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Yuan R, Luo X, Liang Z, Cai S, Zhao Y, Zhu Q, Li E, Liu X, Mo D, Chen Y. UBE2C promotes myoblast differentiation and skeletal muscle regeneration through the Akt signaling pathway. Acta Biochim Biophys Sin (Shanghai) 2024; 56:1065-1071. [PMID: 38690615 PMCID: PMC11322864 DOI: 10.3724/abbs.2024062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2023] [Accepted: 02/09/2024] [Indexed: 05/02/2024] Open
Abstract
Ubiquitin-conjugation enzyme E2C (UBE2C) is a crucial component of the ubiquitin-proteasome system that is involved in numerous cancers. In this study, we find that UBE2C expression is significantly increased in mouse embryos, a critical stage during skeletal muscle development. We further investigate the function of UBE2C in myogenesis. Knockdown of UBE2C inhibits C2C12 cell differentiation and decreases the expressions of MyoG and MyHC, while overexpression of UBE2C promotes C2C12 cell differentiation. Additionally, knockdown of UBE2C, specifically in the tibialis anterior muscle (TA), severely impedes muscle regeneration in vivo. Mechanistically, we show that UBE2C knockdown reduces the level of phosphorylated protein kinase B (p-Akt) and promotes the degradation of Akt. These findings suggest that UBE2C plays a critical role in myoblast differentiation and muscle regeneration and that UBE2C regulates myogenesis through the Akt signaling pathway.
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Affiliation(s)
- Renqiang Yuan
- State Key Laboratory of BiocontrolSchool of Life SciencesSun Yat-sen UniversityGuangzhou510275China
- Guangxi Yangxiang Agriculture and Husbandry Co.Ltd.Guigang537100China
| | - Xiaorong Luo
- State Key Laboratory of BiocontrolSchool of Life SciencesSun Yat-sen UniversityGuangzhou510275China
| | - Ziyun Liang
- State Key Laboratory of BiocontrolSchool of Life SciencesSun Yat-sen UniversityGuangzhou510275China
| | - Shufang Cai
- State Key Laboratory of BiocontrolSchool of Life SciencesSun Yat-sen UniversityGuangzhou510275China
| | - Yunxiang Zhao
- Guangxi Yangxiang Agriculture and Husbandry Co.Ltd.Guigang537100China
| | - Qi Zhu
- State Key Laboratory of BiocontrolSchool of Life SciencesSun Yat-sen UniversityGuangzhou510275China
| | - Enru Li
- State Key Laboratory of BiocontrolSchool of Life SciencesSun Yat-sen UniversityGuangzhou510275China
| | - Xiaohong Liu
- State Key Laboratory of BiocontrolSchool of Life SciencesSun Yat-sen UniversityGuangzhou510275China
| | - Delin Mo
- State Key Laboratory of BiocontrolSchool of Life SciencesSun Yat-sen UniversityGuangzhou510275China
| | - Yaosheng Chen
- State Key Laboratory of BiocontrolSchool of Life SciencesSun Yat-sen UniversityGuangzhou510275China
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Olthof MGL, Hasler A, Valdivieso P, Flück M, Gerber C, Gehrke R, Klein K, von Rechenberg B, Snedeker JG, Wieser K. Poly(ADP-Ribose) Polymerases-Inhibitor Talazoparib Inhibits Muscle Atrophy and Fatty Infiltration in a Tendon Release Infraspinatus Sheep Model: A Pilot Study. Metabolites 2024; 14:187. [PMID: 38668315 PMCID: PMC11051840 DOI: 10.3390/metabo14040187] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2024] [Revised: 03/13/2024] [Accepted: 03/20/2024] [Indexed: 04/28/2024] Open
Abstract
Structural muscle changes, including muscle atrophy and fatty infiltration, follow rotator cuff tendon tear and are associated with a high repair failure rate. Despite extensive research efforts, no pharmacological therapy is available to successfully prevent both muscle atrophy and fatty infiltration after tenotomy of tendomuscular unit without surgical repair. Poly(ADP-ribose) polymerases (PARPs) are identified as a key transcription factors involved in the maintenance of cellular homeostasis. PARP inhibitors have been shown to influence muscle degeneration, including mitochondrial hemostasis, oxidative stress, inflammation and metabolic activity, and reduced degenerative changes in a knockout mouse model. Tenotomized infraspinatus were assessed for muscle degeneration for 16 weeks using a Swiss Alpine sheep model (n = 6). All sheep received daily oral administration of 0.5 mg Talazoparib. Due to animal ethics, the treatment group was compared with three different controls from prior studies of our institution. To mitigate potential batch heterogeneity, PARP-I was evaluated in comparison with three distinct control groups (n = 6 per control group) using the same protocol without treatment. The control sheep were treated with an identical study protocol without Talazoparib treatment. Muscle atrophy and fatty infiltration were evaluated at 0, 6 and 16 weeks post-tenotomy using DIXON-MRI. The controls and PARP-I showed a significant (control p < 0.001, PARP-I p = 0.01) decrease in muscle volume after 6 weeks. However, significantly less (p = 0.01) atrophy was observed in PARP-I after 6 weeks (control 1: 76.6 ± 8.7%; control 2: 80.3 ± 9.3%, control 3: 73.8 ± 6.7% vs. PARP-I: 90.8 ± 5.1% of the original volume) and 16 weeks (control 1: 75.7 ± 9.9; control 2: 74.2 ± 5.6%; control 3: 75.3 ± 7.4% vs. PARP-I 93.3 ± 10.6% of the original volume). All experimental groups exhibited a statistically significant (p < 0.001) augmentation in fatty infiltration following a 16-week period when compared to the initial timepoint. However, the PARP-I showed significantly less fatty infiltration (p < 0.003) compared to all controls (control 1: 55.6 ± 6.7%, control 2: 53.4 ± 9.4%, control 3: 52.0 ± 12.8% vs. PARP-I: 33.5 ± 8.4%). Finally, a significantly (p < 0.04) higher proportion and size of fast myosin heavy chain-II fiber type was observed in the treatment group. This study shows that PARP-inhibition with Talazoparib inhibits the progression of both muscle atrophy and fatty infiltration over 16 weeks in retracted sheep musculotendinous units.
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Affiliation(s)
- Maurits G. L. Olthof
- Department of Orthopaedics, Balgrist, University of Zurich, Forchstrasse 340, 8008 Zurich, Switzerland; (A.H.); (C.G.); (J.G.S.); (K.W.)
| | - Anita Hasler
- Department of Orthopaedics, Balgrist, University of Zurich, Forchstrasse 340, 8008 Zurich, Switzerland; (A.H.); (C.G.); (J.G.S.); (K.W.)
| | - Paola Valdivieso
- Laboratory for Muscle Plasticity, Department of Orthopedics, Balgrist Campus, University of Zurich, Forchstrasse 340, 8008 Zurich, Switzerland; (P.V.); (M.F.)
| | - Martin Flück
- Laboratory for Muscle Plasticity, Department of Orthopedics, Balgrist Campus, University of Zurich, Forchstrasse 340, 8008 Zurich, Switzerland; (P.V.); (M.F.)
| | - Christian Gerber
- Department of Orthopaedics, Balgrist, University of Zurich, Forchstrasse 340, 8008 Zurich, Switzerland; (A.H.); (C.G.); (J.G.S.); (K.W.)
| | - Rieke Gehrke
- Musculoskeletal Research Unit, Center for Applied Biotechnology and Molecular Medicine, Equine Department, Vetsuisse Faculty, Winterthurerstrasse 190, 8057 Zurich, Switzerland; (R.G.); (K.K.); (B.v.R.)
| | - Karina Klein
- Musculoskeletal Research Unit, Center for Applied Biotechnology and Molecular Medicine, Equine Department, Vetsuisse Faculty, Winterthurerstrasse 190, 8057 Zurich, Switzerland; (R.G.); (K.K.); (B.v.R.)
| | - Brigitte von Rechenberg
- Musculoskeletal Research Unit, Center for Applied Biotechnology and Molecular Medicine, Equine Department, Vetsuisse Faculty, Winterthurerstrasse 190, 8057 Zurich, Switzerland; (R.G.); (K.K.); (B.v.R.)
| | - Jess G. Snedeker
- Department of Orthopaedics, Balgrist, University of Zurich, Forchstrasse 340, 8008 Zurich, Switzerland; (A.H.); (C.G.); (J.G.S.); (K.W.)
- Institute for Biomechanics, ETH Zurich, Gloriastrasse 37/39, 8092 Zürich, Switzerland
| | - Karl Wieser
- Department of Orthopaedics, Balgrist, University of Zurich, Forchstrasse 340, 8008 Zurich, Switzerland; (A.H.); (C.G.); (J.G.S.); (K.W.)
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Serova M, Didry-Barca B, Deloux R, Foucault AS, Veillet S, Lafont R, Dilda PJ, Latil M. BIO101 stimulates myoblast differentiation and improves muscle function in adult and old mice. J Cachexia Sarcopenia Muscle 2024; 15:55-66. [PMID: 38064183 PMCID: PMC10834314 DOI: 10.1002/jcsm.13326] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Revised: 06/14/2023] [Accepted: 08/11/2023] [Indexed: 02/03/2024] Open
Abstract
BACKGROUND Muscle aging is associated with a consistent decrease in the ability of muscle tissue to regenerate following intrinsic muscle degradation, injury or overuse. Age-related imbalance of protein synthesis and degradation, mainly regulated by AKT/mTOR pathway, leads to progressive loss of muscle mass. Maintenance of anabolic and regenerative capacities of skeletal muscles may be regarded as a therapeutic option for sarcopenia and other muscle wasting diseases. Our previous studies have demonstrated that BIO101, a pharmaceutical grade 20-hydroxyecdysone, increases protein synthesis through the activation of MAS receptor involved in the protective arm of renin-angiotensin-aldosterone system. The purpose of the present study was to assess the anabolic and pro-differentiating properties of BIO101 on C2C12 muscle cells in vitro and to investigate its effects on adult and old mice models in vivo. METHODS The effects of BIO101 on C2C12 differentiation were assessed using myogenic transcription factors and protein expression of major kinases of AKT/mTOR pathway by Western blot. The in vivo effects of BIO101 have been investigated in BIO101 orally-treated (50 mg/kg/day) adult mice (3 months) for 28 days. To demonstrate potential beneficial effect of BIO101 treatment in a sarcopenic mouse model, we use orally treated 22-month-old C57Bl6/J mice, for 14 weeks with vehicle or BIO101. Mice body and muscle weight were recorded. Physical performances were assessed using running capacity and muscle contractility tests. RESULTS Anabolic properties of BIO101 were confirmed by the rapid activation of AKT/mTOR, leading to an increase of C2C12 myotubes diameters (+26%, P < 0.001). Pro-differentiating effects of BIO101 on C2C12 myoblasts were revealed by increased expression of muscle-specific differentiation transcription factors (MyoD, myogenin), resulting in increased fusion index and number of nuclei per myotube (+39% and +53%, respectively, at day 6). These effects of BIO101 were like those of angiotensin (1-7) and were abolished with the use of A779, a MAS receptor specific antagonist. Chronic BIO101 oral treatment induced AKT/mTOR activation and anabolic effects accompanied with improved physical performances in adult and old animals (maximal running distance and maximal running velocity). CONCLUSIONS Our data suggest beneficial anabolic and pro-differentiating effects of BIO101 rendering BIO101 a potent drug candidate for treating sarcopenia and possibly other muscle wasting disorders.
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Affiliation(s)
| | | | | | | | | | - René Lafont
- Biophytis, Sorbonne Université, Paris, France
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Dawuti A, Ma L, An X, Guan J, Zhou C, He L, Xu Y, Han B, Abulizi A. Exploring the effect and mechanism of Aloin A against cancer cachexia-induced muscle atrophy via network pharmacology, molecular docking, molecular dynamics and experimental validation. Aging (Albany NY) 2023; 15:15557-15577. [PMID: 38180061 PMCID: PMC10781478 DOI: 10.18632/aging.205416] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2023] [Accepted: 11/06/2023] [Indexed: 01/06/2024]
Abstract
80% of advanced cancer patients suffer from cachexia, but there are no FDA-approved drugs. Therefore, it is imperative to discover potential drugs. OBJECTIVE This study aims at exploring the effect and targets of Aloin A against cancer cachexia (CC)-induced muscle atrophy. METHODS Network pharmacology, molecular docking, molecular dynamics (MD) and animal model of CC-induced muscle atrophy with a series of behavior tests, muscle quality, HE staining and RT-PCR were performed to investigate the anticachectic effects and targets of Aloin A and its molecular mechanism. RESULTS Based on network pharmacology, 51 potential targets of Aloin A on CC-induced muscle atrophy were found, and then 10 hub genes were predicted by the PPI network. Next, KEGG and GO enrichment analysis showed that the anticachectic effect of Aloin A is associated with PI3K-AKT, MAPK, TNF, TLR, etc., pathways, and biological processes like inflammation, apoptosis and cell proliferation. Molecular docking and MD results showed good binding ability between the Aloin A and key targets. Moreover, experiments in vivo demonstrated that Aloin A effectively rescued muscle function and wasting by improving muscle quality, mean CSA, and distribution of muscle fibers by regulating HSP90AA1/AKT signaling in tumor-bearing mice. CONCLUSION This study offers new insights for researchers to understand the effect and mechanism of Aloin A against CC using network pharmacology, molecular docking, MD and experimental validation, and Aloin A retards CC-induced muscle wasting through multiple targets and pathways, including HSP90AA1/AKT signaling, which provides evidence for Aloin A as a potential therapy for cancer cachexia in clinic.
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Affiliation(s)
- Awaguli Dawuti
- Key Laboratory of Xinjiang Phytomedicine Resource and Utilization, Ministry of Education, College of Pharmacy, Shihezi University, Shihezi 832002, China
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China
| | - Lisha Ma
- Key Laboratory of Xinjiang Phytomedicine Resource and Utilization, Ministry of Education, College of Pharmacy, Shihezi University, Shihezi 832002, China
| | - Xueyan An
- Key Laboratory of Xinjiang Phytomedicine Resource and Utilization, Ministry of Education, College of Pharmacy, Shihezi University, Shihezi 832002, China
| | - Jiawei Guan
- Key Laboratory of Xinjiang Phytomedicine Resource and Utilization, Ministry of Education, College of Pharmacy, Shihezi University, Shihezi 832002, China
| | - Changdong Zhou
- Key Laboratory of Xinjiang Phytomedicine Resource and Utilization, Ministry of Education, College of Pharmacy, Shihezi University, Shihezi 832002, China
| | - Linyun He
- Key Laboratory of Xinjiang Phytomedicine Resource and Utilization, Ministry of Education, College of Pharmacy, Shihezi University, Shihezi 832002, China
| | - Yue Xu
- Division of Pharmaceutics and Pharmacology, College of Pharmacy, The Ohio State University, Columbus, OH 43210, USA
| | - Bo Han
- Key Laboratory of Xinjiang Phytomedicine Resource and Utilization, Ministry of Education, College of Pharmacy, Shihezi University, Shihezi 832002, China
| | - Abudumijiti Abulizi
- Key Laboratory of Xinjiang Phytomedicine Resource and Utilization, Ministry of Education, College of Pharmacy, Shihezi University, Shihezi 832002, China
- State Key Laboratory of Natural and Biomimetic Drugs, Peking University, Beijing 100191, China
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Bersiner K, Park SY, Schaaf K, Yang WH, Theis C, Jacko D, Gehlert S. Resistance exercise: a mighty tool that adapts, destroys, rebuilds and modulates the molecular and structural environment of skeletal muscle. Phys Act Nutr 2023; 27:78-95. [PMID: 37583075 PMCID: PMC10440184 DOI: 10.20463/pan.2023.0021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2023] [Revised: 06/29/2023] [Accepted: 06/30/2023] [Indexed: 08/17/2023] Open
Abstract
PURPOSE Skeletal muscle regulates health and performance by maintaining or increasing strength and muscle mass. Although the molecular mechanisms in response to resistance exercise (RE) significantly target the activation of protein synthesis, a plethora of other mechanisms and structures must be involved in orchestrating the communication, repair, and restoration of homeostasis after RE stimulation. In practice, RE can be modulated by variations in intensity, continuity and volume, which affect molecular responses and skeletal muscle adaptation. Knowledge of these aspects is important with respect to planning of training programs and assessing the impact of RE training on skeletal muscle. METHODS In this narrative review, we introduce general aspects of skeletal muscle substructures that adapt in response to RE. We further highlighted the molecular mechanisms that control human skeletal muscle anabolism, degradation, repair and memory in response to acute and repeated RE and linked these aspects to major training variables. RESULTS Although RE is a key stimulus for the activation of skeletal muscle anabolism, it also induces myofibrillar damage. Nevertheless, to increase muscle mass accompanied by a corresponding adaptation of the essential substructures of the sarcomeric environment, RE must be continuously repeated. This requires the permanent engagement of molecular mechanisms that re-establish skeletal muscle integrity after each RE-induced muscle damage. CONCLUSION Various molecular regulators coordinately control the adaptation of skeletal muscle after acute and repeated RE and expand their actions far beyond muscle growth. Variations of key resistance training variables likely affect these mechanisms without affecting muscle growth.
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Affiliation(s)
- Käthe Bersiner
- Department for Biosciences of Sports, Institute of Sports Science, University of Hildesheim, Hildesheim, Germany
| | - So-Young Park
- Graduate School of Sports Medicine, CHA University, Pocheon, Republic of Korea
| | - Kirill Schaaf
- Department of Molecular and Cellular Sports Medicine, Institute of Cardiovascular Research and Sports Medicine, German Sport University Cologne, Cologne, Germany
| | - Woo-Hwi Yang
- Graduate School of Sports Medicine, CHA University, Pocheon, Republic of Korea
- Department of Medicine, General Graduate School, CHA University, Pocheon, Republic of Korea
| | - Christian Theis
- Center for Anaesthesiology, Helios University Hospital Wuppertal, Wuppertal, Germany
| | - Daniel Jacko
- Department of Molecular and Cellular Sports Medicine, Institute of Cardiovascular Research and Sports Medicine, German Sport University Cologne, Cologne, Germany
| | - Sebastian Gehlert
- Department for Biosciences of Sports, Institute of Sports Science, University of Hildesheim, Hildesheim, Germany
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Grunow JJ, Gan T, Lewald H, Martyn JAJ, Blobner M, Schaller SJ. Insulin signaling in skeletal muscle during inflammation and/or immobilisation. Intensive Care Med Exp 2023; 11:16. [PMID: 36967414 PMCID: PMC10040391 DOI: 10.1186/s40635-023-00503-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2022] [Accepted: 02/20/2023] [Indexed: 03/28/2023] Open
Abstract
BACKGROUND The decline in the downstream signal transduction pathway of anabolic hormone, insulin, could play a key role in the muscle atrophy and insulin resistance observed in patients with intensive care unit acquired weakness (ICUAW). This study investigated the impact of immobilisation via surgical knee and ankle fixation and inflammation via Corynebacterium parvum injection, alone and in combination, as risk factors for altering insulin transduction and, therefore, their role in ICUAW. RESULTS Muscle weight was significantly decreased due to immobilisation [estimated effect size (95% CI) - 0.10 g (- 0.12 to - 0.08); p < 0.001] or inflammation [estimated effect size (95% CI) - 0.11 g (- 0.13 to - 0.09); p < 0.001] with an additive effect of both combined (p = 0.024). pAkt was only detectable after insulin stimulation [estimated effect size (95% CI) 85.1-fold (76.2 to 94.0); p < 0.001] irrespective of the group and phosphorylation was not impaired by the different perturbations. Nevertheless, the phosphorylation of GSK3 observed in the control group after insulin stimulation was decreased in the immobilisation [estimated effect size (95% CI) - 40.2 (- 45.6 to - 34.8)] and inflammation [estimated effect size (95% CI) - 55.0 (- 60.4 to - 49.5)] groups. The expression of phosphorylated GS (pGS) was decreased after insulin stimulation in the control group and significantly increased in the immobilisation [estimated effect size (95% CI) 70.6-fold (58.8 to 82.4)] and inflammation [estimated effect size (95% CI) 96.7 (85.0 to 108.5)] groups. CONCLUSIONS Both immobilisation and inflammation significantly induce insulin resistance, i.e., impair the insulin signaling pathway downstream of Akt causing insufficient GSK phosphorylation and, therefore, its activation which caused increased glycogen synthase phosphorylation, which could contribute to muscle atrophy of immobilisation and inflammation.
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Affiliation(s)
- Julius J Grunow
- Charité - Universitätsmedizin Berlin, corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Department of Anesthesiology and Operative Intensive Care Medicine (CVK, CCM), Charitéplatz 1, 10117, Berlin, Germany
| | - Thomas Gan
- Technical University of Munich, School of Medicine, Klinikum rechts der Isar, Department of Anesthesiology and Intensive Care, Ismaninger Straße 22, 81675, Munich, Bavaria, Germany
| | - Heidrun Lewald
- Technical University of Munich, School of Medicine, Klinikum rechts der Isar, Department of Anesthesiology and Intensive Care, Ismaninger Straße 22, 81675, Munich, Bavaria, Germany
| | - J A Jeevendra Martyn
- Department of Anaesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Shriners Hospitals for Children®-Boston, and Harvard Medical School, 51 Blossom Street, Room 206, Boston, 02114, MA, USA
| | - Manfred Blobner
- Technical University of Munich, School of Medicine, Klinikum rechts der Isar, Department of Anesthesiology and Intensive Care, Ismaninger Straße 22, 81675, Munich, Bavaria, Germany
| | - Stefan J Schaller
- Charité - Universitätsmedizin Berlin, corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Department of Anesthesiology and Operative Intensive Care Medicine (CVK, CCM), Charitéplatz 1, 10117, Berlin, Germany.
- Technical University of Munich, School of Medicine, Klinikum rechts der Isar, Department of Anesthesiology and Intensive Care, Ismaninger Straße 22, 81675, Munich, Bavaria, Germany.
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Paez HG, Pitzer CR, Alway SE. Age-Related Dysfunction in Proteostasis and Cellular Quality Control in the Development of Sarcopenia. Cells 2023; 12:cells12020249. [PMID: 36672183 PMCID: PMC9856405 DOI: 10.3390/cells12020249] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2022] [Revised: 01/04/2023] [Accepted: 01/04/2023] [Indexed: 01/11/2023] Open
Abstract
Sarcopenia is a debilitating skeletal muscle disease that accelerates in the last decades of life and is characterized by marked deficits in muscle strength, mass, quality, and metabolic health. The multifactorial causes of sarcopenia have proven difficult to treat and involve a complex interplay between environmental factors and intrinsic age-associated changes. It is generally accepted that sarcopenia results in a progressive loss of skeletal muscle function that exceeds the loss of mass, indicating that while loss of muscle mass is important, loss of muscle quality is the primary defect with advanced age. Furthermore, preclinical models have suggested that aged skeletal muscle exhibits defects in cellular quality control such as the degradation of damaged mitochondria. Recent evidence suggests that a dysregulation of proteostasis, an important regulator of cellular quality control, is a significant contributor to the aging-associated declines in muscle quality, function, and mass. Although skeletal muscle mammalian target of rapamycin complex 1 (mTORC1) plays a critical role in cellular control, including skeletal muscle hypertrophy, paradoxically, sustained activation of mTORC1 recapitulates several characteristics of sarcopenia. Pharmaceutical inhibition of mTORC1 as well as caloric restriction significantly improves muscle quality in aged animals, however, the mechanisms controlling cellular proteostasis are not fully known. This information is important for developing effective therapeutic strategies that mitigate or prevent sarcopenia and associated disability. This review identifies recent and historical understanding of the molecular mechanisms of proteostasis driving age-associated muscle loss and suggests potential therapeutic interventions to slow or prevent sarcopenia.
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Affiliation(s)
- Hector G. Paez
- Department of Physiology, College of Medicine, University of Tennessee Health Science Center, Memphis, TN 38163, USA
- Integrated Biomedical Sciences Graduate Program, College of Graduate Health Sciences, University of Tennessee Health Science Center, Memphis, TN 38163, USA
- Laboratory of Muscle Biology and Sarcopenia, Department of Physical Therapy, College of Health Professions, University of Tennessee Health Science Center, Memphis, TN 38163, USA
- Center for Muscle, Metabolism and Neuropathology, Division of Regenerative and Rehabilitation Sciences, College of Health Professions, University of Tennessee Health Science Center, Memphis, TN 38163, USA
| | - Christopher R. Pitzer
- Department of Physiology, College of Medicine, University of Tennessee Health Science Center, Memphis, TN 38163, USA
- Integrated Biomedical Sciences Graduate Program, College of Graduate Health Sciences, University of Tennessee Health Science Center, Memphis, TN 38163, USA
- Laboratory of Muscle Biology and Sarcopenia, Department of Physical Therapy, College of Health Professions, University of Tennessee Health Science Center, Memphis, TN 38163, USA
- Center for Muscle, Metabolism and Neuropathology, Division of Regenerative and Rehabilitation Sciences, College of Health Professions, University of Tennessee Health Science Center, Memphis, TN 38163, USA
| | - Stephen E. Alway
- Department of Physiology, College of Medicine, University of Tennessee Health Science Center, Memphis, TN 38163, USA
- Integrated Biomedical Sciences Graduate Program, College of Graduate Health Sciences, University of Tennessee Health Science Center, Memphis, TN 38163, USA
- Laboratory of Muscle Biology and Sarcopenia, Department of Physical Therapy, College of Health Professions, University of Tennessee Health Science Center, Memphis, TN 38163, USA
- Center for Muscle, Metabolism and Neuropathology, Division of Regenerative and Rehabilitation Sciences, College of Health Professions, University of Tennessee Health Science Center, Memphis, TN 38163, USA
- The Tennessee Institute of Regenerative Medicine, Memphis, TN 38163, USA
- Correspondence:
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8
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No SH, Moon HW, Kim JS. Effect of chronic alcohol intake on the expression of muscle atrophy-related proteins in growing rats. J Exerc Rehabil 2022; 18:235-239. [PMID: 36110257 PMCID: PMC9449086 DOI: 10.12965/jer.2244314.157] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2022] [Accepted: 07/10/2022] [Indexed: 11/22/2022] Open
Abstract
In this study, the effect of chronic alcohol intake for 4 weeks on the muscular atrophy factors of rat skeletal muscle was studied using 6-week-old growing Sprague-Dawley rats. Experimental animals were classified into a control group and an alcohol intake group. The alcohol intake group consumed alcohol orally at a concentration of 3-g/kg body weight every day for 4 weeks. The control group consumed tap water in the same way. After 4 weeks alcohol ingestion, glucose, total cholesterol, triglyceride, and high-density lipoprotein cholesterol in serum levels were measured. Western blot was performed to detect the expressions of muscle RING-finger protein-1 (MuRF1), protein kinase B (Akt), phosphorylated Akt (p-Akt), forkhead box O (FoxO), phosphorylated FoxO (p-FoxO), p38, and phosphorylated p38 (p-p38). Results of this experiment showed that chronic alcohol intake enhanced triglyceride concentration. Chronic alcohol intake increased MuRF1 expression to promote muscle proteolysis and decreased p-Akt/Akt ratio and p-FoxO/FoxO ratio to inhibit skeletal muscle growth. Therefore, alcohol consumption has been shown to cause muscle atrophy.
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Affiliation(s)
- Sung-Hwan No
- Department of Physical Education, College of Education, Inha University, Incheon,
Korea
| | - Hwang-Woon Moon
- Department of Sports and Outdoors, College of Bio Convergence, Eulji University, Seongnam,
Korea
| | - Jun-Su Kim
- Department of Sports and Outdoors, College of Bio Convergence, Eulji University, Seongnam,
Korea
- Corresponding author: Jun-Su Kim, Department of Sports and Outdoors, College of Bio Convergence, Eulji University, 553 Sanseong-daero, Sujeong-gu, Seongnam 13135, Korea,
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Zumbaugh MD, Johnson SE, Shi TH, Gerrard DE. Molecular and biochemical regulation of skeletal muscle metabolism. J Anim Sci 2022; 100:6652332. [PMID: 35908794 PMCID: PMC9339271 DOI: 10.1093/jas/skac035] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Accepted: 02/02/2022] [Indexed: 12/13/2022] Open
Abstract
Skeletal muscle hypertrophy is a culmination of catabolic and anabolic processes that are interwoven into major metabolic pathways, and as such modulation of skeletal muscle metabolism may have implications on animal growth efficiency. Muscle is composed of a heterogeneous population of muscle fibers that can be classified by metabolism (oxidative or glycolytic) and contractile speed (slow or fast). Although slow fibers (type I) rely heavily on oxidative metabolism, presumably to fuel long or continuous bouts of work, fast fibers (type IIa, IIx, and IIb) vary in their metabolic capability and can range from having a high oxidative capacity to a high glycolytic capacity. The plasticity of muscle permits continuous adaptations to changing intrinsic and extrinsic stimuli that can shift the classification of muscle fibers, which has implications on fiber size, nutrient utilization, and protein turnover rate. The purpose of this paper is to summarize the major metabolic pathways in skeletal muscle and the associated regulatory pathways.
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Affiliation(s)
- Morgan D Zumbaugh
- Department of Animal and Poultry Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA
| | - Sally E Johnson
- Department of Animal and Poultry Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA
| | - Tim H Shi
- Department of Animal and Poultry Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA
| | - David E Gerrard
- Department of Animal and Poultry Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA
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10
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Attwaters M, Hughes SM. Cellular and molecular pathways controlling muscle size in response to exercise. FEBS J 2022; 289:1428-1456. [PMID: 33755332 DOI: 10.1111/febs.15820] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Revised: 02/27/2021] [Accepted: 03/12/2021] [Indexed: 12/14/2022]
Abstract
From the discovery of ATP and motor proteins to synaptic neurotransmitters and growth factor control of cell differentiation, skeletal muscle has provided an extreme model system in which to understand aspects of tissue function. Muscle is one of the few tissues that can undergo both increase and decrease in size during everyday life. Muscle size depends on its contractile activity, but the precise cellular and molecular pathway(s) by which the activity stimulus influences muscle size and strength remain unclear. Four correlates of muscle contraction could, in theory, regulate muscle growth: nerve-derived signals, cytoplasmic calcium dynamics, the rate of ATP consumption and physical force. Here, we summarise the evidence for and against each stimulus and what is known or remains unclear concerning their molecular signal transduction pathways and cellular effects. Skeletal muscle can grow in three ways, by generation of new syncytial fibres, addition of nuclei from muscle stem cells to existing fibres or increase in cytoplasmic volume/nucleus. Evidence suggests the latter two processes contribute to exercise-induced growth. Fibre growth requires increase in sarcolemmal surface area and cytoplasmic volume at different rates. It has long been known that high-force exercise is a particularly effective growth stimulus, but how this stimulus is sensed and drives coordinated growth that is appropriately scaled across organelles remains a mystery.
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Affiliation(s)
- Michael Attwaters
- Randall Centre for Cell and Molecular Biophysics, School of Basic and Medical Biosciences, King's College London, UK
| | - Simon M Hughes
- Randall Centre for Cell and Molecular Biophysics, School of Basic and Medical Biosciences, King's College London, UK
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11
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Jaiswal N, Gavin M, Loro E, Sostre‐Colón J, Roberson PA, Uehara K, Rivera‐Fuentes N, Neinast M, Arany Z, Kimball SR, Khurana TS, Titchenell PM. AKT controls protein synthesis and oxidative metabolism via combined mTORC1 and FOXO1 signalling to govern muscle physiology. J Cachexia Sarcopenia Muscle 2022; 13:495-514. [PMID: 34751006 PMCID: PMC8818654 DOI: 10.1002/jcsm.12846] [Citation(s) in RCA: 28] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Revised: 09/14/2021] [Accepted: 10/05/2021] [Indexed: 01/29/2023] Open
Abstract
BACKGROUND Skeletomuscular diseases result in significant muscle loss and decreased performance, paralleled by a loss in mitochondrial and oxidative capacity. Insulin and insulin-like growth factor-1 (IGF-1) are two potent anabolic hormones that activate a host of signalling intermediates including the serine/threonine kinase AKT to influence skeletal muscle physiology. Defective AKT signalling is associated with muscle pathology, including cachexia, sarcopenia, and disuse; however, the mechanistic underpinnings remain unresolved. METHODS To elucidate the role of AKT signalling in muscle mass and physiology, we generated both congenital and inducible mouse models of skeletal muscle-specific AKT deficiency. To understand the downstream mechanisms mediating AKT's effects on muscle biology, we generated mice lacking AKT1/2 and FOXO1 (M-AKTFOXO1TKO and M-indAKTFOXO1TKO) to inhibit downstream FOXO1 signalling, AKT1/2 and TSC1 (M-AKTTSCTKO and M-indAKTTSCTKO) to activate mTORC1, and AKT1/2, FOXO1, and TSC1 (M-QKO and M-indQKO) to simultaneously activate mTORC1 and inhibit FOXO1 in AKT-deficient skeletal muscle. Muscle proteostasis and physiology were assessed using multiple assays including metabolic labelling, mitochondrial function, fibre typing, ex vivo physiology, and exercise performance. RESULTS Here, we show that genetic ablation of skeletal muscle AKT signalling resulted in decreased muscle mass and a loss of oxidative metabolism and muscle performance. Specifically, deletion of muscle AKT activity during development or in adult mice resulted in a significant reduction in muscle growth by 30-40% (P < 0.0001; n = 12-20) and 15% (P < 0.01 and P < 0.0001; n = 20-30), respectively. Interestingly, this reduction in muscle mass was primarily due to an ~40% reduction in protein synthesis in both M-AKTDKO and M-indAKTDKO muscles (P < 0.05 and P < 0.01; n = 12-20) without significant changes in proteolysis or autophagy. Moreover, a significant reduction in oxidative capacity was observed in both M-AKTDKO (P < 0.05, P < 0.01 and P < 0.001; n = 5-12) and M-indAKTDKO (P < 0.05 and P < 0.01; n = 4). Mechanistically, activation and inhibition of mTORC1/FOXO1, respectively, but neither alone, were sufficient to restore protein synthesis, muscle oxidative capacity, and muscle function in the absence of AKT in vivo. In a mouse model of disuse-induced muscle loss, simultaneous activation of mTORC1 and inhibition of FOXO1 preserved muscle mass following immobilization (~5-10% reduction in casted M-indFOXO1TSCDKO muscles vs. ~30-40% casted M-indControl muscles, P < 0.05 and P < 0.0001; n = 8-16). CONCLUSIONS Collectively, this study provides novel insights into the AKT-dependent mechanisms that underlie muscle protein homeostasis, function, and metabolism in both normal physiology and disuse-induced muscle wasting.
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Affiliation(s)
- Natasha Jaiswal
- Institute for Diabetes, Obesity, and MetabolismPerelman School of Medicine at the University of PennsylvaniaPhiladelphiaPAUSA
| | - Matthew Gavin
- Institute for Diabetes, Obesity, and MetabolismPerelman School of Medicine at the University of PennsylvaniaPhiladelphiaPAUSA
| | - Emanuele Loro
- Department of PhysiologyPerelman School of Medicine at the University of PennsylvaniaPhiladelphiaPAUSA
- Penn Muscle Institute, Department of PhysiologyPerelman School of Medicine at the University of PennsylvaniaPhiladelphiaPAUSA
| | - Jaimarie Sostre‐Colón
- Institute for Diabetes, Obesity, and MetabolismPerelman School of Medicine at the University of PennsylvaniaPhiladelphiaPAUSA
| | - Paul A. Roberson
- Department of Cellular and Molecular PhysiologyPenn State College of MedicineHersheyPAUSA
| | - Kahealani Uehara
- Institute for Diabetes, Obesity, and MetabolismPerelman School of Medicine at the University of PennsylvaniaPhiladelphiaPAUSA
| | - Nicole Rivera‐Fuentes
- Institute for Diabetes, Obesity, and MetabolismPerelman School of Medicine at the University of PennsylvaniaPhiladelphiaPAUSA
| | - Michael Neinast
- Institute for Diabetes, Obesity, and MetabolismPerelman School of Medicine at the University of PennsylvaniaPhiladelphiaPAUSA
- Cardiovascular InstitutePerelman School of Medicine at the University of PennsylvaniaPhiladelphiaPAUSA
| | - Zoltan Arany
- Institute for Diabetes, Obesity, and MetabolismPerelman School of Medicine at the University of PennsylvaniaPhiladelphiaPAUSA
- Cardiovascular InstitutePerelman School of Medicine at the University of PennsylvaniaPhiladelphiaPAUSA
| | - Scot R. Kimball
- Department of Cellular and Molecular PhysiologyPenn State College of MedicineHersheyPAUSA
| | - Tejvir S. Khurana
- Department of PhysiologyPerelman School of Medicine at the University of PennsylvaniaPhiladelphiaPAUSA
- Penn Muscle Institute, Department of PhysiologyPerelman School of Medicine at the University of PennsylvaniaPhiladelphiaPAUSA
| | - Paul M. Titchenell
- Institute for Diabetes, Obesity, and MetabolismPerelman School of Medicine at the University of PennsylvaniaPhiladelphiaPAUSA
- Department of PhysiologyPerelman School of Medicine at the University of PennsylvaniaPhiladelphiaPAUSA
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12
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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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13
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Yamada AK, Ferretti R, Matsumura CY, Antunes L, Silva CAD, Pertille A. Beta-hydroxy-beta-methylbutyrate associated with low-intensity exercise training improves skeletal muscle regeneration through the IGF-Akt pathway. Braz J Med Biol Res 2022; 55:e11597. [PMID: 35019034 PMCID: PMC8851911 DOI: 10.1590/1414-431x2021e11597] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Accepted: 11/09/2021] [Indexed: 11/30/2022] Open
Abstract
The effect of beta-hydroxy-beta-methylbutyrate (HMB) supplementation associated with exercise training at different intensities and frequencies on skeletal muscle regeneration of muscle-injured rats was investigated. Male Wistar rats were divided into sedentary and trained groups. The sedentary groups were subdivided into non-injured (SED-Ct), non-injured supplemented with HMB (SED-Ct-HMB), injured (SED), and injured with HMB (SED-HMB), and the trained groups were injured, supplemented with HMB, and then divided into training three times a week without load (HT3) or with load (HT3L) and training five times a week without load (HT5) and with load (HT5L). The rats received a daily dose of HMB associated with 60 min of swimming with or without 5% body mass load for 14 days. On the 15th day, cryoinjury was performed in the right tibialis anterior muscle (TA), and 48 h later, supplementation and training continued for 15 days. After the last session, the TA was dissected and a cross-sectional area (CSA) of muscle fibers was used to determine the percentage of CSA fibers and connective tissue (%CT), as well as the total and phosphorylated protein contents. SED-HMB showed increased CSA and decreased %CT and TGF-β when compared to SED. HT3 showed increased CSA and reduced %CT accompanied by increased IGF-1/Akt, myogenin, and MuRF1, and decreased TGF-β. The CSA of HT5L also increased, but at the cost of a higher %CT compared to the other groups. Our results demonstrated that HMB associated with training without load and with lower frequency per week may be a valuable strategy for skeletal muscle regeneration.
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Affiliation(s)
- A K Yamada
- Programa de Pós-Graduação em Ciências do Movimento Humano, Laboratório de Plasticidade Neuromuscular, Universidade Metodista de Piracicaba, Piracicaba, SP, Brasil
| | - R Ferretti
- Departamento de Biologia Estrutural e Funcional, Instituto de Biociências de Botucatu, Universidade Estadual Paulista, Botucatu, SP, Brasil
| | - C Y Matsumura
- Departamento de Biologia Estrutural e Funcional, Instituto de Biociências de Botucatu, Universidade Estadual Paulista, Botucatu, SP, Brasil
| | - L Antunes
- Programa de Pós-Graduação em Ciências do Movimento Humano, Laboratório de Plasticidade Neuromuscular, Universidade Metodista de Piracicaba, Piracicaba, SP, Brasil
| | - C A da Silva
- Instituto de Ciências da Saúde, Faculdade de Ciências da Saúde, Universidade Paulista - Swift, Campinas, SP, Brasil
| | - A Pertille
- Programa de Pós-Graduação em Ciências do Movimento Humano, Laboratório de Plasticidade Neuromuscular, Universidade Metodista de Piracicaba, Piracicaba, SP, Brasil
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14
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Pereira MG, Voltarelli VA, Tobias GC, de Souza L, Borges GS, Paixão AO, de Almeida NR, Bowen TS, Demasi M, Miyabara EH, Brum PC. Aerobic Exercise Training and In Vivo Akt Activation Counteract Cancer Cachexia by Inducing a Hypertrophic Profile through eIF-2α Modulation. Cancers (Basel) 2021; 14:cancers14010028. [PMID: 35008195 PMCID: PMC8750332 DOI: 10.3390/cancers14010028] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Revised: 12/14/2021] [Accepted: 12/17/2021] [Indexed: 01/15/2023] Open
Abstract
Simple Summary Chronic disease-related muscle atrophy is a serious public health problem since it reduces mobility and contributes to increases in hospitalization costs. Unfortunately, there is no approved treatment for muscle wasting at present. Thus, an understanding of the mechanisms underlying the control of muscle mass and function under chronic diseases can pave the way for the discovery of innovative therapeutic strategies to counteract muscle wasting. Since numerous types of cancer induce cachexia, which has no cure nor an effective treatment, the main proposal here was to study the effects of AET in cancer cachexia, and to investigate, through in vivo manipulation of the Akt/mTORC1 pathway, whether the cachectic muscle still presents conditions to respond adaptively to hypertrophic stimuli. Our results could provide a basis for innovative research lines to better understand muscle plasticity and to investigate potential therapeutic approaches necessary to prevent muscle loss. Abstract Cancer cachexia is a multifactorial and devastating syndrome characterized by severe skeletal muscle mass loss and dysfunction. As cachexia still has neither a cure nor an effective treatment, better understanding of skeletal muscle plasticity in the context of cancer is of great importance. Although aerobic exercise training (AET) has been shown as an important complementary therapy for chronic diseases and associated comorbidities, the impact of AET on skeletal muscle mass maintenance during cancer progression has not been well documented yet. Here, we show that previous AET induced a protective mechanism against tumor-induced muscle wasting by modulating the Akt/mTORC1 signaling and eukaryotic initiation factors, specifically eIF2-α. Thereafter, it was determined whether the in vivo Akt activation would induce a hypertrophic profile in cachectic muscles. As observed for the first time, Akt-induced hypertrophy was able and sufficient to either prevent or revert cancer cachexia by modulating both Akt/mTORC1 pathway and the eIF-2α activation, and induced a better muscle functionality. These findings provide evidence that skeletal muscle tissue still preserves hypertrophic potential to be stimulated by either AET or gene therapy to counteract cancer cachexia.
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Affiliation(s)
- Marcelo G. Pereira
- School of Physical Education and Sport, University of Sao Paulo, Sao Paulo 05508030, Brazil; (V.A.V.); (G.C.T.); (L.d.S.); (G.S.B.); (A.O.P.); (N.R.d.A.)
- Leeds School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK;
- Correspondence: (M.G.P.); (P.C.B.)
| | - Vanessa A. Voltarelli
- School of Physical Education and Sport, University of Sao Paulo, Sao Paulo 05508030, Brazil; (V.A.V.); (G.C.T.); (L.d.S.); (G.S.B.); (A.O.P.); (N.R.d.A.)
- Sirio-Libanes Hospital, Sao Paulo 01308050, Brazil
- Department of Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02115, USA
| | - Gabriel C. Tobias
- School of Physical Education and Sport, University of Sao Paulo, Sao Paulo 05508030, Brazil; (V.A.V.); (G.C.T.); (L.d.S.); (G.S.B.); (A.O.P.); (N.R.d.A.)
- Children’s Cancer and Blood Foundation Laboratories, Departments of Pediatrics, and Cell and Developmental Biology, Drukier Institute for Children’s Health, Meyer Cancer Center, Weill Cornell Medicine, New York, NY 10021, USA
| | - Lara de Souza
- School of Physical Education and Sport, University of Sao Paulo, Sao Paulo 05508030, Brazil; (V.A.V.); (G.C.T.); (L.d.S.); (G.S.B.); (A.O.P.); (N.R.d.A.)
| | - Gabriela S. Borges
- School of Physical Education and Sport, University of Sao Paulo, Sao Paulo 05508030, Brazil; (V.A.V.); (G.C.T.); (L.d.S.); (G.S.B.); (A.O.P.); (N.R.d.A.)
| | - Ailma O. Paixão
- School of Physical Education and Sport, University of Sao Paulo, Sao Paulo 05508030, Brazil; (V.A.V.); (G.C.T.); (L.d.S.); (G.S.B.); (A.O.P.); (N.R.d.A.)
| | - Ney R. de Almeida
- School of Physical Education and Sport, University of Sao Paulo, Sao Paulo 05508030, Brazil; (V.A.V.); (G.C.T.); (L.d.S.); (G.S.B.); (A.O.P.); (N.R.d.A.)
| | - Thomas Scott Bowen
- Leeds School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK;
| | - Marilene Demasi
- Biochemistry and Biophysics Laboratory, Butantan Institute, Sao Paulo 05503900, Brazil;
| | - Elen H. Miyabara
- Department of Anatomy, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo 05508000, Brazil;
| | - Patricia C. Brum
- School of Physical Education and Sport, University of Sao Paulo, Sao Paulo 05508030, Brazil; (V.A.V.); (G.C.T.); (L.d.S.); (G.S.B.); (A.O.P.); (N.R.d.A.)
- Correspondence: (M.G.P.); (P.C.B.)
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15
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Baraldo M, Nogara L, Dumitras GA, Tchampda Dondjang AH, Geremia A, Scalabrin M, Türk C, Telkamp F, Zentilin L, Giacca M, Krüger M, Blaauw B. Raptor is critical for increasing the mitochondrial proteome and skeletal muscle force during hypertrophy. FASEB J 2021; 35:e22031. [PMID: 34767636 DOI: 10.1096/fj.202101054rr] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Revised: 10/11/2021] [Accepted: 10/22/2021] [Indexed: 12/16/2022]
Abstract
Loss of skeletal muscle mass and force is of critical importance in numerous pathologies, like age-related sarcopenia or cancer. It has been shown that the Akt-mTORC1 pathway is critical for stimulating adult muscle mass and function, however, it is unknown if mTORC1 is the only mediator downstream of Akt and which intracellular processes are required for functional muscle growth. Here, we show that loss of Raptor reduces muscle hypertrophy after Akt activation and completely prevents increases in muscle force. Interestingly, the residual hypertrophy after Raptor deletion can be completely prevented by administration of the mTORC1 inhibitor rapamycin. Using a quantitative proteomics approach we find that loss of Raptor affects the increases in mitochondrial proteins, while rapamycin mainly affects ribosomal proteins. Taken together, these results suggest that mTORC1 is the key mediator of Akt-dependent muscle growth and its regulation of the mitochondrial proteome is critical for increasing muscle force.
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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
| | - Leonardo Nogara
- 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 Scalabrin
- 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), University of Cologne, Cologne, Germany
| | - Frederik Telkamp
- Institute for Genetics, Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
| | - Lorena Zentilin
- AAV Vector Unit, International Centre for Genetic Engineering and Biotechnology (ICGEB), Trieste, Italy
| | - Mauro Giacca
- School of Cardiovascular Medicine & Sciences, King's College London, British Heart Foundation Centre of Research Excellence, London, UK
| | - Marcus Krüger
- 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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16
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Borg ML, Massart J, De Castro Barbosa T, Archilla-Ortega A, Smith JAB, Lanner JT, Alsina-Fernandez J, Yaden B, Culver AE, Karlsson HKR, Brozinick JT, Zierath JR. Modified UCN2 peptide treatment improves skeletal muscle mass and function in mouse models of obesity-induced insulin resistance. J Cachexia Sarcopenia Muscle 2021; 12:1232-1248. [PMID: 34342159 PMCID: PMC8517345 DOI: 10.1002/jcsm.12746] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Revised: 05/25/2021] [Accepted: 06/08/2021] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Type 2 diabetes and obesity are often seen concurrently with skeletal muscle wasting, leading to further derangements in function and metabolism. Muscle wasting remains an unmet need for metabolic disease, and new approaches are warranted. The neuropeptide urocortin 2 (UCN2) and its receptor corticotropin releasing factor receptor 2 (CRHR2) are highly expressed in skeletal muscle and play a role in regulating energy balance, glucose metabolism, and muscle mass. The aim of this study was to investigate the effects of modified UCN2 peptides as a pharmaceutical therapy to counteract the loss of skeletal muscle mass associated with obesity and casting immobilization. METHODS High-fat-fed mice (C57Bl/6J; 26 weeks old) and ob/ob mice (11 weeks old) were injected daily with a PEGylated (Compound A) and non-PEGylated (Compound B) modified human UCN2 at 0.3 mg/kg subcutaneously for 14 days. A separate group of chow-fed C57Bl/6J mice (12 weeks old) was subjected to hindlimb cast immobilization and, after 1 week, received daily injections with Compound A. In vivo functional tests were performed to measure protein synthesis rates and skeletal muscle function. Ex vivo functional and molecular tests were performed to measure contractile force and signal transduction of catabolic and anabolic pathways in skeletal muscle. RESULTS Skeletal muscles (extensor digitorum longus, soleus, and tibialis anterior) from high-fat-fed mice treated with Compound A were ~14% heavier than muscles from vehicle-treated mice. Chronic treatment with modified UCN2 peptides altered the expression of structural genes and transcription factors in skeletal muscle in high-fat diet-induced obesity including down-regulation of Trim63 and up-regulation of Nr4a2 and Igf1 (P < 0.05 vs. vehicle). Signal transduction via both catabolic and anabolic pathways was increased in tibialis anterior muscle, with increased phosphorylation of ribosomal protein S6 at Ser235/236 , FOXO1 at Ser256 , and ULK1 at Ser317 , suggesting that UCN2 treatment modulates protein synthesis and degradation pathways (P < 0.05 vs. vehicle). Acutely, a single injection of Compound A in drug-naïve mice had no effect on the rate of protein synthesis in skeletal muscle, as measured via the surface sensing of translation method, while the expression of Nr4a3 and Ppargc1a4 was increased (P < 0.05 vs. vehicle). Compound A treatment prevented the loss of force production from disuse due to casting. Compound B treatment increased time to fatigue during ex vivo contractions of fast-twitch extensor digitorum longus muscle. Compound A and B treatment increased lean mass and rates of skeletal muscle protein synthesis in ob/ob mice. CONCLUSIONS Modified human UCN2 is a pharmacological candidate for the prevention of the loss of skeletal muscle mass associated with obesity and immobilization.
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Affiliation(s)
- Melissa L Borg
- Department of Physiology and Pharmacology, Section for Integrative Physiology, Karolinska Institutet, Stockholm, Sweden
| | - Julie Massart
- Department of Molecular Medicine and Surgery, Section for Integrative Physiology, Karolinska Institutet, Stockholm, Sweden
| | - Thais De Castro Barbosa
- Department of Physiology and Pharmacology, Section for Integrative Physiology, Karolinska Institutet, Stockholm, Sweden
| | - Adrià Archilla-Ortega
- Department of Physiology and Pharmacology, Section for Integrative Physiology, Karolinska Institutet, Stockholm, Sweden
| | - Jonathon A B Smith
- Department of Physiology and Pharmacology, Section for Integrative Physiology, Karolinska Institutet, Stockholm, Sweden
| | - Johanna T Lanner
- Department of Physiology and Pharmacology, Section for Molecular Muscle Physiology and Pathophysiology, Karolinska Institutet, Stockholm, Sweden
| | | | - Benjamin Yaden
- Lilly Research Laboratories, Division of Eli Lilly and Company, Indianapolis, IN, USA
| | - Alexander E Culver
- Lilly Research Laboratories, Division of Eli Lilly and Company, Indianapolis, IN, USA
| | - Håkan K R Karlsson
- Department of Molecular Medicine and Surgery, Section for Integrative Physiology, Karolinska Institutet, Stockholm, Sweden
| | - Joseph T Brozinick
- Lilly Research Laboratories, Division of Eli Lilly and Company, Indianapolis, IN, USA
| | - Juleen R Zierath
- Department of Physiology and Pharmacology, Section for Integrative Physiology, Karolinska Institutet, Stockholm, Sweden.,Department of Molecular Medicine and Surgery, Section for Integrative Physiology, Karolinska Institutet, Stockholm, Sweden
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17
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Murach KA, Fry CS, Dupont-Versteegden EE, McCarthy JJ, Peterson CA. Fusion and beyond: Satellite cell contributions to loading-induced skeletal muscle adaptation. FASEB J 2021; 35:e21893. [PMID: 34480776 PMCID: PMC9293230 DOI: 10.1096/fj.202101096r] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2021] [Revised: 08/13/2021] [Accepted: 08/17/2021] [Indexed: 12/14/2022]
Abstract
Satellite cells support adult skeletal muscle fiber adaptations to loading in numerous ways. The fusion of satellite cells, driven by cell-autonomous and/or extrinsic factors, contributes new myonuclei to muscle fibers, associates with load-induced hypertrophy, and may support focal membrane damage repair and long-term myonuclear transcriptional output. Recent studies have also revealed that satellite cells communicate within their niche to mediate muscle remodeling in response to resistance exercise, regulating the activity of numerous cell types through various mechanisms such as secretory signaling and cell-cell contact. Muscular adaptation to resistance and endurance activity can be initiated and sustained for a period of time in the absence of satellite cells, but satellite cell participation is ultimately required to achieve full adaptive potential, be it growth, function, or proprioceptive coordination. While significant progress has been made in understanding the roles of satellite cells in adult muscle over the last few decades, many conclusions have been extrapolated from regeneration studies. This review highlights our current understanding of satellite cell behavior and contributions to adaptation outside of regeneration in adult muscle, as well as the roles of satellite cells beyond fusion and myonuclear accretion, which are gaining broader recognition.
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Affiliation(s)
- Kevin A Murach
- The Center for Muscle Biology, University of Kentucky, Lexington, Kentucky, USA.,Molecular Muscle Mass Regulation Laboratory, Exercise Science Research Center, Department of Health, Human Performance, and Recreation, University of Arkansas, Fayetteville, Arkansas, USA.,Cell and Molecular Biology Program, University of Arkansas, Fayetteville, Arkansas, USA
| | - Christopher S Fry
- The Center for Muscle Biology, University of Kentucky, Lexington, Kentucky, USA.,Department of Athletic Training and Clinical Nutrition, College of Health Sciences, University of Kentucky, Lexington, Kentucky, USA
| | - Esther E Dupont-Versteegden
- The Center for Muscle Biology, University of Kentucky, Lexington, Kentucky, USA.,Department of Physical Therapy, College of Health Sciences, University of Kentucky, Lexington, Kentucky, USA
| | - John J McCarthy
- The Center for Muscle Biology, University of Kentucky, Lexington, Kentucky, USA.,Department of Physiology, College of Medicine, University of Kentucky, Lexington, Kentucky, USA
| | - Charlotte A Peterson
- The Center for Muscle Biology, University of Kentucky, Lexington, Kentucky, USA.,Department of Physical Therapy, College of Health Sciences, University of Kentucky, Lexington, Kentucky, USA.,Department of Physiology, College of Medicine, University of Kentucky, Lexington, Kentucky, USA
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18
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Miyazaki M, Moriya N, Takemasa T. Transient activation of mTORC1 signaling in skeletal muscle is independent of Akt1 regulation. Physiol Rep 2021; 8:e14599. [PMID: 33038070 PMCID: PMC7547586 DOI: 10.14814/phy2.14599] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2020] [Revised: 09/08/2020] [Accepted: 09/09/2020] [Indexed: 12/17/2022] Open
Abstract
The regulation of cellular protein synthesis is a critical determinant of skeletal muscle growth and hypertrophy in response to an increased workload such as resistance exercise. The mechanistic target of rapamycin complex 1 (mTORC1) and its upstream protein kinase Akt1 have been implicated as a central signaling pathway that regulates protein synthesis in the skeletal muscle; however, the precise molecular regulation of mTORC1 activity is largely unknown. This study employed germline Akt1 knockout (KO) mice to examine whether upstream Akt1 regulation is necessary for the acute activation of mTORC1 signaling in the plantaris muscle following mechanical overload. The phosphorylation states of S6 kinase 1, ribosomal protein S6, and eukaryotic translation initiation factor 4E‐binding protein 1 which show the functional activity of mTORC1 signaling, were significantly increased in the skeletal muscle of both wildtype and Akt1 KO mice following an acute bout (3 and 12 hr) of mechanical overload. Akt1 deficiency did not affect load‐induced alteration of insulin‐like growth factor‐1 (IGF‐1)/IGF receptor mRNA expression. Also, no effect of Akt1 deficiency was observed on the overload‐induced increase in the gene expressions of pax7 and myogenic regulatory factor of myogenin. These observations show that the upstream IGF‐1/Akt1 regulation is dispensable for the acute activation of mTORC1 signaling and regulation of satellite cells in response to mechanical overload.
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Affiliation(s)
- Mitsunori Miyazaki
- Department of Physical Therapy, School of Rehabilitation Sciences, Health Sciences University of Hokkaido, Hokkaido, Japan
| | - Nobuki Moriya
- Department of Physical Therapy, School of Rehabilitation Sciences, Health Sciences University of Hokkaido, Hokkaido, Japan.,Department of Rehabilitation, Faculty of Medical Science and Welfare, Tohoku Bunka Gakuen University, Miyagi, Japan
| | - Tohru Takemasa
- Graduate School of Comprehensive Human Sciences, University of Tsukuba, Ibaraki, Japan
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19
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Figueiredo VC, McCarthy JJ. Targeting cancer via ribosome biogenesis: the cachexia perspective. Cell Mol Life Sci 2021; 78:5775-5787. [PMID: 34196731 PMCID: PMC11072391 DOI: 10.1007/s00018-021-03888-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Revised: 06/03/2021] [Accepted: 06/18/2021] [Indexed: 12/14/2022]
Abstract
Cancer cachexia afflicts many advanced cancer patients with many progressing to death. While there have been many advancements in understanding the molecular mechanisms that contribute to the development of cancer cachexia, substantial gaps still exist. Chemotherapy drugs often target ribosome biogenesis to slow or blunt tumor cell growth and proliferation. Some of the most frequent side-effects of chemotherapy are loss of skeletal muscle mass, muscular strength and an increase in fatigue. Given that ribosome biogenesis has emerged as a main mechanism regulating muscle hypertrophy, and more recently, also implicated in muscle atrophy, we propose that some chemotherapy drugs can cause further muscle wasting via its effect on skeletal muscle cells. Many chemotherapy drugs, including the most prescribed drugs such as doxorubicin and cisplatin, affect ribosomal DNA transcription, or other pathways related to ribosome biogenesis. Furthermore, middle-aged and older individuals are the most affected population with cancer, and advanced cancer patients often show reduced levels of physical inactivity. Thus, aging and inactivity can themselves affect muscle ribosome biogenesis, which can further worsen the effect of chemotherapy on skeletal muscle ribosome biogenesis and, ultimately, muscle mass and function. We propose that chemotherapy can accelerate the onset or worsen cancer cachexia via its inhibitory effects on skeletal muscle ribosome biogenesis. We end our review by providing recommendations that could be used to ameliorate the negative effects of chemotherapy on skeletal muscle ribosome biogenesis.
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Affiliation(s)
- Vandré Casagrande Figueiredo
- College of Health Sciences, University of Kentucky, Lexington, KY, USA.
- Center for Muscle Biology, University of Kentucky, Lexington, KY, USA.
| | - John J McCarthy
- Department of Physiology, College of Medicine, University of Kentucky, Lexington, KY, USA
- Center for Muscle Biology, University of Kentucky, Lexington, KY, USA
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20
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Kopylov AT, Malsagova KA, Stepanov AA, Kaysheva AL. Diversity of Plant Sterols Metabolism: The Impact on Human Health, Sport, and Accumulation of Contaminating Sterols. Nutrients 2021; 13:nu13051623. [PMID: 34066075 PMCID: PMC8150896 DOI: 10.3390/nu13051623] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Revised: 05/05/2021] [Accepted: 05/08/2021] [Indexed: 02/07/2023] Open
Abstract
The way of plant sterols transformation and their benefits for humans is still a question under the massive continuing revision. In fact, there are no receptors for binding with sterols in mammalians. However, possible biotransformation to steroids that can be catalyzed by gastro-intestinal microflora, microbial cells in prebiotics or cytochromes system were repeatedly reported. Some products of sterols metabolization are capable to imitate resident human steroids and compete with them for the binding with corresponding receptors, thus affecting endocrine balance and entire physiology condition. There are also tremendous reports about the natural origination of mammalian steroid hormones in plants and corresponding receptors for their binding. Some investigations and reports warn about anabolic effect of sterols, however, there are many researchers who are reluctant to believe in and have strong opposing arguments. We encounter plant sterols everywhere: in food, in pharmacy, in cosmetics, but still know little about their diverse properties and, hence, their exact impact on our life. Most of our knowledge is limited to their cholesterol-lowering influence and protective effect against cardiovascular disease. However, the world of plant sterols is significantly wider if we consider the thousands of publications released over the past 10 years.
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21
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Prasad V, Millay DP. Skeletal muscle fibers count on nuclear numbers for growth. Semin Cell Dev Biol 2021; 119:3-10. [PMID: 33972174 DOI: 10.1016/j.semcdb.2021.04.015] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Revised: 03/30/2021] [Accepted: 04/19/2021] [Indexed: 02/06/2023]
Abstract
Skeletal muscle cells are noteworthy for their syncytial nature, with each myofiber accumulating hundreds or thousands of nuclei derived from resident muscle stem cells (MuSCs). These nuclei are accrued through cell fusion, which is controlled by the two essential fusogens Myomaker and Myomerger that are transiently expressed within the myogenic lineage. While the absolute requirement of fusion for muscle development has been known for decades, the underlying need for the magnitude of multinucleation in muscle remains mysterious. Possible advantages of multinucleation include the potential it affords for transcriptional diversity within these massive cells, and as a means of increasing DNA content to support optimal cell size and function. In this article, we review recent advances that elucidate the relationship between myonuclear numbers and establishment of myofiber size, and discuss how this new information refines our understanding of the concept of myonuclear domains (MND), the cytoplasmic volumes that each resident myonucleus can support. Finally, we explore the potential consequences and costs of multinucleation and its impacts on myonuclear transcriptional reserve capacity, growth potential, myofiber size regulation, and muscle adaptability. We anticipate this report will not only serve to highlight the latest advances in the basic biology of syncytial muscle cells but also provide information to help design the next generation of therapeutic strategies to maintain muscle mass and function.
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Affiliation(s)
- Vikram Prasad
- Division of Molecular Cardiovascular Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA
| | - Douglas P Millay
- Division of Molecular Cardiovascular Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA; Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH 45229, USA.
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22
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Moriscot A, Miyabara EH, Langeani B, Belli A, Egginton S, Bowen TS. Firearms-related skeletal muscle trauma: pathophysiology and novel approaches for regeneration. NPJ Regen Med 2021; 6:17. [PMID: 33772028 PMCID: PMC7997931 DOI: 10.1038/s41536-021-00127-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Accepted: 02/24/2021] [Indexed: 02/07/2023] Open
Abstract
One major cause of traumatic injury is firearm-related wounds (i.e., ballistic trauma), common in both civilian and military populations, which is increasing in prevalence and has serious long-term health and socioeconomic consequences worldwide. Common primary injuries of ballistic trauma include soft-tissue damage and loss, haemorrhage, bone fracture, and pain. The majority of injuries are of musculoskeletal origin and located in the extremities, such that skeletal muscle offers a major therapeutic target to aid recovery and return to normal daily activities. However, the underlying pathophysiology of skeletal muscle ballistic trauma remains poorly understood, with limited evidence-based treatment options. As such, this review will address the topic of firearm-related skeletal muscle injury and regeneration. We first introduce trauma ballistics and the immediate injury of skeletal muscle, followed by detailed coverage of the underlying biological mechanisms involved in regulating skeletal muscle dysfunction following injury, with a specific focus on the processes of muscle regeneration, muscle wasting and vascular impairments. Finally, we evaluate novel approaches for minimising muscle damage and enhancing muscle regeneration after ballistic trauma, which may have important relevance for primary care in victims of violence.
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Affiliation(s)
- Anselmo Moriscot
- Department of Anatomy, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Elen H Miyabara
- Department of Anatomy, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | | | - Antonio Belli
- NIHR Surgical Reconstruction and Microbiology Research Centre, University of Birmingham, Birmingham, UK
| | - Stuart Egginton
- School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, Leeds, UK
| | - T Scott Bowen
- School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, Leeds, UK.
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23
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Xia Q, Huang X, Huang J, Zheng Y, March ME, Li J, Wei Y. The Role of Autophagy in Skeletal Muscle Diseases. Front Physiol 2021; 12:638983. [PMID: 33841177 PMCID: PMC8027491 DOI: 10.3389/fphys.2021.638983] [Citation(s) in RCA: 49] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Accepted: 02/22/2021] [Indexed: 12/13/2022] Open
Abstract
Skeletal muscle is the most abundant type of tissue in human body, being involved in diverse activities and maintaining a finely tuned metabolic balance. Autophagy, characterized by the autophagosome–lysosome system with the involvement of evolutionarily conserved autophagy-related genes, is an important catabolic process and plays an essential role in energy generation and consumption, as well as substance turnover processes in skeletal muscles. Autophagy in skeletal muscles is finely tuned under the tight regulation of diverse signaling pathways, and the autophagy pathway has cross-talk with other pathways to form feedback loops under physiological conditions and metabolic stress. Altered autophagy activity characterized by either increased formation of autophagosomes or inhibition of lysosome-autophagosome fusion can lead to pathological cascades, and mutations in autophagy genes and deregulation of autophagy pathways have been identified as one of the major causes for a variety of skeleton muscle disorders. The advancement of multi-omics techniques enables further understanding of the molecular and biochemical mechanisms underlying the role of autophagy in skeletal muscle disorders, which may yield novel therapeutic targets for these disorders.
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Affiliation(s)
- Qianghua Xia
- Affiliated Cancer Hospital and Institute of Guangzhou Medical University, Guangzhou, China
| | - Xubo Huang
- Affiliated Cancer Hospital and Institute of Guangzhou Medical University, Guangzhou, China
| | - Jieru Huang
- Affiliated Cancer Hospital and Institute of Guangzhou Medical University, Guangzhou, China
| | - Yongfeng Zheng
- Affiliated Cancer Hospital and Institute of Guangzhou Medical University, Guangzhou, China
| | - Michael E March
- Center for Applied Genomics, The Children's Hospital of Philadelphia, Philadelphia, PA, United States
| | - Jin Li
- Affiliated Cancer Hospital and Institute of Guangzhou Medical University, Guangzhou, China
| | - Yongjie Wei
- Affiliated Cancer Hospital and Institute of Guangzhou Medical University, Guangzhou, China
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24
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Solsona R, Pavlin L, Bernardi H, Sanchez AMJ. Molecular Regulation of Skeletal Muscle Growth and Organelle Biosynthesis: Practical Recommendations for Exercise Training. Int J Mol Sci 2021; 22:2741. [PMID: 33800501 PMCID: PMC7962973 DOI: 10.3390/ijms22052741] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Revised: 03/04/2021] [Accepted: 03/04/2021] [Indexed: 12/18/2022] Open
Abstract
The regulation of skeletal muscle mass and organelle homeostasis is dependent on the capacity of cells to produce proteins and to recycle cytosolic portions. In this investigation, the mechanisms involved in skeletal muscle mass regulation-especially those associated with proteosynthesis and with the production of new organelles-are presented. Thus, the critical roles of mammalian/mechanistic target of rapamycin complex 1 (mTORC1) pathway and its regulators are reviewed. In addition, the importance of ribosome biogenesis, satellite cells involvement, myonuclear accretion, and some major epigenetic modifications related to protein synthesis are discussed. Furthermore, several studies conducted on the topic of exercise training have recognized the central role of both endurance and resistance exercise to reorganize sarcomeric proteins and to improve the capacity of cells to build efficient organelles. The molecular mechanisms underlying these adaptations to exercise training are presented throughout this review and practical recommendations for exercise prescription are provided. A better understanding of the aforementioned cellular pathways is essential for both healthy and sick people to avoid inefficient prescriptions and to improve muscle function with emergent strategies (e.g., hypoxic training). Finally, current limitations in the literature and further perspectives, notably on epigenetic mechanisms, are provided to encourage additional investigations on this topic.
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Affiliation(s)
- Robert Solsona
- Laboratoire Interdisciplinaire Performance Santé Environnement de Montagne (LIPSEM), Faculty of Sports Sciences, University of Perpignan Via Domitia, UR 4640, 7 Avenue Pierre de Coubertin, 66120 Font-Romeu, France;
| | - Laura Pavlin
- DMEM, University of Montpellier, INRAE UMR866, 2 Place Pierre Viala, 34060 Montpellier, France; (L.P.); (H.B.)
| | - Henri Bernardi
- DMEM, University of Montpellier, INRAE UMR866, 2 Place Pierre Viala, 34060 Montpellier, France; (L.P.); (H.B.)
| | - Anthony MJ Sanchez
- Laboratoire Interdisciplinaire Performance Santé Environnement de Montagne (LIPSEM), Faculty of Sports Sciences, University of Perpignan Via Domitia, UR 4640, 7 Avenue Pierre de Coubertin, 66120 Font-Romeu, France;
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25
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Costantini M, Testa S, Fornetti E, Fuoco C, Sanchez Riera C, Nie M, Bernardini S, Rainer A, Baldi J, Zoccali C, Biagini R, Castagnoli L, Vitiello L, Blaauw B, Seliktar D, Święszkowski W, Garstecki P, Takeuchi S, Cesareni G, Cannata S, Gargioli C. Biofabricating murine and human myo-substitutes for rapid volumetric muscle loss restoration. EMBO Mol Med 2021; 13:e12778. [PMID: 33587336 PMCID: PMC7933978 DOI: 10.15252/emmm.202012778] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Revised: 01/05/2021] [Accepted: 01/12/2021] [Indexed: 12/31/2022] Open
Abstract
The importance of skeletal muscle tissue is undoubted being the controller of several vital functions including respiration and all voluntary locomotion activities. However, its regenerative capability is limited and significant tissue loss often leads to a chronic pathologic condition known as volumetric muscle loss. Here, we propose a biofabrication approach to rapidly restore skeletal muscle mass, 3D histoarchitecture, and functionality. By recapitulating muscle anisotropic organization at the microscale level, we demonstrate to efficiently guide cell differentiation and myobundle formation both in vitro and in vivo. Of note, upon implantation, the biofabricated myo-substitutes support the formation of new blood vessels and neuromuscular junctions-pivotal aspects for cell survival and muscle contractile functionalities-together with an advanced muscle mass and force recovery. Altogether, these data represent a solid base for further testing the myo-substitutes in large animal size and a promising platform to be eventually translated into clinical scenarios.
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Affiliation(s)
- Marco Costantini
- Institute of Physical ChemistryPolish Academy of SciencesWarsawPoland
| | - Stefano Testa
- Department of BiologyRome University Tor VergataRomeItaly
| | | | - Claudia Fuoco
- Department of BiologyRome University Tor VergataRomeItaly
| | | | - Minghao Nie
- Department of Mechano‐InformaticsGraduate School of Information Science and TechnologyThe University of TokyoTokyoJapan
| | | | - Alberto Rainer
- Department of EngineeringUniversità Campus Bio‐Medico di RomaRomeItaly
- Institute of Nanotechnology (NANOTEC)National Research CouncilLecceItaly
| | - Jacopo Baldi
- IRCCS Regina Elena National Cancer InstituteRomeItaly
| | | | | | | | | | - Bert Blaauw
- Department of Biomedical Science and Venetian Institute of Molecular MedicineUniversity of PadovaPadovaItaly
| | - Dror Seliktar
- Department of Biomedical EngineeringTechion InstituteHaifaIsrael
| | - Wojciech Święszkowski
- Faculty of Materials Science and EngineeringWarsaw University of TechnologyWarsawPoland
| | - Piotr Garstecki
- Institute of Physical ChemistryPolish Academy of SciencesWarsawPoland
| | - Shoji Takeuchi
- Department of Mechano‐InformaticsGraduate School of Information Science and TechnologyThe University of TokyoTokyoJapan
- Institute of Industrial ScienceThe University of TokyoTokyoJapan
| | - Gianni Cesareni
- Department of BiologyRome University Tor VergataRomeItaly
- IRCCS Fondazione Santa LuciaRomeItaly
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26
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Crescioli C. Vitamin D Restores Skeletal Muscle Cell Remodeling and Myogenic Program: Potential Impact on Human Health. Int J Mol Sci 2021; 22:1760. [PMID: 33578813 PMCID: PMC7916580 DOI: 10.3390/ijms22041760] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Revised: 02/01/2021] [Accepted: 02/05/2021] [Indexed: 12/18/2022] Open
Abstract
Skeletal muscle cells, albeit classified as vitamin D receptor (VDR)-poor cells, are finely controlled by vitamin D through genomic and non-genomic mechanisms. Skeletal muscle constantly undergoes cell remodeling, a complex system under multilevel regulation, mainly orchestrated by the satellite niche in response to a variety of stimuli. Cell remodeling is not limited to satisfy reparative and hypertrophic needs, but, through myocyte transcriptome/proteome renewal, it warrants the adaptations necessary to maintain tissue integrity. While vitamin D insufficiency promotes cell maladaptation, restoring vitamin D levels can correct/enhance the myogenic program. Hence, vitamin D fortified foods or supplementation potentially represents the desired approach to limit or avoid muscle wasting and ameliorate health. Nevertheless, consensus on protocols for vitamin D measurement and supplementation is still lacking, due to the high variability of lab tests and of the levels required in different contexts (i.e., age, sex, heath status, lifestyle). This review aims to describe how vitamin D can orchestrate skeletal muscle cell remodeling and myogenic programming, after reviewing the main processes and cell populations involved in this important process, whose correct progress highly impacts on human health. Topics on vitamin D optimal levels, supplementation and blood determination, which are still under debate, will be addressed.
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Affiliation(s)
- Clara Crescioli
- Department of Movement, Human and Health Sciences, Section of Health Sciences, University of Rome "Foro Italico", Piazza L. de Bosis 6, 00135 Rome, Italy
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27
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Monti E, Toniolo L, Marcucci L, Bondì M, Martellato I, Šimunič B, Toninello P, Franchi MV, Narici MV, Reggiani C. Are muscle fibres of body builders intrinsically weaker? A comparison with single fibres of aged-matched controls. Acta Physiol (Oxf) 2021; 231:e13557. [PMID: 32921001 DOI: 10.1111/apha.13557] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Revised: 08/21/2020] [Accepted: 09/03/2020] [Indexed: 12/17/2022]
Abstract
AIM Skeletal muscles of Body Builders (BB) represent an interesting model to study muscle mass gains in response to high volume resistance training. It is debated whether muscle contractile performance improves in proportion to mass. Here, we aim to assess whether muscle hypertrophy does not occur at the expense of performance. METHODS Six BB and Six untrained controls (CTRL) were recruited. Cross-sectional area (CSA) and maximum voluntary contraction (MVC) of quadriceps femoris muscle (QF) and CSA and architecture of vastus lateralis (VL) were determined. Moreover, a biopsy was taken from VL mid-portion and single fibres were analysed. RESULTS QF CSA and MVC were 32% (n.s., P = .052) and 58% (P = .009) higher in BB than in CTRL, respectively. VL CSA was 37% higher in BB (P = .030). Fast 2A fibres CSA was 24% (P = .048) greater in BB than in CTRL, when determined in immunostained sections of biopsy samples. Single permeabilized fast fibres CSA was 37% (n.s., P = .052) higher in BB than in CTRL, and their force was slightly higher in BB (n.s.), while specific tension (P0 ) was 19% (P = .024) lower. The lower P0 was not explained either by lower myosin content or by impaired calcium diffusion. Conversely, the swelling caused by skinning-induced permeabilization was different and, when used to correct P0 , differences between populations disappeared. CONCLUSIONS The results show that high degree of muscle hypertrophy is not detrimental for force generation capacity, as increases in fibre size and force are strictly proportional once the differential swelling response is accounted for.
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Affiliation(s)
- Elena Monti
- Department of Biomedical Sciences University of Padova Padova Italy
| | - Luana Toniolo
- Department of Biomedical Sciences University of Padova Padova Italy
| | - Lorenzo Marcucci
- Department of Biomedical Sciences University of Padova Padova Italy
| | - Michela Bondì
- Department of Biomedical Sciences University of Padova Padova Italy
| | - Ivan Martellato
- Department of Biomedical Sciences University of Padova Padova Italy
| | - Bostjan Šimunič
- Science and Research Centre Koper Institute for Kinesiology Research Koper Slovenia
| | - Paolo Toninello
- Clinic of Plastic Surgery Padova University Hospital Padova Italy
| | | | - Marco V. Narici
- Department of Biomedical Sciences University of Padova Padova Italy
- Science and Research Centre Koper Institute for Kinesiology Research Koper Slovenia
- CIR‐MYO Myology Centre Department of Biomedical Sciences University of Padua Padova Italy
| | - Carlo Reggiani
- Department of Biomedical Sciences University of Padova Padova Italy
- Science and Research Centre Koper Institute for Kinesiology Research Koper Slovenia
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28
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Sartori R, Romanello V, Sandri M. Mechanisms of muscle atrophy and hypertrophy: implications in health and disease. Nat Commun 2021; 12:330. [PMID: 33436614 PMCID: PMC7803748 DOI: 10.1038/s41467-020-20123-1] [Citation(s) in RCA: 359] [Impact Index Per Article: 119.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Accepted: 11/16/2020] [Indexed: 02/07/2023] Open
Abstract
Skeletal muscle is the protein reservoir of our body and an important regulator of glucose and lipid homeostasis. Consequently, the growth or the loss of muscle mass can influence general metabolism, locomotion, eating and respiration. Therefore, it is not surprising that excessive muscle loss is a bad prognostic index of a variety of diseases ranging from cancer, organ failure, infections and unhealthy ageing. Muscle function is influenced by different quality systems that regulate the function of contractile proteins and organelles. These systems are controlled by transcriptional dependent programs that adapt muscle cells to environmental and nutritional clues. Mechanical, oxidative, nutritional and energy stresses, as well as growth factors or cytokines modulate signaling pathways that, ultimately, converge on protein and organelle turnover. Novel insights that control and orchestrate such complex network are continuously emerging and will be summarized in this review. Understanding the mechanisms that control muscle mass will provide therapeutic targets for the treatment of muscle loss in inherited and non-hereditary diseases and for the improvement of the quality of life during ageing. Loss of muscle mass is associated with ageing and with a number of diseases such as cancer. Here, the authors review the signaling pathways that modulate protein synthesis and degradation and gain or loss of muscle mass, and discuss therapeutic implications and future directions for the field.
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Affiliation(s)
- Roberta Sartori
- Department of Biomedical Sciences, University of Padova, via Ugo Bassi 58/b, 35121, Padova, Italy.,Veneto Institute of Molecular Medicine, via Orus 2, 35129, Padova, Italy
| | - Vanina Romanello
- Department of Biomedical Sciences, University of Padova, via Ugo Bassi 58/b, 35121, Padova, Italy. .,Veneto Institute of Molecular Medicine, via Orus 2, 35129, Padova, Italy.
| | - Marco Sandri
- Department of Biomedical Sciences, University of Padova, via Ugo Bassi 58/b, 35121, Padova, Italy. .,Veneto Institute of Molecular Medicine, via Orus 2, 35129, Padova, Italy. .,Myology Center, University of Padova, via Ugo Bassi 58/b, 35121, Padova, Italy. .,Department of Medicine, McGill University, Montreal, Canada.
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29
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Abstract
Skeletal muscle hypertrophy can be induced by hormones and growth factors acting directly as positive regulators of muscle growth or indirectly by neutralizing negative regulators, and by mechanical signals mediating the effect of resistance exercise. Muscle growth during hypertrophy is controlled at the translational level, through the stimulation of protein synthesis, and at the transcriptional level, through the activation of ribosomal RNAs and muscle-specific genes. mTORC1 has a central role in the regulation of both protein synthesis and ribosomal biogenesis. Several transcription factors and co-activators, including MEF2, SRF, PGC-1α4, and YAP promote the growth of the myofibers. Satellite cell proliferation and fusion is involved in some but not all muscle hypertrophy models.
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Affiliation(s)
| | - Carlo Reggiani
- Department of Biomedical Sciences, University of Padova, Italy
- Science and Research Centre Koper, Institute for Kinesiology Research, Koper, Slovenia
| | | | - Bert Blaauw
- Venetian Institute of Molecular Medicine, Padova, Italy
- Department of Biomedical Sciences, University of Padova, Italy
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30
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Englund DA, Figueiredo VC, Dungan CM, Murach KA, Peck BD, Petrosino JM, Brightwell CR, Dupont AM, Neal AC, Fry CS, Accornero F, McCarthy JJ, Peterson CA. Satellite Cell Depletion Disrupts Transcriptional Coordination and Muscle Adaptation to Exercise. FUNCTION 2020; 2:zqaa033. [PMID: 34109314 PMCID: PMC8179974 DOI: 10.1093/function/zqaa033] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Revised: 11/17/2020] [Accepted: 11/18/2020] [Indexed: 01/06/2023] Open
Abstract
Satellite cells are required for postnatal development, skeletal muscle regeneration across the lifespan, and skeletal muscle hypertrophy prior to maturity. Our group has aimed to address whether satellite cells are required for hypertrophic growth in mature skeletal muscle. Here, we generated a comprehensive characterization and transcriptome-wide profiling of skeletal muscle during adaptation to exercise in the presence or absence of satellite cells in order to identify distinct phenotypes and gene networks influenced by satellite cell content. We administered vehicle or tamoxifen to adult Pax7-DTA mice and subjected them to progressive weighted wheel running (PoWeR). We then performed immunohistochemical analysis and whole-muscle RNA-seq of vehicle (SC+) and tamoxifen-treated (SC-) mice. Further, we performed single myonuclear RNA-seq to provide detailed information on how satellite cell fusion affects myonuclear transcription. We show that while skeletal muscle can mount a robust hypertrophic response to PoWeR in the absence of satellite cells, growth, and adaptation are ultimately blunted. Transcriptional profiling reveals several gene networks key to muscle adaptation are altered in the absence of satellite cells.
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Affiliation(s)
- Davis A Englund
- Department of Physical Therapy, College of Health Sciences, University of Kentucky, Lexington, KY, USA
- Center for Muscle Biology, University of Kentucky, Lexington, KY, USA
| | - Vandré C Figueiredo
- Department of Physical Therapy, College of Health Sciences, University of Kentucky, Lexington, KY, USA
- Center for Muscle Biology, University of Kentucky, Lexington, KY, USA
| | - Cory M Dungan
- Department of Physical Therapy, College of Health Sciences, University of Kentucky, Lexington, KY, USA
- Center for Muscle Biology, University of Kentucky, Lexington, KY, USA
| | - Kevin A Murach
- Department of Physical Therapy, College of Health Sciences, University of Kentucky, Lexington, KY, USA
- Center for Muscle Biology, University of Kentucky, Lexington, KY, USA
| | - Bailey D Peck
- Department of Physical Therapy, College of Health Sciences, University of Kentucky, Lexington, KY, USA
- Center for Muscle Biology, University of Kentucky, Lexington, KY, USA
| | - Jennifer M Petrosino
- Department of Physiology and Cell Biology, Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH, USA
| | - Camille R Brightwell
- Center for Muscle Biology, University of Kentucky, Lexington, KY, USA
- Department of Athletic Training and Clinical Nutrition, University of Kentucky, Lexington, KY, USA
| | - Alec M Dupont
- Center for Muscle Biology, University of Kentucky, Lexington, KY, USA
| | - Ally C Neal
- Center for Muscle Biology, University of Kentucky, Lexington, KY, USA
| | - Christopher S Fry
- Center for Muscle Biology, University of Kentucky, Lexington, KY, USA
- Department of Athletic Training and Clinical Nutrition, University of Kentucky, Lexington, KY, USA
| | - Federica Accornero
- Department of Physiology and Cell Biology, Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH, USA
| | - John J McCarthy
- Center for Muscle Biology, University of Kentucky, Lexington, KY, USA
- Department of Physiology, College of Medicine, University of Kentucky, Lexington, KY, USA
| | - Charlotte A Peterson
- Department of Physical Therapy, College of Health Sciences, University of Kentucky, Lexington, KY, USA
- Center for Muscle Biology, University of Kentucky, Lexington, KY, USA
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Bidirectional myofiber transition through altering the photobiomodulation condition. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2020; 212:112041. [PMID: 33002778 DOI: 10.1016/j.jphotobiol.2020.112041] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Revised: 08/09/2020] [Accepted: 09/22/2020] [Indexed: 11/20/2022]
Abstract
Despite remarkable advancements in modern medicine, muscular atrophy remains as an unsolved problem. It is well known that pathological characteristics of different atrophy types could vary according to the pathophysiological causes. In fact, the lesion of atrophy is not always homogenously distributed but often predominantly evident in either fast or slow myofibers. As the focalization of the atrophic lesions, the existence and the functional impairment of each fast and slow progenitor/satellite cell (SC) are suspected though there are still controversies about this hypothesis. In this study, we isolated Pax7 positive (Pax7+ve) SCs from the tibia anterior (fast) and soleus (slow) muscles respectively and successfully demonstrated, for the first time, the difference between optimal exposure durations of photobiomodulation (PBM) which was known as low level laser irradiation (LLLI) in promoting proliferation of Pax7+ve SC which were acquired from fast and slow muscles respectively. Moreover, a hypertrophy-accompanied bidirectional change in myofiber composition with neuromuscular junction alteration, either from slow to fast or fast to slow, were achieved by applying different PBM durations. Simultaneously, PBM exhibited a synergistic effect with muscle exercise on the increase in myofiber size. Our data suggested the existence of at least two different populations of Pax7+ve SC which possess distinct sensitivities towards PBM. As our data revealed the capability of PBM in bidirectional changes of skeletal muscle composition and neuromuscular junction constitution thereby strengthen its contractility through altering the irradiation condition, we believe PBM showed the potential to be as a promising clinical treatment for muscular atrophy.
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Cisterna B, Sobolev AP, Costanzo M, Malatesta M, Zancanaro C. Combined Microscopic and Metabolomic Approach to Characterize the Skeletal Muscle Fiber of the Ts65Dn Mouse, A Model of Down Syndrome. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2020; 26:1014-1023. [PMID: 32867866 DOI: 10.1017/s143192762002437x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Down syndrome (DS) is a genetically based disease caused by triplication of chromosome 21. DS is characterized by severe muscle weakness associated with motor deficits; however, understanding the DS-associated skeletal muscle condition is limited. In this study, we used a combined methodological approach involving light and electron microscopy, as well as nuclear magnetic resonance spectroscopy metabolomics, to investigate morphology and composition of the quadriceps muscles in the Ts65Dn mouse, a model of DS, to identify structural and/or functional trisomy-associated alterations. Morphometric analysis demonstrated a larger size of myofibers in trisomic versus euploid mice; however, myofibrils were thinner and contained higher amounts of mitochondria and lipid droplets. In trisomic mice, magnetic resonance spectroscopy showed a tendency to an overall increase in muscle metabolites involved in protein synthesis. These data strongly suggest that in DS, a sarcoplasmic hypertrophy associated with myofibril loss characterizes quadriceps myofibers. In addition, large-sized mitochondria suggestive of impaired fission/fusion events, as well as metabolites modifications suggestive of decreased mitochondrial function, were found in the trisomic muscle. Albeit preliminary, the results provided by this novel approach consistently indicate structural and compositional alterations of the DS skeletal muscle, which are typical of early aging.
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Affiliation(s)
- Barbara Cisterna
- Anatomy and Histology Section, Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Strada Le Grazie 8, VeronaI-37134, Italy
| | - Anatoly P Sobolev
- Magnetic Resonance Laboratory "Annalaura Segre", Institute for Biological Systems, National Research Council, via Salaria km 29.300, Monterotondo, RomeI-00015, Italy
| | - Manuela Costanzo
- Anatomy and Histology Section, Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Strada Le Grazie 8, VeronaI-37134, Italy
| | - Manuela Malatesta
- Anatomy and Histology Section, Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Strada Le Grazie 8, VeronaI-37134, Italy
| | - Carlo Zancanaro
- Anatomy and Histology Section, Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Strada Le Grazie 8, VeronaI-37134, Italy
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Reggiani C, Schiaffino S. Muscle hypertrophy and muscle strength: dependent or independent variables? A provocative review. Eur J Transl Myol 2020; 30:9311. [PMID: 33117512 PMCID: PMC7582410 DOI: 10.4081/ejtm.2020.9311] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Accepted: 08/23/2020] [Indexed: 01/02/2023] Open
Abstract
The question whether the muscle hypertrophy induced by resistance training, hormone administration or genetic manipulation is accompanied by a proportional increase in muscle strength is still open. This review summarizes and analyses data obtained in human and rodent muscles in studies that have monitored in parallel changes in muscle size and changes in muscle force, measured in isometric contractions in vivo, in isolated muscles ex vivo (in rodents) and in single muscle fibers. Although a general positive relation exists among the two variables, a number of studies show a clear dissociation with increase of muscle size with no change or even decrease in strength and, vice versa, increase in strength without increase in size. The possible mechanisms of such dissociation, which involves neural motor control and/or cellular and molecular adaptations of muscle fibers, are briefly discussed.
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Affiliation(s)
- Carlo Reggiani
- Department of Biomedical Sciences of the University of Padova, Padova, Italy.,Science and Research Centre Koper, Institute for Kinesiology Research, Koper, Slovenia
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Solagna F, Nogara L, Dyar KA, Greulich F, Mir AA, Türk C, Bock T, Geremia A, Baraldo M, Sartori R, Farup J, Uhlenhaut H, Vissing K, Krüger M, Blaauw B. Exercise-dependent increases in protein synthesis are accompanied by chromatin modifications and increased MRTF-SRF signalling. Acta Physiol (Oxf) 2020; 230:e13496. [PMID: 32408395 PMCID: PMC7507144 DOI: 10.1111/apha.13496] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Revised: 05/06/2020] [Accepted: 05/06/2020] [Indexed: 12/13/2022]
Abstract
AIM Resistance exercise increases muscle mass over time. However, the early signalling events leading to muscle growth are not yet well-defined. Here, we aim to identify new signalling pathways important for muscle remodelling after exercise. METHODS We performed a phosphoproteomics screen after a single bout of exercise in mice. As an exercise model we used unilateral electrical stimulation in vivo and treadmill running. We analysed muscle biopsies from human subjects to verify if our findings in murine muscle also translate to exercise in humans. RESULTS We identified a new phosphorylation site on Myocardin-Related Transcription Factor B (MRTF-B), a co-activator of serum response factor (SRF). Phosphorylation of MRTF-B is required for its nuclear translocation after exercise and is accompanied by the transcription of the SRF target gene Fos. In addition, high-intensity exercise also remodels chromatin at specific SRF target gene loci through the phosphorylation of histone 3 on serine 10 in myonuclei of both mice and humans. Ablation of the MAP kinase member MSK1/2 is sufficient to prevent this histone phosphorylation, reduce induction of SRF-target genes, and prevent increases in protein synthesis after exercise. CONCLUSION Our results identify a new exercise signalling fingerprint in vivo, instrumental for exercise-induced protein synthesis and potentially muscle growth.
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Affiliation(s)
| | - Leonardo Nogara
- Venetian Institute of Molecular Medicine (VIMM) Padova Italy
- Department of Biomedical Sciences University of Padova Padova Italy
| | - Kenneth A. Dyar
- Molecular Endocrinology, Institute for Diabetes and Cancer (IDC) Helmholz Zentrum MunichHelmholtz Diabetes Center (HMGU) Munich Germany
| | - Franziska Greulich
- Molecular Endocrinology, Institute for Diabetes and Cancer (IDC) Helmholz Zentrum MunichHelmholtz Diabetes Center (HMGU) Munich Germany
| | - Ashfaq A. Mir
- Molecular Endocrinology, Institute for Diabetes and Cancer (IDC) Helmholz Zentrum MunichHelmholtz Diabetes Center (HMGU) Munich Germany
| | - Clara Türk
- Research laboratory for Biochemical Pathology Department of Clinical Medicine & Department of Biomedicine Aarhus University Aarhus Denmark
| | - Theresa Bock
- Research laboratory for Biochemical Pathology Department of Clinical Medicine & Department of Biomedicine Aarhus University Aarhus Denmark
| | - Alessia Geremia
- Venetian Institute of Molecular Medicine (VIMM) Padova Italy
- Department of Biomedical Sciences University of Padova Padova Italy
| | - Martina Baraldo
- Venetian Institute of Molecular Medicine (VIMM) Padova Italy
- Department of Biomedical Sciences University of Padova Padova Italy
| | - Roberta Sartori
- Venetian Institute of Molecular Medicine (VIMM) Padova Italy
- Department of Biomedical Sciences University of Padova Padova Italy
| | - Jean Farup
- Research laboratory for Biochemical Pathology Department of Clinical Medicine & Department of Biomedicine Aarhus University Aarhus Denmark
| | - Henriette Uhlenhaut
- Molecular Endocrinology, Institute for Diabetes and Cancer (IDC) Helmholz Zentrum MunichHelmholtz Diabetes Center (HMGU) Munich Germany
- Chair for Metabolic Programming TUM School of Life SciencesZIEL‐Institute for Food & Health Freising Germany
| | - Kristian Vissing
- Department of Public Health, Section for Sport Science Aarhus University Aarhus Denmark
| | - Marcus Krüger
- Institute for Genetics Cologne Excellence Cluster on Cellular Stress Responses in Aging‐Associated Diseases (CECAD)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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Effect of Quercetin on Dexamethasone-Induced C2C12 Skeletal Muscle Cell Injury. Molecules 2020; 25:molecules25143267. [PMID: 32709024 PMCID: PMC7397304 DOI: 10.3390/molecules25143267] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Revised: 07/09/2020] [Accepted: 07/15/2020] [Indexed: 01/09/2023] Open
Abstract
Glucocorticoids are widely used anti-inflammatory drugs in clinical settings. However, they can induce skeletal muscle atrophy by reducing fiber cross-sectional area and myofibrillar protein content. Studies have proven that antioxidants can improve glucocorticoid-induced skeletal muscle atrophy. Quercetin is a potent antioxidant flavonoid widely distributed in fruits and vegetables and has shown protective effects against dexamethasone-induced skeletal muscle atrophy. In this study, we demonstrated that dexamethasone significantly inhibited cell growth and induced cell apoptosis by stimulating hydroxyl free radical production in C2C12 skeletal muscle cells. Our results evidenced that quercetin increased C2C12 skeletal cell viability and exerted antiapoptotic effects on dexamethasone-treated C2C12 cells by regulating mitochondrial membrane potential (ΔΨm) and reducing oxidative species. Quercetin can protect against dexamethasone-induced muscle atrophy by regulating the Bax/Bcl-2 ratio at the protein level and abnormal ΔΨm, which leads to the suppression of apoptosis.
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36
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Masschelein E, D'Hulst G, Zvick J, Hinte L, Soro-Arnaiz I, Gorski T, von Meyenn F, Bar-Nur O, De Bock K. Exercise promotes satellite cell contribution to myofibers in a load-dependent manner. Skelet Muscle 2020; 10:21. [PMID: 32646489 PMCID: PMC7346400 DOI: 10.1186/s13395-020-00237-2] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Accepted: 06/15/2020] [Indexed: 01/07/2023] Open
Abstract
BACKGROUND Satellite cells (SCs) are required for muscle repair following injury and are involved in muscle remodeling upon muscular contractions. Exercise stimulates SC accumulation and myonuclear accretion. To what extent exercise training at different mechanical loads drive SC contribution to myonuclei however is unknown. RESULTS By performing SC fate tracing experiments, we show that 8 weeks of voluntary wheel running increased SC contribution to myofibers in mouse plantar flexor muscles in a load-dependent, but fiber type-independent manner. Increased SC fusion however was not exclusively linked to muscle hypertrophy as wheel running without external load substantially increased SC fusion in the absence of fiber hypertrophy. Due to nuclear propagation, nuclear fluorescent fate tracing mouse models were inadequate to quantify SC contribution to myonuclei. Ultimately, by performing fate tracing at the DNA level, we show that SC contribution mirrors myonuclear accretion during exercise. CONCLUSIONS Collectively, mechanical load during exercise independently promotes SC contribution to existing myofibers. Also, due to propagation of nuclear fluorescent reporter proteins, our data warrant caution for the use of existing reporter mouse models for the quantitative evaluation of satellite cell contribution to myonuclei.
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Affiliation(s)
- Evi Masschelein
- Department Health Sciences and Technology, Laboratory of Exercise and Health, Swiss Federal Institute of Technology (ETH) Zurich, Zurich, Switzerland
| | - Gommaar D'Hulst
- Department Health Sciences and Technology, Laboratory of Exercise and Health, Swiss Federal Institute of Technology (ETH) Zurich, Zurich, Switzerland
| | - Joel Zvick
- Department Health Sciences and Technology, Laboratory of Regenerative and Movement Biology, Swiss Federal Institute of Technology (ETH) Zurich, Zurich, Switzerland
| | - Laura Hinte
- Department Health Sciences and Technology, Laboratory of Nutrition and Metabolic Epigenetics, Swiss Federal Institute of Technology (ETH) Zurich, Zurich, Switzerland
| | - Inés Soro-Arnaiz
- Department Health Sciences and Technology, Laboratory of Exercise and Health, Swiss Federal Institute of Technology (ETH) Zurich, Zurich, Switzerland
| | - Tatiane Gorski
- Department Health Sciences and Technology, Laboratory of Exercise and Health, Swiss Federal Institute of Technology (ETH) Zurich, Zurich, Switzerland
| | - Ferdinand von Meyenn
- Department Health Sciences and Technology, Laboratory of Nutrition and Metabolic Epigenetics, Swiss Federal Institute of Technology (ETH) Zurich, Zurich, Switzerland
| | - Ori Bar-Nur
- Department Health Sciences and Technology, Laboratory of Regenerative and Movement Biology, Swiss Federal Institute of Technology (ETH) Zurich, Zurich, Switzerland
| | - Katrien De Bock
- Department Health Sciences and Technology, Laboratory of Exercise and Health, Swiss Federal Institute of Technology (ETH) Zurich, Zurich, Switzerland.
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37
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Murach KA, Vechetti IJ, Van Pelt DW, Crow SE, Dungan CM, Figueiredo VC, Kosmac K, Fu X, Richards CI, Fry CS, McCarthy JJ, Peterson CA. Fusion-Independent Satellite Cell Communication to Muscle Fibers During Load-Induced Hypertrophy. FUNCTION 2020; 1:zqaa009. [PMID: 32864621 PMCID: PMC7448100 DOI: 10.1093/function/zqaa009] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Revised: 06/29/2020] [Accepted: 06/29/2020] [Indexed: 01/06/2023] Open
Abstract
The "canonical" function of Pax7+ muscle stem cells (satellite cells) during hypertrophic growth of adult muscle fibers is myonuclear donation via fusion to support increased transcriptional output. In recent years, however, emerging evidence suggests that satellite cells play an important secretory role in promoting load-mediated growth. Utilizing genetically modified mouse models of delayed satellite cell fusion and in vivo extracellular vesicle (EV) tracking, we provide evidence for satellite cell communication to muscle fibers during hypertrophy. Myogenic progenitor cell-EV-mediated communication to myotubes in vitro influences extracellular matrix (ECM)-related gene expression, which is congruent with in vivo overload experiments involving satellite cell depletion, as well as in silico analyses. Satellite cell-derived EVs can transfer a Cre-induced, cytoplasmic-localized fluorescent reporter to muscle cells as well as microRNAs that regulate ECM genes such as matrix metalloproteinase 9 (Mmp9), which may facilitate growth. Delayed satellite cell fusion did not limit long-term load-induced muscle hypertrophy indicating that early fusion-independent communication from satellite cells to muscle fibers is an underappreciated aspect of satellite cell biology. We cannot exclude the possibility that satellite cell-mediated myonuclear accretion is necessary to maintain prolonged growth, specifically in the later phases of adaptation, but these data collectively highlight how EV delivery from satellite cells can directly contribute to mechanical load-induced muscle fiber hypertrophy, independent of cell fusion to the fiber.
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Affiliation(s)
- Kevin A Murach
- The Center for Muscle Biology, University of Kentucky, Lexington, KY 40536, USA
- Department of Physical Therapy, 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, Lexington, KY 40536, USA
| | - Douglas W Van Pelt
- The Center for Muscle Biology, University of Kentucky, Lexington, KY 40536, USA
- Department of Physical Therapy, College of Health Sciences, University of Kentucky, Lexington, KY 40536, USA
| | - Samuel E Crow
- The Center for Muscle Biology, University of Kentucky, Lexington, KY 40536, USA
- Department of Physical Therapy, College of Health Sciences, University of Kentucky, Lexington, KY 40536, USA
| | - Cory M Dungan
- The Center for Muscle Biology, University of Kentucky, Lexington, KY 40536, USA
- Department of Physical Therapy, College of Health Sciences, University of Kentucky, Lexington, KY 40536, USA
| | - Vandre C Figueiredo
- The Center for Muscle Biology, University of Kentucky, Lexington, KY 40536, USA
- Department of Physical Therapy, College of Health Sciences, University of Kentucky, Lexington, KY 40536, USA
| | - Kate Kosmac
- The Center for Muscle Biology, University of Kentucky, Lexington, KY 40536, USA
- Department of Physical Therapy, College of Health Sciences, University of Kentucky, Lexington, KY 40536, USA
| | - Xu Fu
- Department of Chemistry, College of Arts and Sciences, University of Kentucky, Lexington, KY 40536, USA
| | - Christopher I Richards
- Department of Chemistry, College of Arts and Sciences, University of Kentucky, Lexington, KY 40536, USA
| | - Christopher S Fry
- The Center for Muscle Biology, University of Kentucky, Lexington, KY 40536, USA
- Department of Athletic Training and Clinical Nutrition, 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, Lexington, KY 40536, USA
| | - Charlotte A Peterson
- The Center for Muscle Biology, University of Kentucky, Lexington, KY 40536, USA
- Department of Physical Therapy, College of Health Sciences, University of Kentucky, Lexington, KY 40536, USA
- Department of Physiology, College of Medicine, University of Kentucky, Lexington, KY 40536, USA
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Fukada SI, Akimoto T, Sotiropoulos A. Role of damage and management in muscle hypertrophy: Different behaviors of muscle stem cells in regeneration and hypertrophy. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2020; 1867:118742. [PMID: 32417255 DOI: 10.1016/j.bbamcr.2020.118742] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Revised: 05/07/2020] [Accepted: 05/12/2020] [Indexed: 12/12/2022]
Abstract
Skeletal muscle is a dynamic tissue with two unique abilities; one is its excellent regenerative ability, due to the activity of skeletal muscle-resident stem cells named muscle satellite cells (MuSCs); and the other is the adaptation of myofiber size in response to external stimulation, intrinsic factors, or physical activity, which is known as plasticity. Low physical activity and some disease conditions lead to the reduction of myofiber size, called atrophy, whereas hypertrophy refers to the increase in myofiber size induced by high physical activity or anabolic hormones/drugs. MuSCs are essential for generating new myofibers during regeneration and the increase in new myonuclei during hypertrophy; however, there has been little investigation of the molecular mechanisms underlying MuSC activation, proliferation, and differentiation during hypertrophy compared to those of regeneration. One reason is that 'degenerative damage' to myofibers during muscle injury or upon hypertrophy (especially overloaded muscle) is believed to trigger similar activation/proliferation of MuSCs. However, evidence suggests that degenerative damage of myofibers is not necessary for MuSC activation/proliferation during hypertrophy. When considering MuSC-based therapy for atrophy, including sarcopenia, it will be indispensable to elucidate MuSC behaviors in muscles that exhibit non-degenerative damage, because degenerated myofibers are not present in the atrophied muscles. In this review, we summarize recent findings concerning the relationship between MuSCs and hypertrophy, and discuss what remains to be discovered to inform the development and application of relevant treatments for muscle atrophy.
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Affiliation(s)
- So-Ichiro Fukada
- Project for Muscle Stem Cell Biology, Graduate School of Pharmaceutical Sciences, Osaka University, Osaka, Japan.
| | | | - Athanassia Sotiropoulos
- Institut National de la Santé et de la Recherche Médicale U1016, Institut Cochin, Paris, France
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Zhou H, Yuan D, Gao W, Tian J, Sun H, Yu S, Wang J, Sun L. Loss of high-temperature requirement protein A2 protease activity induces mitonuclear imbalance via differential regulation of mitochondrial biogenesis in sarcopenia. IUBMB Life 2020; 72:1659-1679. [PMID: 32353215 DOI: 10.1002/iub.2289] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Revised: 03/06/2020] [Accepted: 03/29/2020] [Indexed: 12/15/2022]
Abstract
Cellular homeostasis requires tight coordination between nucleus and mitochondria, organelles that each possesses their own genomes. Disrupted mitonuclear communication has been found to be implicated in many aging processes. However, little is known about mitonuclear signaling regulator in sarcopenia which is a major contributor to the risk of poor health-related quality of life, disability, and premature death in older people. High-temperature requirement protein A2 (HtrA2/Omi) is a mitochondrial protease and plays an important role in mitochondrial proteostasis. HtrA2mnd2(-/-) mice harboring protease-deficient HtrA2/Omi Ser276Cys missense mutants exhibit premature aging phenotype. Additionally, HtrA2/Omi has been established as a signaling regulator in nervous system and tumors. We therefore asked whether HtrA2/Omi participates in mitonuclear signaling regulation in muscle degeneration. Using motor functional, histological, and molecular biological methods, we characterized the phenotype of HtrA2mnd2(-/-) muscle. Furthermore, we isolated the gastrocnemius muscle of HtrA2mnd2(-/-) mice and determined expression of genes in mitochondrial unfolded protein response (UPRmt ), mitohormesis, electron transport chain (ETC), and mitochondrial biogenesis. Here, we showed that HtrA2/Omi protease deficiency induced denervation-independent skeletal muscle degeneration with sarcopenia phenotypes. Despite mitochondrial hypofunction, upregulation of UPRmt and mitohormesis-related genes and elevated total reactive oxygen species (ROS) production were not observed in HtrA2mnd2(-/-) mice, contrary to previous assumptions that loss of protease activity of HtrA2/Omi would lead to mitochondrial dysfunction as a result of proteostasis disturbance and ROS burst. Instead, we showed that HtrA2/Omi protease deficiency results in different changes between the expression of nuclear DNA- and mitochondrial DNA-encoded ETC subunits, which is in consistent with their transcription factors, nuclear respiratory factors 1 and 2, and coactivator peroxisome proliferator-activated receptor γ coactivator 1α. These results reveal that loss of HtrA2/Omi protease activity induces mitonuclear imbalance via differential regulation of mitochondrial biogenesis in sarcopenia. The novel mechanistic insights may be of importance in developing new therapeutic strategies for sarcopenia.
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Affiliation(s)
- Haohan Zhou
- Key Laboratory of Pathobiology, Ministry of Education, Department of Pathophysiology, College of Basic Medical Sciences, Jilin University, Changchun, China
| | - Danni Yuan
- Key Laboratory of Pathobiology, Ministry of Education, Department of Pathophysiology, College of Basic Medical Sciences, Jilin University, Changchun, China
| | - Weinan Gao
- Department of Orthopedics, Second Hospital, Jilin University, Changchun, China
| | - Jiayi Tian
- Department of Reproductive Medicine and Center for Prenatal Diagnosis, First Hospital, Jilin University, Changchun, China
| | - Hongyu Sun
- Key Laboratory of Pathobiology, Ministry of Education, Department of Pathophysiology, College of Basic Medical Sciences, Jilin University, Changchun, China
| | - Shuang Yu
- Department of Reproductive Medicine, Second Hospital, Jilin University, Changchun, China
| | - Jincheng Wang
- Department of Orthopedics, Second Hospital, Jilin University, Changchun, China
| | - Liankun Sun
- Key Laboratory of Pathobiology, Ministry of Education, Department of Pathophysiology, College of Basic Medical Sciences, Jilin University, Changchun, China
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40
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Maruyama Y, Ikeda C, Wakabayashi K, Ato S, Ogasawara R. High-intensity muscle contraction-mediated increases in Akt1 and Akt2 phosphorylation do not contribute to mTORC1 activation and muscle protein synthesis. J Appl Physiol (1985) 2020; 128:830-837. [DOI: 10.1152/japplphysiol.00578.2019] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
High-intensity muscle contraction (HiMC) is known to induce muscle protein synthesis, a process in which mechanistic target of rapamycin (mTOR) is reported to play a critical role. However, the mechanistic details have not been completely elucidated. Here, we investigated whether Akt plays a role in regulating HiMC-induced mTORC1 activation and muscle protein synthesis using a rodent model of resistance exercise and MK2206 (an Akt kinase inhibitor). The right gastrocnemius muscle of male C57BL/6J mice aged 10 wk was isometrically contracted via percutaneous electrical stimulation (100 Hz, 5 sets of 10 3-s contractions, 7-s rest between contractions, and 3-min rest between sets), while the left gastrocnemius muscle served as a control. Vehicle or MK2206 was injected intraperitoneally 6 h before contraction. MK2206 inhibited both resting and HiMC-induced phosphorylation of Akt1 Ser-473 and Akt2 Ser-474. MK2206 also inhibited the resting phosphorylation of p70S6K and 4E-BP1, which are downstream targets of mTORC1; however, it did not inhibit the HiMC-induced increase in phosphorylation of these targets. Similarly, MK2206 inhibited the resting muscle protein synthesis, but not the resistance exercise-induced muscle protein synthesis. On the basis of these observations, we conclude that although Akt2 regulates resting mTORC1 activity and muscle protein synthesis, HiMC-induced increases in mTORC1 activity and muscle protein synthesis are Akt-independent processes. NEW & NOTEWORTHY Akt is well known to be an upstream regulator of mechanistic target of rapamycin (mTOR) and has three isoforms in mammals, namely, Akt1, Akt2, and Akt3. We found that high-intensity muscle contraction (HiMC) increases Akt1 and Akt2 phosphorylation; however, HiMC-induced increases in mTORC1 activity and muscle protein synthesis are Akt-independent processes.
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Affiliation(s)
- Yuki Maruyama
- Department of Life Science and Applied Chemistry, Nagoya Institute of Technology, Nagoya, Japan
| | - Chisaki Ikeda
- Department of Life Science and Applied Chemistry, Nagoya Institute of Technology, Nagoya, Japan
| | - Koki Wakabayashi
- Department of Life Science and Applied Chemistry, Nagoya Institute of Technology, Nagoya, Japan
| | - Satoru Ato
- Department of Life Science and Applied Chemistry, Nagoya Institute of Technology, Nagoya, Japan
| | - Riki Ogasawara
- Department of Life Science and Applied Chemistry, Nagoya Institute of Technology, Nagoya, Japan
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Ham AS, Chojnowska K, Tintignac LA, Lin S, Schmidt A, Ham DJ, Sinnreich M, Rüegg MA. mTORC1 signalling is not essential for the maintenance of muscle mass and function in adult sedentary mice. J Cachexia Sarcopenia Muscle 2020; 11:259-273. [PMID: 31697050 PMCID: PMC7015237 DOI: 10.1002/jcsm.12505] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/09/2019] [Accepted: 09/09/2019] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND The balance between protein synthesis and degradation (proteostasis) is a determining factor for muscle size and function. Signalling via the mammalian target of rapamycin complex 1 (mTORC1) regulates proteostasis in skeletal muscle by affecting protein synthesis and autophagosomal protein degradation. Indeed, genetic inactivation of mTORC1 in developing and growing muscle causes atrophy resulting in a lethal myopathy. However, systemic dampening of mTORC1 signalling by its allosteric inhibitor rapamycin is beneficial at the organismal level and increases lifespan. Whether the beneficial effect of rapamycin comes at the expense of muscle mass and function is yet to be established. METHODS We conditionally ablated the gene coding for the mTORC1-essential component raptor in muscle fibres of adult mice [inducible raptor muscle-specific knockout (iRAmKO)]. We performed detailed phenotypic and biochemical analyses of iRAmKO mice and compared them with muscle-specific raptor knockout (RAmKO) mice, which lack raptor in developing muscle fibres. We also used polysome profiling and proteomics to assess protein translation and associated signalling in skeletal muscle of iRAmKO mice. RESULTS Analysis at different time points reveal that, as in RAmKO mice, the proportion of oxidative fibres decreases, but slow-type fibres increase in iRAmKO mice. Nevertheless, no significant decrease in body and muscle mass or muscle fibre area was detected up to 5 months post-raptor depletion. Similarly, ex vivo muscle force was not significantly reduced in iRAmKO mice. Despite stable muscle size and function, inducible raptor depletion significantly reduced the expression of key components of the translation machinery and overall translation rates. CONCLUSIONS Raptor depletion and hence complete inhibition of mTORC1 signalling in fully grown muscle leads to metabolic and morphological changes without inducing muscle atrophy even after 5 months. Together, our data indicate that maintenance of muscle size does not require mTORC1 signalling, suggesting that rapamycin treatment is unlikely to negatively affect muscle mass and function.
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Affiliation(s)
| | | | - Lionel A Tintignac
- Department of Biomedicine, Pharmazentrum, University of Basel, Basel, Switzerland
| | - Shuo Lin
- Biozentrum, University of Basel, Basel, Switzerland
| | - Alexander Schmidt
- Proteomics Core Facility, Biozentrum, University of Basel, Basel, Switzerland
| | - Daniel J Ham
- Biozentrum, University of Basel, Basel, Switzerland
| | - Michael Sinnreich
- Department of Biomedicine, Pharmazentrum, University of Basel, Basel, Switzerland
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42
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Beiter T, Nieß AM, Moser D. Transcriptional memory in skeletal muscle. Don't forget (to) exercise. J Cell Physiol 2020; 235:5476-5489. [PMID: 31967338 DOI: 10.1002/jcp.29535] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Accepted: 01/09/2020] [Indexed: 12/29/2022]
Abstract
Transcriptional memory describes an ancient and highly conserved form of cellular learning that enables cells to benefit from recent experience by retaining a mitotically inheritable but reversible memory of the initial transcriptional response when encountering an environmental or physiological stimulus. Herein, we will review recent progress made in the understanding of how cells can make use of diverse constituents of the epigenetic toolbox to retain a transcriptional memory of past states and perturbations. Specifically, we will outline how these mechanisms will help to improve our understanding of skeletal muscle plasticity in health and disease. We describe the epigenetic road map that allows skeletal muscle fibers to navigate through training-induced adaptation processes, and how epigenetic memory marks can preserve an autobiographical history of lifestyle behavior changes, pathological challenges, and aging. We will further consider some key findings in the field of exercise epigenomics to emphasize major challenges when interpreting dynamic changes in the chromatin landscape in response to acute exercise and training.
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Affiliation(s)
- Thomas Beiter
- Department of Sports Medicine, University Hospital Tübingen, Tübingen, Germany
| | - Andreas M Nieß
- Department of Sports Medicine, University Hospital Tübingen, Tübingen, Germany
| | - Dirk Moser
- Department of Genetic Psychology, Faculty of Psychology, Ruhr-University Bochum, Bochum, Germany
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43
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Tan KT, Ang STJ, Tsai SY. Sarcopenia: Tilting the Balance of Protein Homeostasis. Proteomics 2019; 20:e1800411. [PMID: 31722440 DOI: 10.1002/pmic.201800411] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Revised: 11/04/2019] [Indexed: 12/14/2022]
Abstract
Sarcopenia, defined as age-associated decline of muscle mass and function, is a risk factor for mortality and disability, and comorbid with several chronic diseases such as type II diabetes and cardiovascular diseases. Clinical trials showed that nutritional supplements had positive effects on muscle mass, but not on muscle function and strength, demonstrating our limited understanding of the molecular events involved in the ageing muscle. Protein homeostasis, the equilibrium between protein synthesis and degradation, is proposed as the major mechanism underlying the development of sarcopenia. As the key central regulator of protein homeostasis, the mammalian target of rapamycin (mTOR) is proposed to be essential for muscle hypertrophy. Paradoxically, sustained activation of mTOR complex 1 (mTORC1) is associated with a loss of sensitivity to extracellular signaling in the elderly. It is not understood why sustained mTORC1 activity, which should induce muscle hypertrophy, instead results in muscle atrophy. Here, recent findings on the implications of disrupting protein homeostasis on muscle physiology and sarcopenia development in the context of mTOR/protein kinase B (AKT) signaling are reviewed. Understanding the role of these molecular mechanisms during the ageing process will contribute towards the development of targeted therapies that will improve protein metabolism and reduce sarcopenia.
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Affiliation(s)
- Kuan Ting Tan
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, 2 Medical Drive, MD9 Admin Office, Singapore, 117597, Singapore
| | - Seok-Ting Jamie Ang
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, 2 Medical Drive, MD9 Admin Office, Singapore, 117597, Singapore
| | - Shih-Yin Tsai
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, 2 Medical Drive, MD9 Admin Office, Singapore, 117597, Singapore
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44
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Ruparelia AA, Ratnayake D, Currie PD. Stem cells in skeletal muscle growth and regeneration in amniotes and teleosts: Emerging themes. WILEY INTERDISCIPLINARY REVIEWS-DEVELOPMENTAL BIOLOGY 2019; 9:e365. [PMID: 31743958 DOI: 10.1002/wdev.365] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Revised: 09/22/2019] [Accepted: 10/03/2019] [Indexed: 12/19/2022]
Abstract
Skeletal muscle is a contractile, postmitotic tissue that retains the capacity to grow and regenerate throughout life in amniotes and teleost. Both muscle growth and regeneration are regulated by obligate tissue resident muscle stem cells. Given that considerable knowledge exists on the myogenic process, recent studies have focused on examining the molecular markers of muscle stem cells, and on the intrinsic and extrinsic signals regulating their function. From this, two themes emerge: firstly, muscle stem cells display remarkable heterogeneity not only with regards to their gene expression profile, but also with respect to their behavior and function; and secondly, the stem cell niche is a critical regulator of muscle stem cell function during growth and regeneration. Here, we will address the current understanding of these emerging themes with emphasis on the distinct processes used by amniotes and teleost, and discuss the challenges and opportunities in the muscle growth and regeneration fields. This article is characterized under: Adult Stem Cells, Tissue Renewal, and Regeneration > Tissue Stem Cells and Niches Early Embryonic Development > Development to the Basic Body Plan Vertebrate Organogenesis > Musculoskeletal and Vascular.
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Affiliation(s)
- Avnika A Ruparelia
- Australian Regenerative Medicine Institute, Monash University, Melbourne, Victoria, Australia.,EMBL Australia, Monash University, Melbourne, Victoria, Australia
| | - Dhanushika Ratnayake
- Australian Regenerative Medicine Institute, Monash University, Melbourne, Victoria, Australia.,EMBL Australia, Monash University, Melbourne, Victoria, Australia
| | - Peter D Currie
- Australian Regenerative Medicine Institute, Monash University, Melbourne, Victoria, Australia.,EMBL Australia, Monash University, Melbourne, Victoria, Australia
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45
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Ferreira DMS, Cheng AJ, Agudelo LZ, Cervenka I, Chaillou T, Correia JC, Porsmyr-Palmertz M, Izadi M, Hansson A, Martínez-Redondo V, Valente-Silva P, Pettersson-Klein AT, Estall JL, Robinson MM, Nair KS, Lanner JT, Ruas JL. LIM and cysteine-rich domains 1 (LMCD1) regulates skeletal muscle hypertrophy, calcium handling, and force. Skelet Muscle 2019; 9:26. [PMID: 31666122 PMCID: PMC6822430 DOI: 10.1186/s13395-019-0214-1] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Accepted: 09/30/2019] [Indexed: 12/27/2022] Open
Abstract
BACKGROUND Skeletal muscle mass and strength are crucial determinants of health. Muscle mass loss is associated with weakness, fatigue, and insulin resistance. In fact, it is predicted that controlling muscle atrophy can reduce morbidity and mortality associated with diseases such as cancer cachexia and sarcopenia. METHODS We analyzed gene expression data from muscle of mice or human patients with diverse muscle pathologies and identified LMCD1 as a gene strongly associated with skeletal muscle function. We transiently expressed or silenced LMCD1 in mouse gastrocnemius muscle or in mouse primary muscle cells and determined muscle/cell size, targeted gene expression, kinase activity with kinase arrays, protein immunoblotting, and protein synthesis levels. To evaluate force, calcium handling, and fatigue, we transduced the flexor digitorum brevis muscle with a LMCD1-expressing adenovirus and measured specific force and sarcoplasmic reticulum Ca2+ release in individual fibers. Finally, to explore the relationship between LMCD1 and calcineurin, we ectopically expressed Lmcd1 in the gastrocnemius muscle and treated those mice with cyclosporine A (calcineurin inhibitor). In addition, we used a luciferase reporter construct containing the myoregulin gene promoter to confirm the role of a LMCD1-calcineurin-myoregulin axis in skeletal muscle mass control and calcium handling. RESULTS Here, we identify LIM and cysteine-rich domains 1 (LMCD1) as a positive regulator of muscle mass, that increases muscle protein synthesis and fiber size. LMCD1 expression in vivo was sufficient to increase specific force with lower requirement for calcium handling and to reduce muscle fatigue. Conversely, silencing LMCD1 expression impairs calcium handling and force, and induces muscle fatigue without overt atrophy. The actions of LMCD1 were dependent on calcineurin, as its inhibition using cyclosporine A reverted the observed hypertrophic phenotype. Finally, we determined that LMCD1 represses the expression of myoregulin, a known negative regulator of muscle performance. Interestingly, we observed that skeletal muscle LMCD1 expression is reduced in patients with skeletal muscle disease. CONCLUSIONS Our gain- and loss-of-function studies show that LMCD1 controls protein synthesis, muscle fiber size, specific force, Ca2+ handling, and fatigue resistance. This work uncovers a novel role for LMCD1 in the regulation of skeletal muscle mass and function with potential therapeutic implications.
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Affiliation(s)
- Duarte M S Ferreira
- Molecular & Cellular Exercise Physiology, Department of Physiology and Pharmacology, Karolinska Institutet, Biomedicum, SE-171 77, Stockholm, Sweden
| | - Arthur J Cheng
- Molecular Muscle Physiology and Pathophysiology, Department of Physiology and Pharmacology, Karolinska Institutet, Biomedicum, SE-171 77, Stockholm, Sweden.,Present Address: Faculty of Health, York University, School of Kinesiology and Health Science, Toronto, Ontario, Canada
| | - Leandro Z Agudelo
- Molecular & Cellular Exercise Physiology, Department of Physiology and Pharmacology, Karolinska Institutet, Biomedicum, SE-171 77, Stockholm, Sweden.,Present Address: Computer Science and Artificial Intelligence Laboratory, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Igor Cervenka
- Molecular & Cellular Exercise Physiology, Department of Physiology and Pharmacology, Karolinska Institutet, Biomedicum, SE-171 77, Stockholm, Sweden
| | - Thomas Chaillou
- Molecular Muscle Physiology and Pathophysiology, Department of Physiology and Pharmacology, Karolinska Institutet, Biomedicum, SE-171 77, Stockholm, Sweden.,School of Health Sciences, Örebro University, Örebro, Sweden
| | - Jorge C Correia
- Molecular & Cellular Exercise Physiology, Department of Physiology and Pharmacology, Karolinska Institutet, Biomedicum, SE-171 77, Stockholm, Sweden
| | - Margareta Porsmyr-Palmertz
- Molecular & Cellular Exercise Physiology, Department of Physiology and Pharmacology, Karolinska Institutet, Biomedicum, SE-171 77, Stockholm, Sweden
| | - Manizheh Izadi
- Molecular & Cellular Exercise Physiology, Department of Physiology and Pharmacology, Karolinska Institutet, Biomedicum, SE-171 77, Stockholm, Sweden.,Present Address: Karp Research Building, Boston, MA, 02115, USA
| | - Alicia Hansson
- Molecular & Cellular Exercise Physiology, Department of Physiology and Pharmacology, Karolinska Institutet, Biomedicum, SE-171 77, Stockholm, Sweden
| | - Vicente Martínez-Redondo
- Molecular & Cellular Exercise Physiology, Department of Physiology and Pharmacology, Karolinska Institutet, Biomedicum, SE-171 77, Stockholm, Sweden
| | - Paula Valente-Silva
- Molecular & Cellular Exercise Physiology, Department of Physiology and Pharmacology, Karolinska Institutet, Biomedicum, SE-171 77, Stockholm, Sweden
| | - Amanda T Pettersson-Klein
- Molecular & Cellular Exercise Physiology, Department of Physiology and Pharmacology, Karolinska Institutet, Biomedicum, SE-171 77, Stockholm, Sweden
| | - Jennifer L Estall
- Division of Cardiovascular and Metabolic Disease, Institut de recherches cliniques de Montreal (IRCM), Montreal, QC, Canada
| | - Matthew M Robinson
- Division of Endocrinology, Diabetes and Nutrition, Mayo Clinic, Rochester, MN, 55905, USA
| | - K Sreekumaran Nair
- Division of Endocrinology, Diabetes and Nutrition, Mayo Clinic, Rochester, MN, 55905, USA
| | - Johanna T Lanner
- Molecular Muscle Physiology and Pathophysiology, Department of Physiology and Pharmacology, Karolinska Institutet, Biomedicum, SE-171 77, Stockholm, Sweden
| | - Jorge L Ruas
- Molecular & Cellular Exercise Physiology, Department of Physiology and Pharmacology, Karolinska Institutet, Biomedicum, SE-171 77, Stockholm, Sweden.
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Skeletal Muscle-Specific Methyltransferase METTL21C Trimethylates p97 and Regulates Autophagy-Associated Protein Breakdown. Cell Rep 2019; 23:1342-1356. [PMID: 29719249 DOI: 10.1016/j.celrep.2018.03.136] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Revised: 03/02/2018] [Accepted: 03/29/2018] [Indexed: 01/04/2023] Open
Abstract
Protein aggregates and cytoplasmic vacuolization are major hallmarks of multisystem proteinopathies (MSPs) that lead to muscle weakness. Here, we identify METTL21C as a skeletal muscle-specific lysine methyltransferase. Insertion of a β-galactosidase cassette into the Mettl21c mouse locus revealed that METTL21C is specifically expressed in MYH7-positive skeletal muscle fibers. Ablation of the Mettl21c gene reduced endurance capacity and led to age-dependent accumulation of autophagic vacuoles in skeletal muscle. Denervation-induced muscle atrophy highlighted further impairments of autophagy-related proteins, including LC3, p62, and cathepsins, in Mettl21c-/- muscles. In addition, we demonstrate that METTL21C interacts with the ATPase p97 (VCP), which is mutated in various human MSP conditions. We reveal that METTL21C trimethylates p97 on the Lys315 residue and found that loss of this modification reduced p97 hexamer formation and ATPase activity in vivo. We conclude that the methyltransferase METTL21C is an important modulator of protein degradation in skeletal muscle under both normal and enhanced protein breakdown conditions.
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47
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Englund DA, Peck BD, Murach KA, Neal AC, Caldwell HA, McCarthy JJ, Peterson CA, Dupont-Versteegden EE. Resident muscle stem cells are not required for testosterone-induced skeletal muscle hypertrophy. Am J Physiol Cell Physiol 2019; 317:C719-C724. [PMID: 31314585 PMCID: PMC6851003 DOI: 10.1152/ajpcell.00260.2019] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Revised: 07/16/2019] [Accepted: 07/16/2019] [Indexed: 02/06/2023]
Abstract
It is postulated that testosterone-induced skeletal muscle hypertrophy is driven by myonuclear accretion as the result of satellite cell fusion. To directly test this hypothesis, we utilized the Pax7-DTA mouse model to deplete satellite cells in skeletal muscle followed by testosterone administration. Pax7-DTA mice (6 mo of age) were treated for 5 days with either vehicle [satellite cell replete (SC+)] or tamoxifen [satellite cell depleted (SC-)]. Following a washout period, a testosterone propionate or sham pellet was implanted for 21 days. Testosterone administration caused a significant increase in muscle fiber cross-sectional area in SC+ and SC- mice in both oxidative (soleus) and glycolytic (plantaris and extensor digitorum longus) muscles. In SC+ mice treated with testosterone, there was a significant increase in both satellite cell abundance and myonuclei that was completely absent in testosterone-treated SC- mice. These findings provide direct evidence that testosterone-induced muscle fiber hypertrophy does not require an increase in satellite cell abundance or myonuclear accretion.Listen to a podcast about this Rapid Report with senior author E. E. Dupont-Versteegden (https://ajpcell.podbean.com/e/podcast-on-paper-that-shows-testosterone-induced-skeletal-muscle-hypertrophy-does-not-need-muscle-stem-cells/).
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Affiliation(s)
- Davis A Englund
- Department of Rehabilitation Sciences, College of Health Sciences, University of Kentucky, Lexington, Kentucky
- Center for Muscle Biology, University of Kentucky, Lexington, Kentucky
| | - Bailey D Peck
- Department of Rehabilitation Sciences, College of Health Sciences, University of Kentucky, Lexington, Kentucky
- Center for Muscle Biology, University of Kentucky, Lexington, Kentucky
| | - Kevin A Murach
- Department of Rehabilitation Sciences, College of Health Sciences, University of Kentucky, Lexington, Kentucky
- Center for Muscle Biology, University of Kentucky, Lexington, Kentucky
| | - Ally C Neal
- Center for Muscle Biology, University of Kentucky, Lexington, Kentucky
| | - Hannah A Caldwell
- Center for Muscle Biology, University of Kentucky, Lexington, Kentucky
| | - John J McCarthy
- Center for Muscle Biology, University of Kentucky, Lexington, Kentucky
- Department of Physiology, College of Medicine, University of Kentucky, Lexington, Kentucky
| | - Charlotte A Peterson
- Department of Rehabilitation Sciences, College of Health Sciences, University of Kentucky, Lexington, Kentucky
- Center for Muscle Biology, University of Kentucky, Lexington, Kentucky
| | - Esther E Dupont-Versteegden
- Department of Rehabilitation Sciences, College of Health Sciences, University of Kentucky, Lexington, Kentucky
- Center for Muscle Biology, University of Kentucky, Lexington, Kentucky
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48
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Inhibition of the Fission Machinery Mitigates OPA1 Impairment in Adult Skeletal Muscles. Cells 2019; 8:cells8060597. [PMID: 31208084 PMCID: PMC6627087 DOI: 10.3390/cells8060597] [Citation(s) in RCA: 59] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Revised: 05/29/2019] [Accepted: 06/07/2019] [Indexed: 12/16/2022] Open
Abstract
The maintenance of muscle mass and its ability to function relies on a bioenergetic efficient mitochondrial network. This network is highly impacted by fusion and fission events. We have recently shown that the acute deletion of the fusion protein Opa1 induces muscle atrophy, systemic inflammatory response, precocious epithelial senescence, and premature death that are caused by muscle-dependent secretion of FGF21. However, both fusion and fission machinery are suppressed in aging sarcopenia, cancer cachexia, and chemotherapy-induced muscle wasting. We generated inducible muscle-specific Opa1 and Drp1 double-knockout mice to address the physiological relevance of the concomitant impairment of fusion and fission machinery in skeletal muscle. Here we show that acute ablation of Opa1 and Drp1 in adult muscle causes the accumulation of abnormal and dysfunctional mitochondria, as well as the inhibition of autophagy and mitophagy pathways. This ultimately results in ER stress, muscle loss, and the reduction of force generation. However, the simultaneous inhibition of the fission protein Drp1 when Opa1 is absent alleviates FGF21 induction, oxidative stress, denervation, and inflammation rescuing the lethal phenotype of Opa1 knockout mice, despite the presence of any muscle weakness. Thus, the simultaneous inhibition of fusion and fission processes mitigates the detrimental effects of unbalanced mitochondrial fusion and prevents the secretion of pro-senescence factors.
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49
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DRP1-mediated mitochondrial shape controls calcium homeostasis and muscle mass. Nat Commun 2019; 10:2576. [PMID: 31189900 PMCID: PMC6561930 DOI: 10.1038/s41467-019-10226-9] [Citation(s) in RCA: 259] [Impact Index Per Article: 51.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2017] [Accepted: 04/23/2019] [Indexed: 12/18/2022] Open
Abstract
Mitochondrial quality control is essential in highly structured cells such as neurons and muscles. In skeletal muscle the mitochondrial fission proteins are reduced in different physiopathological conditions including ageing sarcopenia, cancer cachexia and chemotherapy-induced muscle wasting. However, whether mitochondrial fission is essential for muscle homeostasis is still unclear. Here we show that muscle-specific loss of the pro-fission dynamin related protein (DRP) 1 induces muscle wasting and weakness. Constitutive Drp1 ablation in muscles reduces growth and causes animal death while inducible deletion results in atrophy and degeneration. Drp1 deficient mitochondria are morphologically bigger and functionally abnormal. The dysfunctional mitochondria signals to the nucleus to induce the ubiquitin-proteasome system and an Unfolded Protein Response while the change of mitochondrial volume results in an increase of mitochondrial Ca2+ uptake and myofiber death. Our findings reveal that morphology of mitochondrial network is critical for several biological processes that control nuclear programs and Ca2+ handling.
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50
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Blaauw B. Platelet-Derived Growth Factor signaling and the role of cellular crosstalk in functional muscle growth. FEBS Lett 2019; 591:690-692. [PMID: 28297119 DOI: 10.1002/1873-3468.12602] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Affiliation(s)
- Bert Blaauw
- Department of Biomedical Sciences, University of Padova, Italy.,Venetian Institute of Molecular Medicine, Padova, Italy
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