Akt-mTORC1 signalling is important for adult muscle homeostasis, it is also a major target of numerous cancer treatments. Which role Akt-mTORC1 signalling plays during cancer cachexia in muscle is currently not known. Here, we aimed to determine how activation or inactivation of the pathway affects skeletal muscle during cancer cachexia. METHODS We used inducible, muscle-specific Raptor ko (mTORC1) mice to determine the effect of reduced mTOR signalling during cancer cachexia. On the contrary, in order to understand if skeletal muscles maintain their anabolic capacity and if activation of Akt-mTORC1 signalling can reverse cancer cachexia, we generated mice in which we can inducibly activate Akt specifically in skeletal muscles. RESULTS We found that mTORC1 signalling is impaired during cancer cachexia, using the Lewis lung carcinoma and C26 colon cancer model, and is accompanied by a reduction in protein synthesis rates of 57% (P < 0.01). Further reduction of mTOR signalling, as seen in Raptor ko animals, leads to a 1.5-fold increase in autophagic flux (P > 0.001), but does not further increase muscle wasting. On the other hand, activation of Akt-mTORC1 signalling in already cachectic animals completely reverses the 15-20% loss in muscle mass and force (P < 0.001). Interestingly, Akt activation only in skeletal muscle completely normalizes the transcriptional deregulation observed in cachectic muscle, despite having no effect on tumour size or spleen mass. In addition to stimulating muscle growth, it is also sufficient to prevent the increase in protein degradation normally observed in muscles from tumour-bearing animals. CONCLUSIONS Here, we show that activation of Akt-mTORC1 signalling is sufficient to completely revert cancer-dependent muscle wasting. Intriguingly, these results show that skeletal muscle maintains its anabolic capacities also during cancer cachexia, possibly giving a rationale behind some of the beneficial effects observed in exercise in cancer patients.
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Affiliation(s)
- Alessia Geremia
- Veneto Institute of Molecular Medicine (VIMM), Padua, Italy.,Department of Biomedical Sciences, University of Padua, Padua, Italy
| | | | - Martina Baraldo
- Veneto Institute of Molecular Medicine (VIMM), Padua, Italy.,Department of Biomedical Sciences, University of Padua, Padua, Italy
| | - Leonardo Nogara
- Veneto Institute of Molecular Medicine (VIMM), Padua, Italy.,Department of Biomedical Sciences, University of Padua, Padua, Italy
| | | | - Georgia Ana Dumitras
- Veneto Institute of Molecular Medicine (VIMM), Padua, Italy.,Department of Biomedical Sciences, University of Padua, Padua, Italy
| | | | - Marco Scalabrin
- Veneto Institute of Molecular Medicine (VIMM), Padua, Italy.,Department of Biomedical Sciences, University of Padua, Padua, Italy
| | - Hendrik Nolte
- Max Planck Institute for Biology of Ageing, Cologne, Germany
| | - Bert Blaauw
- Veneto Institute of Molecular Medicine (VIMM), Padua, Italy.,Department of Biomedical Sciences, University of Padua, Padua, Italy
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16
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Krstic J, Reinisch I, Schindlmaier K, Galhuber M, Riahi Z, Berger N, Kupper N, Moyschewitz E, Auer M, Michenthaler H, Nössing C, Depaoli MR, Ramadani-Muja J, Usluer S, Stryeck S, Pichler M, Rinner B, Deutsch AJA, Reinisch A, Madl T, Chiozzi RZ, Heck AJR, Huch M, Malli R, Prokesch A. Fasting improves therapeutic response in hepatocellular carcinoma through p53-dependent metabolic synergism. SCIENCE ADVANCES 2022; 8:eabh2635. [PMID: 35061544 PMCID: PMC8782451 DOI: 10.1126/sciadv.abh2635] [Citation(s) in RCA: 36] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Accepted: 11/29/2021] [Indexed: 05/03/2023]
Abstract
Cancer cells voraciously consume nutrients to support their growth, exposing metabolic vulnerabilities that can be therapeutically exploited. Here, we show in hepatocellular carcinoma (HCC) cells, xenografts, and patient-derived organoids that fasting improves sorafenib efficacy and acts synergistically to sensitize sorafenib-resistant HCC. Mechanistically, sorafenib acts noncanonically as an inhibitor of mitochondrial respiration, causing resistant cells to depend on glycolysis for survival. Fasting, through reduction in glucose and impeded AKT/mTOR signaling, prevents this Warburg shift. Regulating glucose transporter and proapoptotic protein expression, p53 is necessary and sufficient for the sorafenib-sensitizing effect of fasting. p53 is also crucial for fasting-mediated improvement of sorafenib efficacy in an orthotopic HCC mouse model. Together, our data suggest fasting and sorafenib as rational combination therapy for HCC with intact p53 signaling. As HCC therapy is currently severely limited by resistance, these results should instigate clinical studies aimed at improving therapy response in advanced-stage HCC.
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Affiliation(s)
- Jelena Krstic
- Gottfried Schatz Research Center for Cell Signaling, Metabolism and Aging, Division of Cell Biology, Histology and Embryology, Medical University of Graz, 8010 Graz, Austria
| | - Isabel Reinisch
- Gottfried Schatz Research Center for Cell Signaling, Metabolism and Aging, Division of Cell Biology, Histology and Embryology, Medical University of Graz, 8010 Graz, Austria
| | - Katharina Schindlmaier
- Gottfried Schatz Research Center for Cell Signaling, Metabolism and Aging, Division of Cell Biology, Histology and Embryology, Medical University of Graz, 8010 Graz, Austria
| | - Markus Galhuber
- Gottfried Schatz Research Center for Cell Signaling, Metabolism and Aging, Division of Cell Biology, Histology and Embryology, Medical University of Graz, 8010 Graz, Austria
| | - Zina Riahi
- Gottfried Schatz Research Center for Cell Signaling, Metabolism and Aging, Division of Cell Biology, Histology and Embryology, Medical University of Graz, 8010 Graz, Austria
| | - Natascha Berger
- Gottfried Schatz Research Center for Cell Signaling, Metabolism and Aging, Division of Cell Biology, Histology and Embryology, Medical University of Graz, 8010 Graz, Austria
- Department of Obstetrics and Gynecology, Medical University of Graz, 8036 Graz, Austria
| | - Nadja Kupper
- Gottfried Schatz Research Center for Cell Signaling, Metabolism and Aging, Division of Cell Biology, Histology and Embryology, Medical University of Graz, 8010 Graz, Austria
| | - Elisabeth Moyschewitz
- Gottfried Schatz Research Center for Cell Signaling, Metabolism and Aging, Division of Cell Biology, Histology and Embryology, Medical University of Graz, 8010 Graz, Austria
| | - Martina Auer
- Gottfried Schatz Research Center for Cell Signaling, Metabolism and Aging, Division of Cell Biology, Histology and Embryology, Medical University of Graz, 8010 Graz, Austria
| | - Helene Michenthaler
- Gottfried Schatz Research Center for Cell Signaling, Metabolism and Aging, Division of Cell Biology, Histology and Embryology, Medical University of Graz, 8010 Graz, Austria
| | - Christoph Nössing
- Gottfried Schatz Research Center for Cell Signaling, Metabolism and Aging, Division of Cell Biology, Histology and Embryology, Medical University of Graz, 8010 Graz, Austria
- Cancer Research UK Beatson Institute, Garscube Estate, Glasgow, UK
| | - Maria R. Depaoli
- Gottfried Schatz Research Center for Cell Signaling, Metabolism and Aging, Division of Molecular Biology and Biochemistry, Medical University of Graz, 8010 Graz, Austria
| | - Jeta Ramadani-Muja
- Gottfried Schatz Research Center for Cell Signaling, Metabolism and Aging, Division of Molecular Biology and Biochemistry, Medical University of Graz, 8010 Graz, Austria
| | - Sinem Usluer
- Gottfried Schatz Research Center for Cell Signaling, Metabolism and Aging, Division of Molecular Biology and Biochemistry, Medical University of Graz, 8010 Graz, Austria
| | - Sarah Stryeck
- Gottfried Schatz Research Center for Cell Signaling, Metabolism and Aging, Division of Molecular Biology and Biochemistry, Medical University of Graz, 8010 Graz, Austria
- Institute of Interactive Systems and Data Science, Graz University of Technology, 8010 Graz, Austria
- Know-Center GmbH, 8010 Graz, Austria
| | - Martin Pichler
- Division of Clinical Oncology, Department of Medicine, Comprehensive Cancer Center Graz, Medical University of Graz, 8036 Graz, Austria
| | - Beate Rinner
- Department for Biomedical Research, Medical University of Graz, Graz, Austria
| | - Alexander J. A. Deutsch
- Division of Hematology, Department of Internal Medicine, Medical University of Graz, 8036 Graz, Austria
| | - Andreas Reinisch
- Division of Hematology, Department of Internal Medicine, Medical University of Graz, 8036 Graz, Austria
- Division of Hematology, Department of Blood Group Serology and Transfusion Medicine Medical University of Graz, 8036 Graz, Austria
| | - Tobias Madl
- Gottfried Schatz Research Center for Cell Signaling, Metabolism and Aging, Division of Molecular Biology and Biochemistry, Medical University of Graz, 8010 Graz, Austria
- BioTechMed-Graz, 8010 Graz, Austria
| | - Riccardo Zenezini Chiozzi
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute of Pharmaceutical Sciences, Utrecht University, 3584CH Utrecht, Netherlands
- Netherlands Proteomics Center, 3584CH Utrecht, Netherlands
| | - Albert J. R. Heck
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute of Pharmaceutical Sciences, Utrecht University, 3584CH Utrecht, Netherlands
- Netherlands Proteomics Center, 3584CH Utrecht, Netherlands
| | - Meritxell Huch
- Max Planck Institute of Molecular Cell Biology and Genetics, 01307 Dresden, Germany
| | - Roland Malli
- Gottfried Schatz Research Center for Cell Signaling, Metabolism and Aging, Division of Molecular Biology and Biochemistry, Medical University of Graz, 8010 Graz, Austria
- BioTechMed-Graz, 8010 Graz, Austria
| | - Andreas Prokesch
- Gottfried Schatz Research Center for Cell Signaling, Metabolism and Aging, Division of Cell Biology, Histology and Embryology, Medical University of Graz, 8010 Graz, Austria
- BioTechMed-Graz, 8010 Graz, Austria
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17
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Meister J, Bone DBJ, Knudsen JR, Barella LF, Velenosi TJ, Akhmedov D, Lee RJ, Cohen AH, Gavrilova O, Cui Y, Karsenty G, Chen M, Weinstein LS, Kleinert M, Berdeaux R, Jensen TE, Richter EA, Wess J. Clenbuterol exerts antidiabetic activity through metabolic reprogramming of skeletal muscle cells. Nat Commun 2022; 13:22. [PMID: 35013148 PMCID: PMC8748640 DOI: 10.1038/s41467-021-27540-w] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Accepted: 11/24/2021] [Indexed: 12/14/2022] Open
Abstract
Activation of the sympathetic nervous system causes pronounced metabolic changes that are mediated by multiple adrenergic receptor subtypes. Systemic treatment with β2-adrenergic receptor agonists results in multiple beneficial metabolic effects, including improved glucose homeostasis. To elucidate the underlying cellular and molecular mechanisms, we chronically treated wild-type mice and several newly developed mutant mouse strains with clenbuterol, a selective β2-adrenergic receptor agonist. Clenbuterol administration caused pronounced improvements in glucose homeostasis and prevented the metabolic deficits in mouse models of β-cell dysfunction and insulin resistance. Studies with skeletal muscle-specific mutant mice demonstrated that these metabolic improvements required activation of skeletal muscle β2-adrenergic receptors and the stimulatory G protein, Gs. Unbiased transcriptomic and metabolomic analyses showed that chronic β2-adrenergic receptor stimulation caused metabolic reprogramming of skeletal muscle characterized by enhanced glucose utilization. These findings strongly suggest that agents targeting skeletal muscle metabolism by modulating β2-adrenergic receptor-dependent signaling pathways may prove beneficial as antidiabetic drugs.
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Affiliation(s)
- Jaroslawna Meister
- Molecular Signaling Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD, 20892, USA.
| | - Derek B J Bone
- Molecular Signaling Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD, 20892, USA
| | - Jonas R Knudsen
- Departments of Nutrition, Exercise and Sports, University of Copenhagen, København, Denmark
| | - Luiz F Barella
- Molecular Signaling Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD, 20892, USA
| | - Thomas J Velenosi
- Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, BC, Canada
| | - Dmitry Akhmedov
- Departments of Integrative Biology and Pharmacology, Houston Medical School, Houston, TX, 77030, USA
| | - Regina J Lee
- Molecular Signaling Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD, 20892, USA
| | - Amanda H Cohen
- Molecular Signaling Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD, 20892, USA
| | - Oksana Gavrilova
- Mouse Metabolism Core, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD, 20892, USA
| | - Yinghong Cui
- Molecular Signaling Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD, 20892, USA
| | - Gerard Karsenty
- Departments of Genetics and Development, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, USA
| | - Min Chen
- Metabolic Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD, 20892, USA
| | - Lee S Weinstein
- Metabolic Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD, 20892, USA
| | - Maximilian Kleinert
- Departments of Nutrition, Exercise and Sports, University of Copenhagen, København, Denmark
- Muscle Physiology and Metabolism Group, German Institute of Human Nutrition, Potsdam-Rehbrücke, Nuthetal, Germany
| | - Rebecca Berdeaux
- Departments of Integrative Biology and Pharmacology, Houston Medical School, Houston, TX, 77030, USA
| | - Thomas E Jensen
- Departments of Nutrition, Exercise and Sports, University of Copenhagen, København, Denmark
| | - Erik A Richter
- Departments of Nutrition, Exercise and Sports, University of Copenhagen, København, Denmark
| | - Jürgen Wess
- Molecular Signaling Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD, 20892, USA.
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18
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Knudsen JR, Persson KW, Meister J, Carl CS, Raun SH, Andersen NR, Sylow L, Kiens B, Jensen TE, Richter EA, Kleinert M. Exercise increases phosphorylation of the putative mTORC2 activity readout NDRG1 in human skeletal muscle. Am J Physiol Endocrinol Metab 2022; 322:E63-E73. [PMID: 34866401 PMCID: PMC8759970 DOI: 10.1152/ajpendo.00389.2021] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
In mice, exercise is suggested to activate the mechanistic target of rapamycin complex 2 (mTORC2) in skeletal muscle, and mTORC2 is required for normal muscle glucose uptake during exercise. Whether this translates to human skeletal muscle and what signaling pathways facilitate the exercise-induced mTORC2 activation is unknown. We herein tested the hypothesis that exercise increases mTORC2 activity in human skeletal muscle and investigated if β2-adrenergic receptor (AR) activation mediates exercise-induced mTORC2 activation. We examined several mTORC2 activity readouts (p-NDRG1 Thr346, p-Akt Ser473, p-mTOR S2481, and p-Akt Thr450) in human skeletal muscle biopsies after uphill walking or cycling exercise. In mouse muscles, we assessed mTORC2 activity readouts following acute activation of muscle β2-adrenergic or GS signaling and during in vivo and ex vivo muscle contractions. Exercise increased phosphorylation of NDRG1 Thr346 in human soleus, gastrocnemius, and vastus lateralis muscle, without changing p-Akt Ser473, p-Akt Thr450, and p-mTOR Ser2481. In mouse muscle, stimulation of β2-adrenergic or GS signaling and ex vivo contractions failed to increase p-NDRG1 Thr346, whereas in vivo contractions were sufficient to induce p-NDRG1 Thr346. In conclusion, the mTORC2 activity readout p-NDRG1 Thr346 is a novel exercise-responsive signaling protein in human skeletal muscle. Notably, contraction-induced p-NDRG1 Thr346 appears to require a systemic factor. Unlike exercise, and in contrast to published data obtained in cultured muscles cells, stimulation of β2-adrenergic signaling is not sufficient to trigger NDRG1 phosphorylation in mature mouse skeletal muscle.NEW & NOTEWORTHY The mTORC2 readout p-NDRG Thr346 is a novel exercise-responsive protein in human skeletal muscle. β2-AR and GS signaling are not sufficient to induce mTORC2 signaling in adult muscle. In vivo, but not ex vivo, contraction induced p-NDRG Thr346, which indicates requirement of a systemic factor for exercise-induced mTORC2 activation.
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Affiliation(s)
- Jonas R Knudsen
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Kaspar W Persson
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Jaroslawna Meister
- Molecular Signaling Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, Maryland
| | - Christian S Carl
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Steffen H Raun
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Nicoline R Andersen
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Lykke Sylow
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Bente Kiens
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Thomas E Jensen
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Erik A Richter
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Maximilian Kleinert
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
- Muscle Physiology and Metabolism Group, German Institute of Human Nutrition, Potsdam-Rehbruecke, Nuthetal, Germany
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19
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RhoA within myofibers controls satellite cell microenvironment to allow hypertrophic growth. iScience 2022; 25:103616. [PMID: 35106464 PMCID: PMC8786647 DOI: 10.1016/j.isci.2021.103616] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Revised: 08/02/2021] [Accepted: 12/09/2021] [Indexed: 12/13/2022] Open
Abstract
Adult skeletal muscle is a plastic tissue that can adapt its size to workload. Here, we show that RhoA within myofibers is needed for overload-induced hypertrophy by controlling satellite cell (SC) fusion to the growing myofibers without affecting protein synthesis. At the molecular level, we demonstrate that RhoA controls in a cell autonomous manner Erk1/2 activation and the expressions of extracellular matrix (ECM) regulators such as Mmp9/Mmp13/Adam8 and macrophage chemo-attractants such as Ccl3/Cx3cl1. Their decreased expression in RhoA mutants is associated with ECM and fibrillar collagen disorganization and lower macrophage infiltration. Moreover, matrix metalloproteinases inhibition and macrophage depletion in controls phenocopied the altered growth of RhoA mutants while having no effect in mutants showing that their action is RhoA-dependent. These findings unravel the implication of RhoA within myofibers, in the building of a permissive microenvironment for muscle hypertrophic growth and for SC accretion through ECM remodeling and inflammatory cell recruitment. RhoA within myofibers controls SC fusion and muscle hypertrophic growth RhoA controls the expression of Mmps and of macrophage chemoattractants (Ccl3/Cx3cl1) RhoA controls ECM remodeling and macrophage recruitment upon hypertrophy Mmp inhibition and macrophage depletion phenocopy the blunted growth of RhoA mutant muscles
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20
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In vivo metabolic effects after acute activation of skeletal muscle G s signaling. Mol Metab 2021; 55:101415. [PMID: 34883278 PMCID: PMC8728399 DOI: 10.1016/j.molmet.2021.101415] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/08/2021] [Revised: 11/21/2021] [Accepted: 12/02/2021] [Indexed: 11/21/2022] Open
Abstract
Objective The goal of this study was to determine the glucometabolic effects of acute activation of Gs signaling in skeletal muscle (SKM) in vivo and its contribution to whole-body glucose homeostasis. Methods To address this question, we studied mice that express a Gs-coupled designer G protein-coupled receptor (Gs-DREADD or GsD) selectively in skeletal muscle. We also identified two Gs-coupled GPCRs that are endogenously expressed by SKM at relatively high levels (β2-adrenergic receptor and CRF2 receptor) and studied the acute metabolic effects of activating these receptors in vivo by highly selective agonists (clenbuterol and urocortin 2 (UCN2), respectively). Results Acute stimulation of GsD signaling in SKM impaired glucose tolerance in lean and obese mice by decreasing glucose uptake selectively into SKM. The acute metabolic effects following agonist activation of β2-adrenergic and, potentially, CRF2 receptors appear primarily mediated by altered insulin release. Clenbuterol injection improved glucose tolerance by increasing insulin secretion in lean mice. In SKM, clenbuterol stimulated glycogen breakdown. UCN2 injection resulted in decreased glucose tolerance associated with lower plasma insulin levels. The acute metabolic effects of UCN2 were not mediated by SKM Gs signaling. Conclusions Selective activation of Gs signaling in SKM causes an acute increase in blood glucose levels. However, acute in vivo stimulation of endogenous Gs-coupled receptors enriched in SKM has only a limited impact on whole-body glucose homeostasis, most likely due to the fact that these receptors are also expressed by pancreatic islets where they modulate insulin release. A novel mouse model allowed us to study the in vivo metabolic effects of acute activation of Gs signaling in skeletal muscle (SKM). Acute stimulation of this pathway resulted in impaired glucose tolerance in lean and obese mice due to decreased glucose uptake by SKM. Acute treatment of mice with selective β2-adrenergic and CRF2 receptor agonists (both receptors couple to Gs and are enriched in SKM) resulted in complex in vivo metabolic outcomes, primarily due to altered insulin release. Our study provides an excellent example of how different tissue expression patterns of receptors can affect the acute effects of GPCR agonists on whole-body glucose homeostasis Our findings also highlight the importance of studying both acute and chronic effects of GPCR agonist treatment to properly assess translationally relevant metabolic outcomes.
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21
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Bhardwaj G, Penniman CM, Jena J, Suarez Beltran PA, Foster C, Poro K, Junck TL, Hinton AO, Souvenir R, Fuqua JD, Morales PE, Bravo-Sagua R, Sivitz WI, Lira VA, Abel ED, O'Neill BT. Insulin and IGF-1 receptors regulate complex-I dependent mitochondrial bioenergetics and supercomplexes via FoxOs in muscle. J Clin Invest 2021; 131:e146415. [PMID: 34343133 DOI: 10.1172/jci146415] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Accepted: 07/28/2021] [Indexed: 12/25/2022] Open
Abstract
Decreased skeletal muscle strength and mitochondrial dysfunction are characteristic of diabetes. Action of insulin and IGF-1 through insulin receptor (IR) and IGF-1 receptor (IGF1R) maintain muscle mass via suppression of FoxOs, but whether FoxO activation coordinates atrophy in concert with mitochondrial dysfunction is unknown. We show that mitochondrial respiration and complex-I activity were decreased in streptozotocin (STZ) diabetic muscle, but these defects were reversed following muscle-specific FoxO1/3/4 triple knockout in STZ-FoxO TKO. In the absence of systemic glucose or lipid abnormalities, muscle-specific IR knockout (M-IR-/-) or combined IR/IGF1R knockout (MIGIRKO) impaired mitochondrial respiration, decreased ATP production, and increased ROS. These mitochondrial abnormalities were not present in muscle-specific IR/IGF1R and FoxO1/3/4 quintuple knockout mice (M-QKO). Acute tamoxifen-inducible deletion of IR/IGF1R also decreased muscle pyruvate respiration, complex-I activity, and supercomplex assembly. Although autophagy was increased when IR/IGF1R were deleted in muscle, mitophagy was not increased. Mechanistically, RNA-seq revealed that complex-I core subunits were decreased in STZ-diabetic and MIGIRKO muscle, and these changes were not present with FoxO knockout in STZ-FoxO TKO and M-QKO. Thus, insulin-deficient diabetes or loss of insulin/IGF-1 action in muscle decreases complex-I driven mitochondrial respiration and supercomplex assembly, in part by FoxO-mediated repression of Complex-I subunit expression.
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Affiliation(s)
- Gourav Bhardwaj
- Department of Internal Medicine, Carver College of Medicine, University of Iowa, Iowa City, United States of America
| | - Christie M Penniman
- Department of Internal Medicine, Carver College of Medicine, University of Iowa, Iowa City, United States of America
| | - Jayashree Jena
- Department of Internal Medicine, Carver College of Medicine, University of Iowa, Iowa City, United States of America
| | - Pablo A Suarez Beltran
- Department of Internal Medicine, Carver College of Medicine, University of Iowa, Iowa City, United States of America
| | - Collin Foster
- Department of Internal Medicine, Carver College of Medicine, University of Iowa, Iowa City, United States of America
| | - Kennedy Poro
- Department of Internal Medicine, Carver College of Medicine, University of Iowa, Iowa City, United States of America
| | - Taylor L Junck
- Department of Internal Medicine, Carver College of Medicine, University of Iowa, Iowa City, United States of America
| | - Antentor O Hinton
- Department of Internal Medicine, Carver College of Medicine, University of Iowa, Iowa City, United States of America
| | - Rhonda Souvenir
- Department of Internal Medicine, Carver College of Medicine, University of Iowa, Iowa City, United States of America
| | - Jordan D Fuqua
- Department of Health and Human Physiology, University of Iowa, Iowa City, United States of America
| | - Pablo E Morales
- Advanced Center for Chronic Diseases (ACCDiS), Universidad de Chile, Santiago, Chile
| | - Roberto Bravo-Sagua
- Advanced Center for Chronic Diseases (ACCDiS), Universidad de Chile, Santiago, Chile
| | - William I Sivitz
- Department of Internal Medicine, Carver College of Medicine, University of Iowa, Iowa City, United States of America
| | - Vitor A Lira
- Department of Health and Human Physiology, University of Iowa, Iowa City, United States of America
| | - E Dale Abel
- Department of Internal Medicine, Carver College of Medicine, University of Iowa, Iowa City, United States of America
| | - Brian T O'Neill
- Department of Internal Medicine, Carver College of Medicine, University of Iowa, Iowa City, United States of America
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22
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Rovito D, Rerra AI, Ueberschlag-Pitiot V, Joshi S, Karasu N, Dacleu-Siewe V, Rayana KB, Ghaibour K, Parisotto M, Ferry A, Jelinsky SA, Laverny G, Klaholz BP, Sexton T, Billas IML, Duteil D, Metzger D. Myod1 and GR coordinate myofiber-specific transcriptional enhancers. Nucleic Acids Res 2021; 49:4472-4492. [PMID: 33836079 PMCID: PMC8096230 DOI: 10.1093/nar/gkab226] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Revised: 03/12/2021] [Accepted: 03/23/2021] [Indexed: 12/13/2022] Open
Abstract
Skeletal muscle is a dynamic tissue the size of which can be remodeled through the concerted actions of various cues. Here, we investigated the skeletal muscle transcriptional program and identified key tissue-specific regulatory genetic elements. Our results show that Myod1 is bound to numerous skeletal muscle enhancers in collaboration with the glucocorticoid receptor (GR) to control gene expression. Remarkably, transcriptional activation controlled by these factors occurs through direct contacts with the promoter region of target genes, via the CpG-bound transcription factor Nrf1, and the formation of Ctcf-anchored chromatin loops, in a myofiber-specific manner. Moreover, we demonstrate that GR negatively controls muscle mass and strength in mice by down-regulating anabolic pathways. Taken together, our data establish Myod1, GR and Nrf1 as key players of muscle-specific enhancer-promoter communication that orchestrate myofiber size regulation.
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Affiliation(s)
- Daniela Rovito
- Université de Strasbourg, CNRS UMR7104, INSERM U1258, IGBMC, F-67400 Illkirch, France
| | - Anna-Isavella Rerra
- Université de Strasbourg, CNRS UMR7104, INSERM U1258, IGBMC, F-67400 Illkirch, France
| | | | - Shilpy Joshi
- Université de Strasbourg, CNRS UMR7104, INSERM U1258, IGBMC, F-67400 Illkirch, France
| | - Nezih Karasu
- Université de Strasbourg, CNRS UMR7104, INSERM U1258, IGBMC, F-67400 Illkirch, France
| | - Vanessa Dacleu-Siewe
- Université de Strasbourg, CNRS UMR7104, INSERM U1258, IGBMC, F-67400 Illkirch, France
| | - Khalil Ben Rayana
- Université de Strasbourg, CNRS UMR7104, INSERM U1258, IGBMC, F-67400 Illkirch, France
| | - Kamar Ghaibour
- Université de Strasbourg, CNRS UMR7104, INSERM U1258, IGBMC, F-67400 Illkirch, France
| | - Maxime Parisotto
- Université de Strasbourg, CNRS UMR7104, INSERM U1258, IGBMC, F-67400 Illkirch, France
| | - Arnaud Ferry
- Centre de Recherche en Myologie, UMRS974-Sorbonne Université-INSERM U974-Association Institut de Myologie, France
| | - Scott A Jelinsky
- Department of Inflammation and Immunology, Pfizer Research, Cambridge, MA, USA
| | - Gilles Laverny
- Université de Strasbourg, CNRS UMR7104, INSERM U1258, IGBMC, F-67400 Illkirch, France
| | - Bruno P Klaholz
- Université de Strasbourg, CNRS UMR7104, INSERM U1258, IGBMC, F-67400 Illkirch, France
| | - Tom Sexton
- Université de Strasbourg, CNRS UMR7104, INSERM U1258, IGBMC, F-67400 Illkirch, France
| | - Isabelle M L Billas
- Université de Strasbourg, CNRS UMR7104, INSERM U1258, IGBMC, F-67400 Illkirch, France
| | - Delphine Duteil
- Université de Strasbourg, CNRS UMR7104, INSERM U1258, IGBMC, F-67400 Illkirch, France
| | - Daniel Metzger
- Université de Strasbourg, CNRS UMR7104, INSERM U1258, IGBMC, F-67400 Illkirch, France
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23
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Pelletier L, Petiot A, Brocard J, Giannesini B, Giovannini D, Sanchez C, Travard L, Chivet M, Beaufils M, Kutchukian C, Bendahan D, Metzger D, Franzini Armstrong C, Romero NB, Rendu J, Jacquemond V, Fauré J, Marty I. In vivo RyR1 reduction in muscle triggers a core-like myopathy. Acta Neuropathol Commun 2020; 8:192. [PMID: 33176865 PMCID: PMC7657350 DOI: 10.1186/s40478-020-01068-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Accepted: 10/27/2020] [Indexed: 12/16/2022] Open
Abstract
Mutations in the RYR1 gene, encoding the skeletal muscle calcium channel RyR1, lead to congenital myopathies, through expression of a channel with abnormal permeability and/or in reduced amount, but the direct functional whole organism consequences of exclusive reduction in RyR1 amount have never been studied. We have developed and characterized a mouse model with inducible muscle specific RYR1 deletion. Tamoxifen-induced recombination in the RYR1 gene at adult age resulted in a progressive reduction in the protein amount reaching a stable level of 50% of the initial amount, and was associated with a progressive muscle weakness and atrophy. Measurement of calcium fluxes in isolated muscle fibers demonstrated a reduction in the amplitude of RyR1-related calcium release mirroring the reduction in the protein amount. Alterations in the muscle structure were observed, with fibers atrophy, abnormal mitochondria distribution and membrane remodeling. An increase in the expression level of many proteins was observed, as well as an inhibition of the autophagy process. This model demonstrates that RyR1 reduction is sufficient to recapitulate most features of Central Core Disease, and accordingly similar alterations were observed in muscle biopsies from Dusty Core Disease patients (a subtype of Central Core Disease), pointing to common pathophysiological mechanisms related to RyR1 reduction.
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24
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Sulaeman A, Fine J, de Vargas-Machuca A, Vitorino SA, Wagner PD, Fruttiger M, Breen EC. Synergistic effect of vascular endothelial growth factor gene inactivation in endothelial cells and skeletal myofibres on muscle enzyme activity, capillary supply and endurance exercise in mice. Exp Physiol 2020; 105:2168-2177. [PMID: 32936962 DOI: 10.1113/ep088924] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Accepted: 09/15/2020] [Indexed: 12/18/2022]
Abstract
NEW FINDINGS What is the central question of this study? Does vascular endothelial growth factor (VEGF) expressed by both endothelial cells and skeletal myofibres maintain the number of skeletal muscle capillaries and regulate endurance exercise? What is the main finding and its importance? VEGF expressed by both endothelial cells and skeletal myofibres is not essential for maintaining capillary number but does contribute to exercise performance. ABSTRACT Many chronic diseases lead to exercise intolerance, with loss of skeletal muscle capillaries. While many muscle cell types (myofibres, satellite cells, endothelial cells, macrophages and fibroblasts) express vascular endothelial growth factor (VEGF), most muscle VEGF is stored in myofibre vesicles which can release VEGF to signal VEGF receptor-expressing cells. VEGF gene ablation in myofibres or endothelial cells alone does not cause capillary regression. We hypothesized that simultaneously deleting the endothelial cell (EC) and skeletal myofibre (Skm) VEGF gene would cause capillary regression and impair exercise performance. This was tested in adult mice by simultaneous conditional deletion of the VEGF gene (Skm/EC-VEGF-/- mice) through the use of VEGFLoxP, HSA-Cre-ERT2 and PDGFb-iCre-ERT2 transgenes. These double-deletion mice were compared to three control groups - WT, EC VEGF gene deletion alone and myofibre VEGF gene deletion alone. Three weeks after initiating gene deletion, Skm/EC-VEGF-/- mice, but not SkmVEGF-/- or EC-VEGF-/- mice, reached exhaustion 40 min sooner than WT mice in treadmill tests (P = 0.002). WT, SkmVEGF-/- and EC-VEGF-/- , but not Skm/EC-VEGF-/- , mice gained weight over the 3 weeks. Capillary density, fibre area and capillary: fibre ratio in soleus, plantaris, gastrocnemius and cardiac papillary muscle were similar across the groups. Phosphofructokinase and pyruvate dehydrogenase activities increased only in Skm/EC-VEGF-/- mice. These data suggest that deletion of the VEGF gene simultaneously in endothelial cells and myofibres, while reducing treadmill endurance and despite compensatory augmentation of glycolysis, is not required for muscle capillary maintenance. Reduced endurance remains unexplained, but may possibly be related to a role for VEGF in controlling perfusion of contracting muscle.
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Affiliation(s)
- Alexis Sulaeman
- Department of Medicine, University of California, San Diego, CA, USA
| | - Janelle Fine
- Department of Medicine, University of California, San Diego, CA, USA
| | | | - Steven A Vitorino
- Department of Medicine, University of California, San Diego, CA, USA
| | - Peter D Wagner
- Department of Medicine, University of California, San Diego, CA, USA
| | - Marcus Fruttiger
- UCL Institute of Ophthalmology, University College London, London, UK
| | - Ellen C Breen
- Department of Medicine, University of California, San Diego, CA, USA
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25
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Petrany MJ, Song T, Sadayappan S, Millay DP. Myocyte-derived Myomaker expression is required for regenerative fusion but exacerbates membrane instability in dystrophic myofibers. JCI Insight 2020; 5:136095. [PMID: 32310830 DOI: 10.1172/jci.insight.136095] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2019] [Accepted: 04/08/2020] [Indexed: 12/21/2022] Open
Abstract
Muscle progenitor cell fusion is required for the formation and regeneration of multinucleated skeletal muscle fibers. Chronic muscle regeneration in Duchenne muscular dystrophy (DMD) is characterized by ongoing fusion of satellite cell (SC) progeny, but the effects of fusion on disease and the mechanisms by which fusion is accomplished in this setting are not fully understood. Using the mdx mouse model of DMD, we deleted the fusogenic protein Myomaker in SCs or myofibers. Following deletion in SCs, mice displayed a complete lack of myocyte fusion, resulting in severe muscle loss, enhanced fibrosis, and significant functional decline. Reduction of Myomaker in mature myofibers in mdx mice, however, led to minimal alterations in fusion dynamics. Unexpectedly, myofiber-specific deletion of Myomaker resulted in improvement of disease phenotype, with enhanced function and decreased muscle damage. Our data indicate that Myomaker has divergent effects on dystrophic disease severity depending upon its compartment of expression. These findings show that myocyte fusion is absolutely required for effective regeneration in DMD, but persistent Myomaker expression in myofibers due to ongoing fusion may have unintended deleterious consequences for muscle integrity. Thus, sustained activation of a component of the myogenic program in dystrophic myofibers exacerbates disease.
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Affiliation(s)
- Michael J Petrany
- Division of Molecular Cardiovascular Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA
| | - Taejeong Song
- Department of Internal Medicine, Division of Cardiovascular Health and Disease, and
| | - Sakthivel Sadayappan
- Department of Internal Medicine, Division of Cardiovascular Health and Disease, and
| | - Douglas P Millay
- Division of Molecular Cardiovascular Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA.,Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
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26
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Baraldo M, Geremia A, Pirazzini M, Nogara L, Solagna F, Türk C, Nolte H, Romanello V, Megighian A, Boncompagni S, Kruger M, Sandri M, Blaauw B. Skeletal muscle mTORC1 regulates neuromuscular junction stability. J Cachexia Sarcopenia Muscle 2020; 11:208-225. [PMID: 31651100 PMCID: PMC7015238 DOI: 10.1002/jcsm.12496] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Revised: 08/12/2019] [Accepted: 08/25/2019] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND Skeletal muscle is a plastic tissue that can adapt to different stimuli. It is well established that Mammalian Target of Rapamycin Complex 1 (mTORC1) signalling is a key modulator in mediating increases in skeletal muscle mass and function. However, the role of mTORC1 signalling in adult skeletal muscle homeostasis is still not well defined. METHODS Inducible, muscle-specific Raptor and mTOR k.o. mice were generated. Muscles at 1 and 7 months after deletion were analysed to assess muscle histology and muscle force. RESULTS We found no change in muscle size or contractile properties 1 month after deletion. Prolonging deletion of Raptor to 7 months, however, leads to a very marked phenotype characterized by weakness, muscle regeneration, mitochondrial dysfunction, and autophagy impairment. Unexpectedly, reduced mTOR signalling in muscle fibres is accompanied by the appearance of markers of fibre denervation, like the increased expression of the neural cell adhesion molecule (NCAM). Both muscle-specific deletion of mTOR or Raptor, or the use of rapamycin, was sufficient to induce 3-8% of NCAM-positive fibres (P < 0.01), muscle fibrillation, and neuromuscular junction (NMJ) fragmentation in 24% of examined fibres (P < 0.001). Mechanistically, reactivation of autophagy with the small peptide Tat-beclin1 is sufficient to prevent mitochondrial dysfunction and the appearance of NCAM-positive fibres in Raptor k.o. muscles. CONCLUSIONS Our study shows that mTOR signalling in skeletal muscle fibres is critical for maintaining proper fibre innervation, preserving the NMJ structure in both the muscle fibre and the motor neuron. In addition, considering the beneficial effects of exercise in most pathologies affecting the NMJ, our findings suggest that part of these beneficial effects of exercise are through the well-established activation of mTORC1 in skeletal muscle during and after exercise.
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Affiliation(s)
- Martina Baraldo
- Venetian Institute of Molecular Medicine (VIMM), Padova, Italy.,Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Alessia Geremia
- Venetian Institute of Molecular Medicine (VIMM), Padova, Italy.,Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Marco Pirazzini
- Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Leonardo Nogara
- Venetian Institute of Molecular Medicine (VIMM), Padova, Italy.,Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Francesca Solagna
- Venetian Institute of Molecular Medicine (VIMM), Padova, Italy.,Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Clara Türk
- Institute for Genetics, Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), Cologne, Germany
| | - Hendrik Nolte
- Institute for Genetics, Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), Cologne, Germany
| | - Vanina Romanello
- Venetian Institute of Molecular Medicine (VIMM), Padova, Italy.,Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Aram Megighian
- Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Simona Boncompagni
- CeSI-Met-Center for Research on Ageing and Translational Medicine and DNICS, Department of Neuroscience, Imaging and Clinical Sciences, University G. d' Annunzio, Chieti, Italy
| | - Marcus Kruger
- 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, Cologne, Germany
| | - Marco Sandri
- Venetian Institute of Molecular Medicine (VIMM), Padova, Italy.,Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Bert Blaauw
- Venetian Institute of Molecular Medicine (VIMM), Padova, Italy.,Department of Biomedical Sciences, University of Padova, Padova, Italy
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27
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Cannon DT, Rodewohl L, Adams V, Breen EC, Bowen TS. Skeletal myofiber VEGF deficiency leads to mitochondrial, structural, and contractile alterations in mouse diaphragm. J Appl Physiol (1985) 2019; 127:1360-1369. [PMID: 31487223 DOI: 10.1152/japplphysiol.00779.2018] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Diaphragm dysfunction accompanies cardiopulmonary disease and impaired oxygen delivery. Vascular endothelial growth factor (VEGF) regulates oxygen delivery through angiogenesis, capillary maintenance, and contraction-induced perfusion. We hypothesized that myofiber-specific VEGF deficiency contributes to diaphragm weakness and fatigability. Diaphragm protein expression, capillarity and fiber morphology, mitochondrial respiration and hydrogen peroxide (H2O2) generation, and contractile function were compared between adult mice with conditional gene ablation of skeletal myofiber VEGF (SkmVEGF-/-; n = 12) and littermate controls (n = 13). Diaphragm VEGF protein was ~50% lower in SkmVEGF-/- than littermate controls (1.45 ± 0.65 vs. 3.04 ± 1.41 pg/total protein; P = 0.001). This was accompanied by an ~15% impairment in maximal isometric specific force (F[1,23] = 15.01, P = 0.001) and a trend for improved fatigue resistance (P = 0.053). Mean fiber cross-sectional area and type I fiber cross-sectional area were lower in SkmVEGF-/- by ~40% and ~25% (P < 0.05). Capillary-to-fiber ratio was also lower in SkmVEGF-/- by ~40% (P < 0.05), and thus capillary density was not different. Sarcomeric actin expression was ~30% lower in SkmVEGF-/- (P < 0.05), whereas myosin heavy chain and MAFbx were similar (measured via immunoblot). Mitochondrial respiration, citrate synthase activity, PGC-1α, and hypoxia-inducible factor 1α were not different in SkmVEGF-/- (P > 0.05). However, mitochondrial-derived reactive oxygen species (ROS) flux was lower in SkmVEGF-/- (P = 0.0003). In conclusion, myofiber-specific VEGF gene deletion resulted in a lower capillary-to-fiber ratio, type I fiber atrophy, actin loss, and contractile dysfunction in the diaphragm. In contrast, mitochondrial respiratory function was preserved alongside lower ROS generation, which may play a compensatory role to preserve fatigue resistance in the diaphragm.NEW & NOTEWORTHY Diaphragm weakness is a hallmark of diseases in which oxygen delivery is compromised. Vascular endothelial growth factor (VEGF) modulates muscle perfusion; however, it remains unclear whether VEGF deficiency contributes to the onset of diaphragm dysfunction. Conditional skeletal myofiber VEGF gene ablation impaired diaphragm contractile function and resulted in type I fiber atrophy, a lower number of capillaries per fiber, and contractile protein content. Mitochondrial function was similar and reactive oxygen species flux was lower. Diaphragm VEGF deficiency may contribute to the onset of respiratory muscle weakness.
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Affiliation(s)
- Daniel T Cannon
- School of Exercise and Nutritional Sciences, San Diego State University, San Diego, California
| | - Lukas Rodewohl
- Department of Internal Medicine and Cardiology, Universität Leipzig Herzzentrum, Leipzig, Germany
| | - Volker Adams
- Department of Internal Medicine and Cardiology, Technische Universität Dresden, Dresden, Germany
| | - Ellen C Breen
- Department of Medicine, University of California, San Diego, California
| | - T Scott Bowen
- School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom
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28
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Meister J, Bone DBJ, Godlewski G, Liu Z, Lee RJ, Vishnivetskiy SA, Gurevich VV, Springer D, Kunos G, Wess J. Metabolic effects of skeletal muscle-specific deletion of beta-arrestin-1 and -2 in mice. PLoS Genet 2019; 15:e1008424. [PMID: 31622341 PMCID: PMC6818801 DOI: 10.1371/journal.pgen.1008424] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Revised: 10/29/2019] [Accepted: 09/16/2019] [Indexed: 01/01/2023] Open
Abstract
Type 2 diabetes (T2D) has become a major health problem worldwide. Skeletal muscle (SKM) is the key tissue for whole-body glucose disposal and utilization. New drugs aimed at improving insulin sensitivity of SKM would greatly expand available therapeutic options. β-arrestin-1 and -2 (Barr1 and Barr2, respectively) are two intracellular proteins best known for their ability to mediate the desensitization and internalization of G protein-coupled receptors (GPCRs). Recent studies suggest that Barr1 and Barr2 regulate several important metabolic functions including insulin release and hepatic glucose production. Since SKM expresses many GPCRs, including the metabolically important β2-adrenergic receptor, the goal of this study was to examine the potential roles of Barr1 and Barr2 in regulating SKM and whole-body glucose metabolism. Using SKM-specific knockout (KO) mouse lines, we showed that the loss of SKM Barr2, but not of SKM Barr1, resulted in mild improvements in glucose tolerance in diet-induced obese mice. SKM-specific Barr1- and Barr2-KO mice did not show any significant differences in exercise performance. However, lack of SKM Barr2 led to increased glycogen breakdown following a treadmill exercise challenge. Interestingly, mice that lacked both Barr1 and Barr2 in SKM showed no significant metabolic phenotypes. Thus, somewhat surprisingly, our data indicate that SKM β-arrestins play only rather subtle roles (SKM Barr2) in regulating whole-body glucose homeostasis and SKM insulin sensitivity.
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Affiliation(s)
- Jaroslawna Meister
- Molecular Signaling Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD, United States of America
- * E-mail: (JM); (JW)
| | - Derek B. J. Bone
- Molecular Signaling Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD, United States of America
| | - Grzegorz Godlewski
- Laboratory of Physiologic Studies, National Institute on Alcohol Abuse and Alcoholism, Bethesda, MD, United States of America
| | - Ziyi Liu
- Laboratory of Physiologic Studies, National Institute on Alcohol Abuse and Alcoholism, Bethesda, MD, United States of America
| | - Regina J. Lee
- Molecular Signaling Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD, United States of America
| | | | - Vsevolod V. Gurevich
- Department of Pharmacology, Vanderbilt University, Nashville, TN, United States of America
| | - Danielle Springer
- Murine Phenotyping Core, National Heart, Lung, and Blood Institute, Bethesda, MD, United States of America
| | - George Kunos
- Laboratory of Physiologic Studies, National Institute on Alcohol Abuse and Alcoholism, Bethesda, MD, United States of America
| | - Jürgen Wess
- Molecular Signaling Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD, United States of America
- * E-mail: (JM); (JW)
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29
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Caradu C, Guy A, James C, Reynaud A, Gadeau AP, Renault MA. Endogenous Sonic Hedgehog limits inflammation and angiogenesis in the ischaemic skeletal muscle of mice. Cardiovasc Res 2019; 114:759-770. [PMID: 29365079 DOI: 10.1093/cvr/cvy017] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2017] [Accepted: 01/19/2018] [Indexed: 12/23/2022] Open
Abstract
Aims Hedgehog (Hh) signalling has been shown to be re-activated in ischaemic tissues and participate in ischaemia-induced angiogenesis. Sonic Hedgehog (Shh) is upregulated by more than 80-fold in the ischaemic skeletal muscle, however its specific role in ischaemia-induced angiogenesis has not yet been fully investigated. The purpose of the present study was to investigate the role of endogenous Shh in ischaemia-induced angiogenesis. Methods and results To this aim, we used inducible Shh knock-out (KO) mice and unexpectedly found that capillary density was significantly increased in re-generating muscle of Shh deficient mice 5 days after hind limb ischaemia was induced, demonstrating that endogenous Shh does not promote angiogenesis but more likely limits it. Myosin and MyoD expression were equivalent in Shh deficient mice and control mice, indicating that endogenous Shh is not required for ischaemia-induced myogenesis. Additionally, we observed a significant increase in macrophage infiltration in the ischaemic muscle of Shh deficient mice. Our data indicate that this was due to an increase in chemokine expression by myoblasts in the setting of impaired Hh signalling, using tissue specific Smoothened conditional KO mice. The increased macrophage infiltration in mice deficient for Hh signalling in myocytes was associated with increased VEGFA expression and a transiently increased angiogenesis, demonstrating that Shh limits inflammation and angiogenesis indirectly by signalling to myocytes. Conclusion Although ectopic administration of Shh has previously been shown to promote ischaemia-induced angiogenesis, the present study reveals that endogenous Shh does not promote ischaemia-induced angiogenesis. On the contrary, the absence of Shh leads to aberrant ischaemic tissue inflammation and a transiently increased angiogenesis.
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Affiliation(s)
- Caroline Caradu
- Biology of Cardiovascular Diseases, Univ. Bordeaux, Inserm, CHU de Bordeaux, F-33604 Pessac, France
| | - Alexandre Guy
- Biology of Cardiovascular Diseases, Univ. Bordeaux, Inserm, CHU de Bordeaux, F-33604 Pessac, France
| | - Chloé James
- Biology of Cardiovascular Diseases, Univ. Bordeaux, Inserm, CHU de Bordeaux, F-33604 Pessac, France
| | - Annabel Reynaud
- Biology of Cardiovascular Diseases, Univ. Bordeaux, Inserm, CHU de Bordeaux, F-33604 Pessac, France
| | - Alain-Pierre Gadeau
- Biology of Cardiovascular Diseases, Univ. Bordeaux, Inserm, CHU de Bordeaux, F-33604 Pessac, France
| | - Marie-Ange Renault
- Biology of Cardiovascular Diseases, Univ. Bordeaux, Inserm, CHU de Bordeaux, F-33604 Pessac, France
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30
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Bone DBJ, Meister J, Knudsen JR, Dattaroy D, Cohen A, Lee R, Lu H, Metzger D, Jensen TE, Wess J. Skeletal Muscle-Specific Activation of G q Signaling Maintains Glucose Homeostasis. Diabetes 2019; 68:1341-1352. [PMID: 30936140 PMCID: PMC6610017 DOI: 10.2337/db18-0796] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Accepted: 03/22/2019] [Indexed: 12/19/2022]
Abstract
Skeletal muscle (SKM) insulin resistance plays a central role in the pathogenesis of type 2 diabetes. Because G-protein-coupled receptors (GPCRs) represent excellent drug targets, we hypothesized that activation of specific functional classes of SKM GPCRs might lead to improved glucose homeostasis in type 2 diabetes. At present, little is known about the in vivo metabolic roles of the various distinct GPCR signaling pathways operative in SKM. In this study, we tested the hypothesis that selective activation of SKM Gq signaling can improve SKM glucose uptake and whole-body glucose homeostasis under physiological and pathophysiological conditions. Studies with transgenic mice expressing a Gq-linked designer GPCR selectively in SKM cells demonstrated that receptor-mediated activation of SKM Gq signaling greatly promoted glucose uptake into SKM and significantly improved glucose homeostasis in obese, glucose-intolerant mice. These beneficial metabolic effects required the activity of SKM AMPK. In contrast, obese mutant mice that lacked both Gαq and Gα11 selectively in SKM showed severe deficits in glucose homeostasis. Moreover, GPCR-mediated activation of Gq signaling also stimulated glucose uptake in primary human SKM cells. Taken together, these findings strongly suggest that agents capable of enhancing SKM Gq signaling may prove useful as novel antidiabetic drugs.
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Affiliation(s)
- Derek B J Bone
- Molecular Signaling Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD
| | - Jaroslawna Meister
- Molecular Signaling Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD
| | - Jonas R Knudsen
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark
| | - Diptadip Dattaroy
- Molecular Signaling Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD
| | - Amanda Cohen
- Molecular Signaling Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD
| | - Regina Lee
- Molecular Signaling Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD
| | - Huiyan Lu
- Mouse Transgenic Core Facility, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD
| | - Daniel Metzger
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, CNRS UMR 7104, INSERM U1258, Université de Strasbourg, Illkirch, France
| | - Thomas E Jensen
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark
| | - Jürgen Wess
- Molecular Signaling Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD
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Djemai H, Hassani M, Daou N, Li Z, Sotiropoulos A, Noirez P, Coletti D. Srf KO and wild-type mice similarly adapt to endurance exercise. Eur J Transl Myol 2019; 29:8205. [PMID: 31354926 PMCID: PMC6615070 DOI: 10.4081/ejtm.2019.8205] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Accepted: 05/03/2019] [Indexed: 12/18/2022] Open
Abstract
Physical exercise has important effects as secondary prevention or intervention against several diseases. Endurance exercise induces local and global effects, resulting in skeletal muscle adaptations to aerobic activity and contributes to an amelioration of muscle performance. Furthermore, it prevents muscle loss. Serum response factor (Srf) is a transcription factor of pivotal importance for muscle tissues and animal models of Srf genetic deletion/over-expression are widely used to study Srf role in muscle homeostasis, physiology and pathology. A global characterisation of exercise adaptation in the absence of Srf has not been reported. We measured body composition, muscle force, running speed, energy expenditure and metabolism in WT and inducible skeletal muscle-specific Srf KO mice, following three weeks of voluntary exercise by wheel running. We found a major improvement in the aerobic capacity and muscle function in WT mice following exercise, as expected, and no major differences were observed in Srf KO mice as compared to WT mice, following exercise. Taken together, these observations suggest that Srf is not required for an early (within 3 weeks) adaptation to spontaneous exercise and that Srf KO mice behave similarly to the WT in terms of spontaneous physical activity and the resulting adaptive responses. Therefore, Srf KO mice can be used in functional muscle studies, without the results being affected by the lack of Srf. Since lack of Srf induces premature sarcopenia, our observations suggest that the modifications due to the absence of Srf take time to occur and that young, Srf KO mice behave similarly to WT in aerobic physical activities.
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Affiliation(s)
- Haidar Djemai
- Université Paris Descartes, Sorbonne Paris Cité, Paris, France.,IRMES, INSEP, Paris, France.,= equal contribution
| | - Medhi Hassani
- Sorbonne University, Paris, France.,Sapienza University of Rome, Rome, Italy.,Interuniversity Institute of Myology, Rome, Italy.,= equal contribution
| | | | | | - Athanassia Sotiropoulos
- Institut National de la Santé et de la Recherche Médicale U1016, Institut Cochin, Paris, France
| | - Philippe Noirez
- Université Paris Descartes, Sorbonne Paris Cité, Paris, France.,IRMES, INSEP, Paris, France.,Department of Exercise Science, UQAM, Montréal, Canada
| | - Dario Coletti
- Sorbonne University, Paris, France.,Sapienza University of Rome, Rome, Italy.,Interuniversity Institute of Myology, Rome, Italy
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Iwata M, Englund DA, Wen Y, Dungan CM, Murach KA, Vechetti IJ, Mobley CB, Peterson CA, McCarthy JJ. A novel tetracycline-responsive transgenic mouse strain for skeletal muscle-specific gene expression. Skelet Muscle 2018; 8:33. [PMID: 30368256 PMCID: PMC6204038 DOI: 10.1186/s13395-018-0181-y] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2018] [Accepted: 10/16/2018] [Indexed: 11/21/2022] Open
Abstract
Background The tetracycline-responsive system (Tet-ON/OFF) has proven to be a valuable tool for manipulating gene expression in an inducible, temporal, and tissue-specific manner. The purpose of this study was to create and characterize a new transgenic mouse strain utilizing the human skeletal muscle α-actin (HSA) promoter to drive skeletal muscle-specific expression of the reverse tetracycline transactivator (rtTA) gene which we have designated as the HSA-rtTA mouse. Methods To confirm the HSA-rtTA mouse was capable of driving skeletal muscle-specific expression, we crossed the HSA-rtTA mouse with the tetracycline-responsive histone H2B-green fluorescent protein (H2B-GFP) transgenic mouse in order to label myonuclei. Results Reverse transcription-PCR confirmed skeletal muscle-specific expression of rtTA mRNA, while single-fiber analysis showed highly effective GFP labeling of myonuclei in both fast- and slow-twitch skeletal muscles. Pax7 immunohistochemistry of skeletal muscle cross-sections revealed no appreciable GFP expression in satellite cells. Conclusions The HSA-rtTA transgenic mouse allows for robust, specific, and inducible gene expression across muscles of different fiber types. The HSA-rtTA mouse provides a powerful tool to manipulate gene expression in skeletal muscle.
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Affiliation(s)
- Masahiro Iwata
- The Center for Muscle Biology, University of Kentucky, Lexington, KY, 40536, USA.,Department of Physiology, College of Medicine, University of Kentucky, 800 Rose Street, Medical Science Building, Rm: MS-607A, Lexington, KY, 40536, USA.,Department of Rehabilitation, Faculty of Health Sciences, Nihon Fukushi University, 26-2 Higashihaemi-cho, Handa, 475-0012, Japan
| | - Davis A Englund
- The Center for Muscle Biology, University of Kentucky, Lexington, KY, 40536, USA.,Department of Rehabilitation Sciences, College of Health Sciences, University of Kentucky, Lexington, KY, 40536, USA
| | - Yuan Wen
- The Center for Muscle Biology, University of Kentucky, Lexington, KY, 40536, USA.,Department of Physiology, College of Medicine, University of Kentucky, 800 Rose Street, Medical Science Building, Rm: MS-607A, Lexington, KY, 40536, USA
| | - Cory M Dungan
- The Center for Muscle Biology, University of Kentucky, Lexington, KY, 40536, USA.,Department of Rehabilitation Sciences, College of Health Sciences, University of Kentucky, Lexington, KY, 40536, USA
| | - Kevin A Murach
- The Center for Muscle Biology, University of Kentucky, Lexington, KY, 40536, USA.,Department of Rehabilitation Sciences, College of Health Sciences, University of Kentucky, Lexington, KY, 40536, USA
| | - Ivan J Vechetti
- The Center for Muscle Biology, University of Kentucky, Lexington, KY, 40536, USA.,Department of Physiology, College of Medicine, University of Kentucky, 800 Rose Street, Medical Science Building, Rm: MS-607A, Lexington, KY, 40536, USA
| | - Christopher B Mobley
- The Center for Muscle Biology, University of Kentucky, Lexington, KY, 40536, USA.,Department of Physiology, College of Medicine, University of Kentucky, 800 Rose Street, Medical Science Building, Rm: MS-607A, Lexington, KY, 40536, USA
| | - Charlotte A Peterson
- The Center for Muscle Biology, University of Kentucky, Lexington, KY, 40536, USA.,Department of Rehabilitation Sciences, College of Health Sciences, University of Kentucky, Lexington, KY, 40536, USA
| | - John J McCarthy
- The Center for Muscle Biology, University of Kentucky, Lexington, KY, 40536, USA. .,Department of Physiology, College of Medicine, University of Kentucky, 800 Rose Street, Medical Science Building, Rm: MS-607A, Lexington, KY, 40536, USA.
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Gherardi G, Nogara L, Ciciliot S, Fadini GP, Blaauw B, Braghetta P, Bonaldo P, De Stefani D, Rizzuto R, Mammucari C. Loss of mitochondrial calcium uniporter rewires skeletal muscle metabolism and substrate preference. Cell Death Differ 2018; 26:362-381. [PMID: 30232375 DOI: 10.1038/s41418-018-0191-7] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Revised: 08/07/2018] [Accepted: 08/10/2018] [Indexed: 11/10/2022] Open
Abstract
Skeletal muscle mitochondria readily accumulate Ca2+ in response to SR store-releasing stimuli thanks to the activity of the mitochondrial calcium uniporter (MCU), the highly selective channel responsible for mitochondrial Ca2+ uptake. MCU positively regulates myofiber size in physiological conditions and counteracts pathological loss of muscle mass. Here we show that skeletal muscle-specific MCU deletion inhibits myofiber mitochondrial Ca2+ uptake, impairs muscle force and exercise performance, and determines a slow to fast switch in MHC expression. Mitochondrial Ca2+ uptake is required for effective glucose oxidation, as demonstrated by the fact that in muscle-specific MCU-/- myofibers oxidative metabolism is impaired and glycolysis rate is increased. Although defective, mitochondrial activity is partially sustained by increased fatty acid (FA) oxidation. In MCU-/- myofibers, PDP2 overexpression drastically reduces FA dependency, demonstrating that decreased PDH activity is the main trigger of the metabolic rewiring of MCU-/- muscles. Accordingly, PDK4 overexpression in MCUfl/fl myofibers is sufficient to increase FA-dependent respiration. Finally, as a result of the muscle-specific MCU deletion, a systemic catabolic response impinging on both liver and adipose tissue metabolism occurs.
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Affiliation(s)
- Gaia Gherardi
- Department of Biomedical Sciences, University of Padova, 35131, Padova, Italy
| | - Leonardo Nogara
- Department of Biomedical Sciences, University of Padova, 35131, Padova, Italy
| | - Stefano Ciciliot
- Department of Medicine, University of Padova, 35128, Padova, Italy.,Venetian Institute of Molecular Medicine, 35129, Padova, Italy
| | - Gian Paolo Fadini
- Department of Medicine, University of Padova, 35128, Padova, Italy.,Venetian Institute of Molecular Medicine, 35129, Padova, Italy
| | - Bert Blaauw
- Department of Biomedical Sciences, University of Padova, 35131, Padova, Italy.,Venetian Institute of Molecular Medicine, 35129, Padova, Italy
| | - Paola Braghetta
- Department of Molecular Medicine, University of Padova, 35131, Padova, Italy
| | - Paolo Bonaldo
- Department of Molecular Medicine, University of Padova, 35131, Padova, Italy
| | - Diego De Stefani
- Department of Biomedical Sciences, University of Padova, 35131, Padova, Italy
| | - Rosario Rizzuto
- Department of Biomedical Sciences, University of Padova, 35131, Padova, Italy.
| | - Cristina Mammucari
- Department of Biomedical Sciences, University of Padova, 35131, Padova, Italy.
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Monitoring disease activity noninvasively in the mdx model of Duchenne muscular dystrophy. Proc Natl Acad Sci U S A 2018; 115:7741-7746. [PMID: 29987034 DOI: 10.1073/pnas.1802425115] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Duchenne muscular dystrophy (DMD) is a rare, muscle degenerative disease resulting from the absence of the dystrophin protein. DMD is characterized by progressive loss of muscle fibers, muscle weakness, and eventually loss of ambulation and premature death. Currently, there is no cure for DMD and improved methods of disease monitoring are crucial for the development of novel treatments. In this study, we describe a new method of assessing disease progression noninvasively in the mdx model of DMD. The reporter mice, which we term the dystrophic Degeneration Reporter strains, contain an inducible CRE-responsive luciferase reporter active in mature myofibers. In these mice, muscle degeneration is reflected in changes in the level of luciferase expression, which can be monitored using noninvasive, bioluminescence imaging. We monitored the natural history and disease progression in these dystrophic report mice and found that decreases in luciferase signals directly correlated with muscle degeneration. We further demonstrated that this reporter strain, as well as a previously reported Regeneration Reporter strain, successfully reveals the effectiveness of a gene therapy treatment following systemic administration of a recombinant adeno-associated virus-6 (rAAV-6) encoding a microdystrophin construct. Our data demonstrate the value of these noninvasive imaging modalities for monitoring disease progression and response to therapy in mouse models of muscular dystrophy.
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Rich B, Scadeng M, Yamaguchi M, Wagner PD, Breen EC. Skeletal myofiber vascular endothelial growth factor is required for the exercise training-induced increase in dentate gyrus neuronal precursor cells. J Physiol 2017; 595:5931-5943. [PMID: 28597506 DOI: 10.1113/jp273994] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2016] [Accepted: 05/16/2017] [Indexed: 11/08/2022] Open
Abstract
KEY POINTS Peripheral vascular endothelial growth factor (VEGF) is necessary for exercise to stimulate hippocampal neurogenesis. Here we report that skeletal myofiber VEGF directly or indirectly regulates exercise-signalled proliferation of neuronal precursor cells. Our results found skeletal myofiber VEGF to be necessary for maintaining blood flow through hippocampal regions independent of exercise training state. This study demonstrates that skeletal myofiber VEGF is required for the hippocampal VEGF response to acute exercise. These results help to establish the mechanisms by which exercise, through skeletal myofiber VEGF, affects the hippocampus. ABSTRACT Exercise signals neurogenesis in the dentate gyrus of the hippocampus. This phenomenon requires vascular endothelial growth factor (VEGF) originating from outside the blood-brain barrier, but no cellular source has been identified. Thus, we hypothesized that VEGF produced by skeletal myofibers plays a role in regulating hippocampal neuronal precursor cell proliferation following exercise training. This was tested in adult conditional skeletal myofiber-specific VEGF gene-ablated mice (VEGFHSA-/- ) by providing VEGFHSA-/- and non-ablated (VEGFf/f ) littermates with running wheels for 14 days. Following this training period, hippocampal cerebral blood flow (CBF) was measured by functional magnetic resonance imaging (fMRI), and neuronal precursor cells (BrdU+/Nestin+) were detected by immunofluorescence. The VEGFf/f trained group showed improvements in both speed and endurance capacity in acute treadmill running tests (P < 0.05). The VEGFHSA-/- group did not. The number of proliferating neuronal precursor cells was increased with training in VEGFf/f (P < 0.05) but not in VEGFHSA-/- mice. Endothelial cell (CD31+) number did not change in this region with exercise training or skeletal myofiber VEGF gene deletion. However, resting blood flow through the hippocampal region was lower in VEGFHSA-/- mice, both untrained and trained, than untrained VEGFf/f mice (P < 0.05). An acute hypoxic challenge decreased CBF (P < 0.05) in untrained VEGFf/f , untrained VEGFHSA-/- and trained VEGFHSA-/- mice, but not trained VEGFf/f mice. VEGFf/f , but not VEGFHSA-/- , mice were able to acutely run on a treadmill at an intensity sufficient to increase hippocampus VEGF levels. These data suggest that VEGF expressed by skeletal myofibers may directly or indirectly regulate both hippocampal blood flow and neurogenesis.
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Affiliation(s)
- Benjamin Rich
- Department of Medicine, University of California, San Diego, La Jolla, CA, USA
| | - Miriam Scadeng
- Department of Radiology, University of California, San Diego, La Jolla, CA, USA
| | | | - Peter D Wagner
- Department of Medicine, University of California, San Diego, La Jolla, CA, USA
| | - Ellen C Breen
- Department of Medicine, University of California, San Diego, La Jolla, CA, USA
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36
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Goh Q, Millay DP. Requirement of myomaker-mediated stem cell fusion for skeletal muscle hypertrophy. eLife 2017; 6:20007. [PMID: 28186492 PMCID: PMC5338923 DOI: 10.7554/elife.20007] [Citation(s) in RCA: 96] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2016] [Accepted: 02/09/2017] [Indexed: 12/11/2022] Open
Abstract
Fusion of skeletal muscle stem/progenitor cells is required for proper development and regeneration, however the significance of this process during adult muscle hypertrophy has not been explored. In response to muscle overload after synergist ablation in mice, we show that myomaker, a muscle specific membrane protein essential for myoblast fusion, is activated mainly in muscle progenitors and not myofibers. We rendered muscle progenitors fusion-incompetent through genetic deletion of myomaker in muscle stem cells and observed a complete reduction of overload-induced hypertrophy. This blunted hypertrophic response was associated with a reduction in Akt and p70s6k signaling and protein synthesis, suggesting a link between myonuclear accretion and activation of pro-hypertrophic pathways. Furthermore, fusion-incompetent muscle exhibited increased fibrosis after muscle overload, indicating a protective role for normal stem cell activity in reducing myofiber strain associated with hypertrophy. These findings reveal an essential contribution of myomaker-mediated stem cell fusion during physiological adult muscle hypertrophy.
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Affiliation(s)
- Qingnian Goh
- Department of Molecular Cardiovascular Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, United States
| | - Douglas P Millay
- Department of Molecular Cardiovascular Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, United States
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Joshi S, Davidson G, Le Gras S, Watanabe S, Braun T, Mengus G, Davidson I. TEAD transcription factors are required for normal primary myoblast differentiation in vitro and muscle regeneration in vivo. PLoS Genet 2017; 13:e1006600. [PMID: 28178271 PMCID: PMC5323021 DOI: 10.1371/journal.pgen.1006600] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Revised: 02/23/2017] [Accepted: 01/24/2017] [Indexed: 12/22/2022] Open
Abstract
The TEAD family of transcription factors (TEAD1-4) bind the MCAT element in the regulatory elements of both growth promoting and myogenic differentiation genes. Defining TEAD transcription factor function in myogenesis has proved elusive due to overlapping expression of family members and their functional redundancy. We show that silencing of either Tead1, Tead2 or Tead4 did not effect primary myoblast (PM) differentiation, but that their simultaneous knockdown strongly impaired differentiation. In contrast, Tead1 or Tead4 silencing impaired C2C12 differentiation showing their different contributions in PMs and C2C12 cells. Chromatin immunoprecipitation identified enhancers associated with myogenic genes bound by combinations of Tead4, Myod1 or Myog. Tead4 regulated distinct gene sets in C2C12 cells and PMs involving both activation of the myogenic program and repression of growth and signaling pathways. ChIP-seq from mature mouse muscle fibres in vivo identified a set of highly transcribed muscle cell-identity genes and sites bound by Tead1 and Tead4. Although inactivation of Tead4 in mature muscle fibres caused no obvious phenotype under normal conditions, notexin-induced muscle regeneration was delayed in Tead4 mutants suggesting an important role in myogenic differentiation in vivo. By combining knockdown in cell models in vitro with Tead4 inactivation in muscle in vivo, we provide the first comprehensive description of the specific and redundant roles of Tead factors in myogenic differentiation.
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Affiliation(s)
- Shilpy Joshi
- Department of Functional Genomics and Cancer, Institut de Génétique et de Biologie Moléculaire et Cellulaire, CNRS/INSERM/UNISTRA, Illkirch, France
| | - Guillaume Davidson
- Department of Functional Genomics and Cancer, Institut de Génétique et de Biologie Moléculaire et Cellulaire, CNRS/INSERM/UNISTRA, Illkirch, France
| | - Stéphanie Le Gras
- Department of Functional Genomics and Cancer, Institut de Génétique et de Biologie Moléculaire et Cellulaire, CNRS/INSERM/UNISTRA, Illkirch, France
| | - Shuichi Watanabe
- Department of Cardiac Development and Remodeling, Max-Planck-Institute for Heart and Lung Research, Ludwigstrasse, Bad Nauheim, Germany
| | - Thomas Braun
- Department of Cardiac Development and Remodeling, Max-Planck-Institute for Heart and Lung Research, Ludwigstrasse, Bad Nauheim, Germany
| | - Gabrielle Mengus
- Department of Functional Genomics and Cancer, Institut de Génétique et de Biologie Moléculaire et Cellulaire, CNRS/INSERM/UNISTRA, Illkirch, France
| | - Irwin Davidson
- Department of Functional Genomics and Cancer, Institut de Génétique et de Biologie Moléculaire et Cellulaire, CNRS/INSERM/UNISTRA, Illkirch, France
- * E-mail:
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38
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Cheng LH, Hung KF, Lee TC, Huang CY, Chiu WT, Lo JF, Huang TF. Mitochondrial co-chaperone protein Tid1 is required for energy homeostasis during skeletal myogenesis. Stem Cell Res Ther 2016; 7:185. [PMID: 27927223 PMCID: PMC5143475 DOI: 10.1186/s13287-016-0443-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2016] [Revised: 11/01/2016] [Accepted: 11/17/2016] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Tid1 is a mitochondrial co-chaperone protein and its transcript is abundantly expressed in skeletal muscle tissues. However, the physiological function of Tid1 during skeletal myogenesis remains unclear. METHODS In vitro induced differentiation assay of mouse myoblast C2C12 cells was applied to examine the physiological role of Tid1 during skeletal myogenesis. In addition, transgenic mice with muscle specific (HSA-Cre) Tid1 deletion were established and examined to determine the physiological function of Tid1 during skeletal muscle development in vivo. RESULTS Expression of Tid1 protein was upregulated in the differentiated C2C12 cells, and the HSA-Tid1f/f mice displayed muscular dystrophic phenotype. The expression of myosin heavy chain (MyHC), the protein served as the muscular development marker, was reduced in HSA-Tid1f/f mice at postnatal day (P)5 and P8. The protein levels of ATP sensor (p-AMPK) and mitochondrial biogenesis protein (PGC-1α) were also significantly reduced in HSA-Tid1f/f mice. Moreover, Tid1 deficiency induced apoptotic marker Caspase-3 in muscle tissues of HSA-Tid1f/f mice. Consistent with the in vivo finding, we observed that downregulation of Tid1 not only reduced the ATP production but also abolished the differentiation ability of C2C12 cells by impairing the mitochondrial activity. CONCLUSION Together, our results suggest that Tid1 deficiency reduces ATP production and abolishes mitochondrial activity, resulting in energy imbalance and promoting apoptosis of muscle cells during myogenesis. It will be of importance to understand the function of Tid1 during human muscular dystrophy in the future.
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Affiliation(s)
- Li-Hao Cheng
- Institute of Oral Biology, National Yang-Ming University, Taipei, Taiwan, Republic of China
| | - Kai-Feng Hung
- Department of Dentistry, School of Dentistry, National Yang-Ming University, Taipei, Taiwan, Republic of China
| | - Te-Chang Lee
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan, Republic of China
| | - Chih-Yang Huang
- Graduate Institute of Chinese Medical Science and Institute of Medical Science, China Medical University, Taichung, Taiwan, Republic of China.,Institute of Basic Medical Science, China Medical University, Taichung, Taiwan, Republic of China.,Department of Health and Nutrition Biotechnology, Asia University, Taichung, Taiwan, Republic of China
| | - Wen-Ting Chiu
- Institute of Oral Biology, National Yang-Ming University, Taipei, Taiwan, Republic of China
| | - Jeng-Fan Lo
- Institute of Oral Biology, National Yang-Ming University, Taipei, Taiwan, Republic of China. .,Department of Dentistry, School of Dentistry, National Yang-Ming University, Taipei, Taiwan, Republic of China. .,Graduate Institute of Chinese Medical Science and Institute of Medical Science, China Medical University, Taichung, Taiwan, Republic of China. .,Department of Dentistry, Taipei Veterans General Hospital, Taipei, Taiwan, Republic of China. .,Genome Research Center, National Yang-Ming University, Taipei, Taiwan, Republic of China. .,National Yang-Ming University VGH Genome Research Center, Taipei, Taiwan, Republic of China.
| | - Tung-Fu Huang
- School of Medicine, National Yang-Ming University, Taipei, Taiwan, Republic of China. .,Department of Orthopedics and Traumatology, Taipei Veterans General Hospital, Taipei, Taiwan, Republic of China.
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39
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Sakakibara I, Wurmser M, Dos Santos M, Santolini M, Ducommun S, Davaze R, Guernec A, Sakamoto K, Maire P. Six1 homeoprotein drives myofiber type IIA specialization in soleus muscle. Skelet Muscle 2016; 6:30. [PMID: 27597886 PMCID: PMC5011358 DOI: 10.1186/s13395-016-0102-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2016] [Accepted: 08/16/2016] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Adult skeletal muscles are composed of slow and fast myofiber subtypes which each express selective genes required for their specific contractile and metabolic activity. Six homeoproteins are transcription factors regulating muscle cell fate through activation of myogenic regulatory factors and driving fast-type gene expression during embryogenesis. RESULTS We show here that Six1 protein accumulates more robustly in the nuclei of adult fast-type muscles than in adult slow-type muscles, this specific enrichment takes place during perinatal growth. Deletion of Six1 in soleus impaired fast-type myofiber specialization during perinatal development, resulting in a slow phenotype and a complete lack of Myosin heavy chain 2A (MyHCIIA) expression. Global transcriptomic analysis of wild-type and Six1 mutant myofibers identified the gene networks controlled by Six1 in adult soleus muscle. This analysis showed that Six1 is required for the expression of numerous genes encoding fast-type sarcomeric proteins, glycolytic enzymes and controlling intracellular calcium homeostasis. Parvalbumin, a key player of calcium buffering, in particular, is a direct target of Six1 in the adult myofiber. CONCLUSIONS This analysis revealed that Six1 controls distinct aspects of adult muscle physiology in vivo, and acts as a main determinant of fast-fiber type acquisition and maintenance.
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Affiliation(s)
- Iori Sakakibara
- INSERM U1016, Institut Cochin, Paris, 75014 France
- CNRS UMR 8104, Paris, 75014 France
- Université Paris Descartes, Sorbonne Paris Cité, Paris, 75014 France
- Division of Integrative Pathophysiology, Proteo-Science Center, Graduate School of Medicine, Ehime University, Ehime, Japan
| | - Maud Wurmser
- INSERM U1016, Institut Cochin, Paris, 75014 France
- CNRS UMR 8104, Paris, 75014 France
- Université Paris Descartes, Sorbonne Paris Cité, Paris, 75014 France
| | - Matthieu Dos Santos
- INSERM U1016, Institut Cochin, Paris, 75014 France
- CNRS UMR 8104, Paris, 75014 France
- Université Paris Descartes, Sorbonne Paris Cité, Paris, 75014 France
| | - Marc Santolini
- Laboratoire de Physique Statistique, CNRS, Université P. et M. Curie, Université D. Diderot, École Normale Supérieure, Paris, 75005 France
| | - Serge Ducommun
- Nestlé Institute of Health Sciences SA, EPFL Innovation Park, Lausanne, Switzerland
| | - Romain Davaze
- INSERM U1016, Institut Cochin, Paris, 75014 France
- CNRS UMR 8104, Paris, 75014 France
- Université Paris Descartes, Sorbonne Paris Cité, Paris, 75014 France
| | - Anthony Guernec
- INSERM U1016, Institut Cochin, Paris, 75014 France
- CNRS UMR 8104, Paris, 75014 France
- Université Paris Descartes, Sorbonne Paris Cité, Paris, 75014 France
| | - Kei Sakamoto
- Nestlé Institute of Health Sciences SA, EPFL Innovation Park, Lausanne, Switzerland
| | - Pascal Maire
- INSERM U1016, Institut Cochin, Paris, 75014 France
- CNRS UMR 8104, Paris, 75014 France
- Université Paris Descartes, Sorbonne Paris Cité, Paris, 75014 France
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40
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Vavrova E, Lenoir V, Alves-Guerra MC, Denis RG, Castel J, Esnous C, Dyck JRB, Luquet S, Metzger D, Bouillaud F, Prip-Buus C. Muscle expression of a malonyl-CoA-insensitive carnitine palmitoyltransferase-1 protects mice against high-fat/high-sucrose diet-induced insulin resistance. Am J Physiol Endocrinol Metab 2016; 311:E649-60. [PMID: 27507552 DOI: 10.1152/ajpendo.00020.2016] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Accepted: 08/09/2016] [Indexed: 12/17/2022]
Abstract
Impaired skeletal muscle mitochondrial fatty acid oxidation (mFAO) has been implicated in the etiology of insulin resistance. Carnitine palmitoyltransferase-1 (CPT1) is a key regulatory enzyme of mFAO whose activity is inhibited by malonyl-CoA, a lipogenic intermediate. Whereas increasing CPT1 activity in vitro has been shown to exert a protective effect against lipid-induced insulin resistance in skeletal muscle cells, only a few studies have addressed this issue in vivo. We thus examined whether a direct modulation of muscle CPT1/malonyl-CoA partnership is detrimental or beneficial for insulin sensitivity in the context of diet-induced obesity. By using a Cre-LoxP recombination approach, we generated mice with skeletal muscle-specific and inducible expression of a mutated CPT1 form (CPT1mt) that is active but insensitive to malonyl-CoA inhibition. When fed control chow, homozygous CPT1mt transgenic (dbTg) mice exhibited decreased CPT1 sensitivity to malonyl-CoA inhibition in isolated muscle mitochondria, which was sufficient to substantially increase ex vivo muscle mFAO capacity and whole body fatty acid utilization in vivo. Moreover, dbTg mice were less prone to high-fat/high-sucrose (HFHS) diet-induced insulin resistance and muscle lipotoxicity despite similar body weight gain, adiposity, and muscle malonyl-CoA content. Interestingly, these CPT1mt-protective effects in dbTg-HFHS mice were associated with preserved muscle insulin signaling, increased muscle glycogen content, and upregulation of key genes involved in muscle glucose metabolism. These beneficial effects of muscle CPT1mt expression suggest that a direct modulation of the malonyl-CoA/CPT1 partnership in skeletal muscle could represent a potential strategy to prevent obesity-induced insulin resistance.
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Affiliation(s)
- Eliska Vavrova
- Institut National de la Santé et de la Recherche Médicale, U1016, Institut Cochin, Paris, France; Centre National de la Recherche Scientifique, UMR8104, Paris, France; Université Paris Descartes, Sorbonne Paris Cité, Paris, France; Université Paris Diderot, Paris, France
| | - Véronique Lenoir
- Institut National de la Santé et de la Recherche Médicale, U1016, Institut Cochin, Paris, France; Centre National de la Recherche Scientifique, UMR8104, Paris, France; Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Marie-Clotilde Alves-Guerra
- Institut National de la Santé et de la Recherche Médicale, U1016, Institut Cochin, Paris, France; Centre National de la Recherche Scientifique, UMR8104, Paris, France; Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Raphaël G Denis
- Université Paris Diderot, Sorbonne Paris Cité, Unité de Biologie Fonctionnelle et Adaptative, Centre National de la Recherche Scientifique UMR8251, Paris, France
| | - Julien Castel
- Université Paris Diderot, Sorbonne Paris Cité, Unité de Biologie Fonctionnelle et Adaptative, Centre National de la Recherche Scientifique UMR8251, Paris, France
| | - Catherine Esnous
- Institut National de la Santé et de la Recherche Médicale, U1016, Institut Cochin, Paris, France; Centre National de la Recherche Scientifique, UMR8104, Paris, France; Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Jason R B Dyck
- Cardiovascular Research Centre, Department of Pediatrics, University of Alberta, Edmonton, Alberta, Canada
| | - Serge Luquet
- Université Paris Diderot, Sorbonne Paris Cité, Unité de Biologie Fonctionnelle et Adaptative, Centre National de la Recherche Scientifique UMR8251, Paris, France
| | - Daniel Metzger
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Institut National de la Santé et de la Recherche Médicale, U964, Centre National de la Recherche Scientifique, UMR7104, Université de Strasbourg, Illkirch, France
| | - Frédéric Bouillaud
- Institut National de la Santé et de la Recherche Médicale, U1016, Institut Cochin, Paris, France; Centre National de la Recherche Scientifique, UMR8104, Paris, France; Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Carina Prip-Buus
- Institut National de la Santé et de la Recherche Médicale, U1016, Institut Cochin, Paris, France; Centre National de la Recherche Scientifique, UMR8104, Paris, France; Université Paris Descartes, Sorbonne Paris Cité, Paris, France;
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O'Neill BT, Lee KY, Klaus K, Softic S, Krumpoch MT, Fentz J, Stanford KI, Robinson MM, Cai W, Kleinridders A, Pereira RO, Hirshman MF, Abel ED, Accili D, Goodyear LJ, Nair KS, Kahn CR. Insulin and IGF-1 receptors regulate FoxO-mediated signaling in muscle proteostasis. J Clin Invest 2016; 126:3433-46. [PMID: 27525440 DOI: 10.1172/jci86522] [Citation(s) in RCA: 111] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2016] [Accepted: 06/23/2016] [Indexed: 12/20/2022] Open
Abstract
Diabetes strongly impacts protein metabolism, particularly in skeletal muscle. Insulin and IGF-1 enhance muscle protein synthesis through their receptors, but the relative roles of each in muscle proteostasis have not been fully elucidated. Using mice with muscle-specific deletion of the insulin receptor (M-IR-/- mice), the IGF-1 receptor (M-IGF1R-/- mice), or both (MIGIRKO mice), we assessed the relative contributions of IR and IGF1R signaling to muscle proteostasis. In differentiated muscle, IR expression predominated over IGF1R expression, and correspondingly, M-IR-/- mice displayed a moderate reduction in muscle mass whereas M-IGF1R-/- mice did not. However, these receptors serve complementary roles, such that double-knockout MIGIRKO mice displayed a marked reduction in muscle mass that was linked to increases in proteasomal and autophagy-lysosomal degradation, accompanied by a high-protein-turnover state. Combined muscle-specific deletion of FoxO1, FoxO3, and FoxO4 in MIGIRKO mice reversed increased autophagy and completely rescued muscle mass without changing proteasomal activity. These data indicate that signaling via IR is more important than IGF1R in controlling proteostasis in differentiated muscle. Nonetheless, the overlap of IR and IGF1R signaling is critical to the regulation of muscle protein turnover, and this regulation depends on suppression of FoxO-regulated, autophagy-mediated protein degradation.
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Schroder E, Hodge B, Riley L, Zhang X, Esser K. Reply from Elizabeth Schroder, Brian Hodge, Lance Riley, Xiping Zhang and Karyn Esser. J Physiol 2016; 594:3163-4. [DOI: 10.1113/jp272165] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2016] [Accepted: 01/29/2016] [Indexed: 11/08/2022] Open
Affiliation(s)
- Elizabeth Schroder
- Center for Muscle Biology and Department of Physiology; College of Medicine, University of Kentucky; Lexington KY USA
| | - Brian Hodge
- Center for Muscle Biology and Department of Physiology; College of Medicine, University of Kentucky; Lexington KY USA
| | - Lance Riley
- Center for Muscle Biology and Department of Physiology; College of Medicine, University of Kentucky; Lexington KY USA
| | - Xiping Zhang
- Center for Muscle Biology and Department of Physiology; College of Medicine, University of Kentucky; Lexington KY USA
| | - Karyn Esser
- Center for Muscle Biology and Department of Physiology; College of Medicine, University of Kentucky; Lexington KY USA
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Knapp AE, Goldberg D, Delavar H, Trisko BM, Tang K, Hogan MC, Wagner PD, Breen EC. Skeletal myofiber VEGF regulates contraction-induced perfusion and exercise capacity but not muscle capillarity in adult mice. Am J Physiol Regul Integr Comp Physiol 2016; 311:R192-9. [PMID: 27225953 DOI: 10.1152/ajpregu.00533.2015] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Accepted: 05/17/2016] [Indexed: 11/22/2022]
Abstract
A single bout of exhaustive exercise signals expression of vascular endothelial growth factor (VEGF) in the exercising muscle. Previous studies have reported that mice with life-long deletion of skeletal myofiber VEGF have fewer capillaries and a severe reduction in endurance exercise. However, in adult mice, VEGF gene deletion conditionally targeted to skeletal myofibers limits exercise capacity without evidence of capillary regression. To explain this, we hypothesized that adult skeletal myofiber VEGF acutely regulates skeletal muscle perfusion during muscle contraction. A tamoxifen-inducible skeletal myofiber-specific VEGF gene deletion mouse (skmVEGF-/-) was used to reduce skeletal muscle VEGF protein by 90% in adult mice. Three weeks after inducing deletion of the skeletal myofiber VEGF gene, skmVEGF-/- mice exhibited diminished maximum running speed (-10%, P < 0.05) and endurance capacity (-47%; P < 0.05), which did not persist after 8 wk. In skmVEGF-/- mice, gastrocnemius complex time to fatigue measured in situ was 71% lower than control mice. Contraction-induced perfusion measured by optical imaging during a period of electrically stimulated muscle contraction was 85% lower in skmVEGF-/- than control mice. No evidence of capillary rarefication was detected in the soleus, gastrocnemius, and extensor digitorum longus (EDL) up to 8 wk after tamoxifen-induced VEGF ablation, and contractility and fatigue resistance of the soleus measured ex vivo were also unchanged. The force-frequency of the EDL showed a small right shift, but fatigue resistance did not differ between EDL from control and skmVEGF-/- mice. These data suggest myofiber VEGF is required for regulating perfusion during periods of contraction and may in this manner affect endurance capacity.
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Affiliation(s)
- Amy E Knapp
- Department of Medicine, University of California, San Diego, La Jolla, California
| | - Daniel Goldberg
- Department of Medicine, University of California, San Diego, La Jolla, California
| | - Hamid Delavar
- Department of Medicine, University of California, San Diego, La Jolla, California
| | - Breanna M Trisko
- Department of Medicine, University of California, San Diego, La Jolla, California
| | - Kechun Tang
- Department of Medicine, University of California, San Diego, La Jolla, California
| | - Michael C Hogan
- Department of Medicine, University of California, San Diego, La Jolla, California
| | - Peter D Wagner
- Department of Medicine, University of California, San Diego, La Jolla, California
| | - Ellen C Breen
- Department of Medicine, University of California, San Diego, La Jolla, California
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Olenchock BA, Moslehi J, Baik AH, Davidson SM, Williams J, Gibson WJ, Chakraborty AA, Pierce KA, Miller CM, Hanse EA, Kelekar A, Sullivan LB, Wagers AJ, Clish CB, Vander Heiden MG, Kaelin WG. EGLN1 Inhibition and Rerouting of α-Ketoglutarate Suffice for Remote Ischemic Protection. Cell 2016; 164:884-95. [PMID: 26919427 PMCID: PMC4819986 DOI: 10.1016/j.cell.2016.02.006] [Citation(s) in RCA: 99] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2015] [Revised: 12/12/2015] [Accepted: 02/01/2016] [Indexed: 12/30/2022]
Abstract
Ischemic preconditioning is the phenomenon whereby brief periods of sublethal ischemia protect against a subsequent, more prolonged, ischemic insult. In remote ischemic preconditioning (RIPC), ischemia to one organ protects others organs at a distance. We created mouse models to ask if inhibition of the alpha-ketoglutarate (αKG)-dependent dioxygenase Egln1, which senses oxygen and regulates the hypoxia-inducible factor (HIF) transcription factor, could suffice to mediate local and remote ischemic preconditioning. Using somatic gene deletion and a pharmacological inhibitor, we found that inhibiting Egln1 systemically or in skeletal muscles protects mice against myocardial ischemia-reperfusion (I/R) injury. Parabiosis experiments confirmed that RIPC in this latter model was mediated by a secreted factor. Egln1 loss causes accumulation of circulating αKG, which drives hepatic production and secretion of kynurenic acid (KYNA) that is necessary and sufficient to mediate cardiac ischemic protection in this setting.
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Affiliation(s)
- Benjamin A Olenchock
- Division of Cardiovascular Medicine, Department of Medicine, The Brigham and Women's Hospital, Boston, MA 02115, USA; Harvard Medical School, Boston, MA 02115, USA; Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Javid Moslehi
- Division of Cardiovascular Medicine, Department of Medicine, Vanderbilt School of Medicine, Nashville, TN 37235, USA
| | - Alan H Baik
- Department of Medicine, University of California, San Francisco, San Francisco, CA 94117, USA
| | - Shawn M Davidson
- Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Jeremy Williams
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA 02215, USA
| | - William J Gibson
- Harvard Medical School, Boston, MA 02115, USA; Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA 02215, USA
| | | | - Kerry A Pierce
- Metabolomics Platform, Broad Institute, Cambridge, MA 02142, USA
| | - Christine M Miller
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA 02138, USA; Joslin Diabetes Center, Boston, MA 02215, USA
| | - Eric A Hanse
- Department of Laboratory Medicine and Pathology and Masonic Cancer Center, University of Minnesota, Minneapolis, MN 55455, USA
| | - Ameeta Kelekar
- Department of Laboratory Medicine and Pathology and Masonic Cancer Center, University of Minnesota, Minneapolis, MN 55455, USA
| | - Lucas B Sullivan
- Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Amy J Wagers
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA 02138, USA; Joslin Diabetes Center, Boston, MA 02215, USA
| | - Clary B Clish
- Metabolomics Platform, Broad Institute, Cambridge, MA 02142, USA
| | - Matthew G Vander Heiden
- Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA 02215, USA
| | - William G Kaelin
- Harvard Medical School, Boston, MA 02115, USA; Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA 02215, USA; Howard Hughes Medical Institute, Chevy Chase, MD 20815, USA.
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45
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The transcriptional coregulator PGC-1β controls mitochondrial function and anti-oxidant defence in skeletal muscles. Nat Commun 2015; 6:10210. [PMID: 26674215 PMCID: PMC4703903 DOI: 10.1038/ncomms10210] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2015] [Accepted: 11/16/2015] [Indexed: 12/31/2022] Open
Abstract
The transcriptional coregulators PGC-1α and PGC-1β modulate the expression of numerous partially overlapping genes involved in mitochondrial biogenesis and energetic metabolism. The physiological role of PGC-1β is poorly understood in skeletal muscle, a tissue of high mitochondrial content to produce ATP levels required for sustained contractions. Here we determine the physiological role of PGC-1β in skeletal muscle using mice, in which PGC-1β is selectively ablated in skeletal myofibres at adulthood (PGC-1β((i)skm-/-) mice). We show that myofibre myosin heavy chain composition and mitochondrial number, muscle strength and glucose homeostasis are unaffected in PGC-1β((i)skm-/-) mice. However, decreased expression of genes controlling mitochondrial protein import, translational machinery and energy metabolism in PGC-1β((i)skm-/-) muscles leads to mitochondrial structural and functional abnormalities, impaired muscle oxidative capacity and reduced exercise performance. Moreover, enhanced free-radical leak and reduced expression of the mitochondrial anti-oxidant enzyme Sod2 increase muscle oxidative stress. PGC-1β is therefore instrumental for skeletal muscles to cope with high energetic demands.
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46
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Huey KA, Smith SA, Sulaeman A, Breen EC. Skeletal myofiber VEGF is necessary for myogenic and contractile adaptations to functional overload of the plantaris in adult mice. J Appl Physiol (1985) 2015; 120:188-95. [PMID: 26542520 DOI: 10.1152/japplphysiol.00638.2015] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2015] [Accepted: 10/21/2015] [Indexed: 12/31/2022] Open
Abstract
The ability to enhance muscle size and function is important for overall health. In this study, skeletal myofiber vascular endothelial growth factor (VEGF) was hypothesized to regulate hypertrophy, capillarity, and contractile function in response to functional overload (FO). Adult myofiber-specific VEGF gene-ablated mice (skmVEGF(-/-)) and wild-type (WT) littermates underwent plantaris FO or sham surgery (SHAM). Mass, morphology, in vivo function, IGF-1, basic fibroblast growth factor (bFGF), hepatocyte growth factor (HGF), and Akt were measured at 7, 14, and 30 days. FO resulted in hypertrophy in both genotypes, but fiber sizes were 13% and 23% smaller after 14 and 30 days, respectively, and mass 15% less after 30 days in skmVEGF(-/-) than WT. FO increased isometric force after 30 days in WT and decreased in skmVEGF(-/-) after 7 and 14 days. FO also resulted in a reduction in specific force and this differed between genotypes at 14 days. Fatigue resistance improved only in 14-day WT mice. Capillary density was decreased by FO in both genotypes. However, capillary-to-fiber ratios were 19% and 15% lower in skmVEGF(-/-) than WT at the 14- and 30-day time points, respectively. IGF-1 was increased by FO at all time points and was 45% and 40% greater in skmVEGF(-/-) than WT after 7 and 14 days, respectively. bFGF, HGF, total Akt, and phospho-Akt, independent of VEGF expression, and VEGF levels in WT were increased after 7 days of FO. These findings suggest VEGF-dependent capillary maintenance supports muscle growth and function in overloaded muscle and is not rescued by compensatory IGF-1 expression.
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Affiliation(s)
- Kimberly A Huey
- College of Pharmacy and Health Sciences, Drake University, Des Moines, Iowa; and
| | - Sophia A Smith
- College of Pharmacy and Health Sciences, Drake University, Des Moines, Iowa; and
| | - Alexis Sulaeman
- Department of Medicine, University of California-San Diego, La Jolla, California
| | - Ellen C Breen
- Department of Medicine, University of California-San Diego, La Jolla, California
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Tsai S, Sitzmann JM, Dastidar SG, Rodriguez AA, Vu SL, McDonald CE, Academia EC, O'Leary MN, Ashe TD, La Spada AR, Kennedy BK. Muscle-specific 4E-BP1 signaling activation improves metabolic parameters during aging and obesity. J Clin Invest 2015; 125:2952-64. [PMID: 26121750 DOI: 10.1172/jci77361] [Citation(s) in RCA: 90] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2014] [Accepted: 05/26/2015] [Indexed: 12/22/2022] Open
Abstract
Eukaryotic translation initiation factor 4E-binding protein 1 (4E-BP1) is a key downstream effector of mTOR complex 1 (mTORC1) that represses cap-dependent mRNA translation initiation by sequestering the translation initiation factor eIF4E. Reduced mTORC1 signaling is associated with life span extension and improved metabolic homeostasis, yet the downstream targets that mediate these benefits are unclear. Here, we demonstrated that enhanced 4E-BP1 activity in mouse skeletal muscle protects against age- and diet-induced insulin resistance and metabolic rate decline. Transgenic animals displayed increased energy expenditure; altered adipose tissue distribution, including reduced white adipose accumulation and preserved brown adipose mass; and were protected from hepatic steatosis. Skeletal muscle-specific 4E-BP1 mediated metabolic protection directly through increased translation of peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α) and enhanced respiratory function. Non-cell autonomous protection was through preservation of brown adipose tissue metabolism, which was increased in 4E-BP1 transgenic animals during normal aging and in a response to diet-induced type 2 diabetes. Adipose phenotypes may derive from enhanced skeletal muscle expression and secretion of the known myokine FGF21. Unlike skeletal muscle, enhanced adipose-specific 4E-BP1 activity was not protective but instead was deleterious in response to the same challenges. These findings indicate that regulation of 4E-BP1 in skeletal muscle may serve as an important conduit through which mTORC1 controls metabolism.
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48
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Milan G, Romanello V, Pescatore F, Armani A, Paik JH, Frasson L, Seydel A, Zhao J, Abraham R, Goldberg AL, Blaauw B, DePinho RA, Sandri M. Regulation of autophagy and the ubiquitin-proteasome system by the FoxO transcriptional network during muscle atrophy. Nat Commun 2015; 6:6670. [PMID: 25858807 PMCID: PMC4403316 DOI: 10.1038/ncomms7670] [Citation(s) in RCA: 462] [Impact Index Per Article: 51.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2014] [Accepted: 02/18/2015] [Indexed: 12/19/2022] Open
Abstract
Stresses like low nutrients, systemic inflammation, cancer or infections provoke a catabolic state characterized by enhanced muscle proteolysis and amino acid release to sustain liver gluconeogenesis and tissue protein synthesis. These conditions activate the family of Forkhead Box (Fox) O transcription factors. Here we report that muscle-specific deletion of FoxO members protects from muscle loss as a result of the role of FoxOs in the induction of autophagy–lysosome and ubiquitin–proteasome systems. Notably, in the setting of low nutrient signalling, we demonstrate that FoxOs are required for Akt activity but not for mTOR signalling. FoxOs control several stress–response pathways such as the unfolded protein response, ROS detoxification, DNA repair and translation. Finally, we identify FoxO-dependent ubiquitin ligases including MUSA1 and a previously uncharacterised ligase termed SMART (Specific of Muscle Atrophy and Regulated by Transcription). Our findings underscore the central function of FoxOs in coordinating a variety of stress-response genes during catabolic conditions. FoxO transcription factors promote muscle atrophy in response to stresses such as low nutrient availability. By generating muscle-specific FoxO triple-knockout mice, Milan et al. identify mechanisms by which the FoxO transcriptional network coordinates autophagic and proteasomal protein degradation.
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Affiliation(s)
- Giulia Milan
- Venetian Institute of Molecular Medicine, via Orus 2, 35129 Padova, Italy
| | - Vanina Romanello
- Venetian Institute of Molecular Medicine, via Orus 2, 35129 Padova, Italy
| | - Francesca Pescatore
- 1] Venetian Institute of Molecular Medicine, via Orus 2, 35129 Padova, Italy [2] Department of Biomedical Sciences, University of Padova, 35131 Padova, Italy
| | - Andrea Armani
- Venetian Institute of Molecular Medicine, via Orus 2, 35129 Padova, Italy
| | - Ji-Hye Paik
- Department of Pathology and Laboratory Medicine, Weill Cornell Medical College, New York, New York 10065, USA
| | - Laura Frasson
- Venetian Institute of Molecular Medicine, via Orus 2, 35129 Padova, Italy
| | - Anke Seydel
- Venetian Institute of Molecular Medicine, via Orus 2, 35129 Padova, Italy
| | - Jinghui Zhao
- Department of Cell Biology, Harvard Medical School, Boston, Massachusetts 02115, USA
| | - Reimar Abraham
- Department of Cancer Biology, U3 Pharma GmbH, Martinsried 82152, Germany
| | - Alfred L Goldberg
- Department of Cell Biology, Harvard Medical School, Boston, Massachusetts 02115, USA
| | - Bert Blaauw
- Department of Biomedical Sciences, University of Padova, 35131 Padova, Italy
| | - Ronald A DePinho
- Department of Cancer Biology, University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA
| | - Marco Sandri
- 1] Venetian Institute of Molecular Medicine, via Orus 2, 35129 Padova, Italy [2] Department of Biomedical Sciences, University of Padova, 35131 Padova, Italy [3] Institute of Neuroscience, Consiglio Nazionale delle Ricerche, 35129 Padova, Italy [4] Department of Medicine, McGill University, Montreal, Quebec H3AoG4, Canada [5] Dulbecco Telethon Institute at Telethon Institute of Genetics and Medicine (TIGEM), 80131 Napoli, Italy
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49
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Southard S, Low S, Li L, Rozo M, Harvey T, Fan CM, Lepper C. A series of Cre-ER(T2) drivers for manipulation of the skeletal muscle lineage. Genesis 2014; 52:759-70. [PMID: 24844572 DOI: 10.1002/dvg.22792] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2014] [Revised: 05/14/2014] [Accepted: 05/16/2014] [Indexed: 12/20/2022]
Abstract
We report the generation of five mouse strains with the tamoxifen-inducible Cre (Cre-ER(T) (2) ; CE) gene cassette knocked into the endogenous loci of Pax3, Myod1, Myog, Myf6, and Myl1, collectively as a resource for the skeletal muscle research community. We characterized these CE strains using the Cre reporter mice, R26R(L) (acZ) , during embryogenesis and show that they direct tightly controlled tamoxifen-inducible reporter expression within the expected cell lineage determined by each myogenic gene. We also examined a few selected adult skeletal muscle groups for tamoxifen-inducible reporter expression. None of these new CE alleles direct reporter expression in the cardiac muscle. All these alleles follow the same knock-in strategy by replacing the first exon of each gene with the CE cassette, rendering them null alleles of the endogenous gene. Advantages and disadvantages of this design are discussed. Although we describe potential immediate use of these strains, their utility likely extends beyond foreseeable questions in skeletal muscle biology.
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Affiliation(s)
- Sheryl Southard
- Department of Embryology, Carnegie Institution for Science, Baltimore, Maryland
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50
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Abstract
Bone and muscle mass are highly correlated. In part, this is a consequence of both tissues sharing common genetic determinants. In addition, both tissues are responsive to their mechanical environments. New genetic tools in mice will allow genes of interest to be inactivated in experimentally defined contexts, thus allowing investigators to distinguish direct effects on each tissue from physiological responses to a primary phenotype in the other.
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