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Oudhoff H, Hisler V, Baumgartner F, Rees L, Grepper D, Jaźwińska A. Skeletal muscle regeneration after extensive cryoinjury of caudal myomeres in adult zebrafish. NPJ Regen Med 2024; 9:8. [PMID: 38378693 PMCID: PMC10879182 DOI: 10.1038/s41536-024-00351-5] [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: 05/25/2023] [Accepted: 01/24/2024] [Indexed: 02/22/2024] Open
Abstract
Skeletal muscles can regenerate after minor injuries, but severe structural damage often leads to fibrosis in mammals. Whether adult zebrafish possess the capacity to reproduce profoundly destroyed musculature remains unknown. Here, a new cryoinjury model revealed that several myomeres efficiently regenerated within one month after wounding the zebrafish caudal peduncle. Wound clearance involved accumulation of the selective autophagy receptor p62, an immune response and Collagen XII deposition. New muscle formation was associated with proliferation of Pax7 expressing muscle stem cells, which gave rise to MyoD1 positive myogenic precursors, followed by myofiber differentiation. Monitoring of slow and fast muscles revealed their coordinated replacement in the superficial and profound compartments of the myomere. However, the final boundary between the muscular components was imperfectly recapitulated, allowing myofibers of different identities to intermingle. The replacement of connective with sarcomeric tissues required TOR signaling, as rapamycin treatment impaired new muscle formation, leading to persistent fibrosis. The model of zebrafish myomere restoration may provide new medical perspectives for treatment of traumatic injuries.
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Affiliation(s)
- Hendrik Oudhoff
- Department of Biology, University of Fribourg, Chemin du Musée 10, 1700, Fribourg, Switzerland
| | - Vincent Hisler
- Department of Biology, University of Fribourg, Chemin du Musée 10, 1700, Fribourg, Switzerland
| | - Florian Baumgartner
- Department of Biology, University of Fribourg, Chemin du Musée 10, 1700, Fribourg, Switzerland
| | - Lana Rees
- Department of Biology, University of Fribourg, Chemin du Musée 10, 1700, Fribourg, Switzerland
| | - Dogan Grepper
- Department of Biology, University of Fribourg, Chemin du Musée 10, 1700, Fribourg, Switzerland
| | - Anna Jaźwińska
- Department of Biology, University of Fribourg, Chemin du Musée 10, 1700, Fribourg, Switzerland.
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Han X, Goh KY, Lee WX, Choy SM, Tang HW. The Importance of mTORC1-Autophagy Axis for Skeletal Muscle Diseases. Int J Mol Sci 2022; 24:297. [PMID: 36613741 PMCID: PMC9820406 DOI: 10.3390/ijms24010297] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2022] [Revised: 12/15/2022] [Accepted: 12/20/2022] [Indexed: 12/28/2022] Open
Abstract
The mechanistic target of rapamycin (mTOR) complex 1, mTORC1, integrates nutrient and growth factor signals with cellular responses and plays critical roles in regulating cell growth, proliferation, and lifespan. mTORC1 signaling has been reported as a central regulator of autophagy by modulating almost all aspects of the autophagic process, including initiation, expansion, and termination. An increasing number of studies suggest that mTORC1 and autophagy are critical for the physiological function of skeletal muscle and are involved in diverse muscle diseases. Here, we review recent insights into the essential roles of mTORC1 and autophagy in skeletal muscles and their implications in human muscle diseases. Multiple inhibitors targeting mTORC1 or autophagy have already been clinically approved, while others are under development. These chemical modulators that target the mTORC1/autophagy pathways represent promising potentials to cure muscle diseases.
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Affiliation(s)
- Xujun Han
- Program in Cancer and Stem Cell Biology, Duke-NUS Medical School, 8 College Road, Singapore 169857, Singapore
| | - Kah Yong Goh
- Program in Cancer and Stem Cell Biology, Duke-NUS Medical School, 8 College Road, Singapore 169857, Singapore
| | - Wen Xing Lee
- Program in Cancer and Stem Cell Biology, Duke-NUS Medical School, 8 College Road, Singapore 169857, Singapore
| | - Sze Mun Choy
- Program in Cancer and Stem Cell Biology, Duke-NUS Medical School, 8 College Road, Singapore 169857, Singapore
| | - Hong-Wen Tang
- Program in Cancer and Stem Cell Biology, Duke-NUS Medical School, 8 College Road, Singapore 169857, Singapore
- Division of Cellular & Molecular Research, Humphrey Oei Institute of Cancer Research, National Cancer Centre Singapore, Singapore 169610, Singapore
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3
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Banik M, Adhya S. OXPHOS deficiency induces mitochondrial DNA synthesis through non-canonical AMPK-dependent mRNA compartmentalization. J Biosci 2022. [DOI: 10.1007/s12038-022-00303-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Neuregulin-1/ErbB4 upregulates acetylcholine receptors via Akt/mTOR/p70S6K: a study in a rat model of obstetric brachial plexus palsy and in vitro. Acta Biochim Biophys Sin (Shanghai) 2022; 54:1648-1657. [PMID: 36331297 PMCID: PMC9828288 DOI: 10.3724/abbs.2022158] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
In obstetric brachial plexus palsy (OBPP), the operative time window for nerve reconstruction of the intrinsic muscles of the hand (IMH) is much shorter than that of biceps. The reason is that the atrophy of IMH becomes irreversible more quickly than that of biceps. A previous study confirmed that the motor endplates of denervated intrinsic muscles of the forepaw (IMF) were destabilized, while those of denervated biceps remained intact. However, the specific molecular mechanism of regulating the self-repair of motor endplates is still unknown. In this study, we use a rat model of OBPP with right C5-C6 rupture plus C7-C8-T1 avulsion and left side as a control. Bilateral IMF and biceps are harvested at 5 weeks postinjury to assess relative protein and mRNA expression. We also use L6 skeletal myoblasts to verify the effects of signaling pathways regulating acetylcholine receptor (AChR) protein synthesis in vitro. The results show that in the OBPP rat model, the protein and mRNA expression levels of NRG-1/ErbB4 and phosphorylation of Akt/mTOR/p70S6K are lower in denervated IMF than in denervated biceps. In L6 myoblasts stimulated with NRG-1, overexpression and knockdown of ErbB4 lead to upregulation and downregulation of AChR subunit protein synthesis and Akt/mTOR/p70S6K phosphorylation, respectively. Inhibition of mTOR abolishes protein synthesis of AChR subunits elevated by NRG-1/ErbB4. Our findings suggest that in the OBPP rat model, lower expression of AChR subunits in the motor endplates of denervated IMF is associated with downregulation of NRG-1/ErbB4 and phosphorylation of Akt/mTOR/p70S6K. NRG-1/ErbB4 can promote protein synthesis of the AChR subunits in L6 myoblasts via phosphorylation of Akt/mTOR/p70S6K.
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mTORC1 Mediates the Processes of Lysine Regulating Satellite Cells Proliferation, Apoptosis, and Autophagy. Metabolites 2022; 12:metabo12090788. [PMID: 36144192 PMCID: PMC9505949 DOI: 10.3390/metabo12090788] [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: 08/07/2022] [Revised: 08/20/2022] [Accepted: 08/24/2022] [Indexed: 11/16/2022] Open
Abstract
Lysine (Lys) is essential for skeletal muscle growth and protein synthesis in mammals. However, the regulatory network underlying Lys-regulated skeletal muscle development is unknown. To determine whether any cross-talk occurs among mammalian targets of rapamycin complex 1 (mTORC1) and Lys in the regulation of muscle satellite cells (SCs) proliferation, we applied the treatment rapamycin (a mTORC1 inhibitor) and MHY1485 (a mTORC1 activator) on Lys-added or -deficient SCs. The results show Lys deprivation significantly decreases SCs viability, protein synthesis, and cell cycling, increases autophagy and apoptosis, and inhibits the mTORC1 signaling pathway. Restoration of Lys content significantly attenuates this effect. mTORC1 signaling pathway activation during Lys deprivation or mTORC1 signaling pathway inhibition during Lys addition attenuates the effect of Lys deprivation or addition on SCs viability, protein synthesis, cell cycling, autophagy, and apoptosis. In conclusion, Lys could improve SCs proliferation, and inhibit SCs apoptosis and autophagy, via the mTORC1 signaling pathway.
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Chen S, Lu XT, He TT, Yishake D, Tan XY, Hou MJ, Luo Y, Long JA, Tang ZH, Zhong RH, Fang AP, Zhu HL. Betaine Delayed Muscle Loss by Attenuating Samtor Complex Inhibition for mTORC1 Signaling Via Increasing SAM Level. Mol Nutr Food Res 2021; 65:e2100157. [PMID: 34061446 DOI: 10.1002/mnfr.202100157] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2021] [Revised: 04/29/2021] [Indexed: 01/26/2023]
Abstract
SCOPE The muscle loss during aging results from the blunt of protein synthesis and poses threat to the elderly health. This study aims to investigate whether betaine affects muscle loss by improving protein synthesis. METHODS AND RESULTS Male C57BL/6J mice are raised from age 12 or 15 months. Mice are fed with AIN-93M diet without or with 2% w/v betaine in distilled water as control group or betaine intervention group (Bet), respectively. Betaine supplementation to mice demonstrates better body composition, grip strength, and motor function. Muscle morphology upregulates expression of myogenic regulate factors, and elevates myosin heavy chain and also improves in Bet group. Betaine promotes muscle protein synthesis via tethering mammalian target of rapamycin complex1 protein kinase (mTORC1) on the lysosomal membrane thereby activating mTORC1 signaling. All these effects aforementioned are time-dependent (p < 0.05). Ultrahigh-performance liquid chromatography results show that betaine increases S-adenosyl-l-methionine (SAM) via methionine cycle. SAM sensor-Samtor-overexpression in C2C12 cells could displace mTORC1 from lysosome thereby inhibiting the mTORC1 signaling. Addition of betaine attenuates this inhibition by increasing SAM level and then disrupting interaction of Samtor complex. CONCLUSIONS These observations indicate that betaine could promisingly promote protein synthesis to delay age-related muscle loss.
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Affiliation(s)
- Si Chen
- Department of Nutrition, School of Public Health, Sun Yat-sen University, Guangzhou, 510080, China
- Guangdong Provincial Key Laboratory of Food, Nutrition and Health, Guangzhou, 510080, China
| | - Xiao-Ting Lu
- Department of Nutrition, School of Public Health, Sun Yat-sen University, Guangzhou, 510080, China
- Guangdong Provincial Key Laboratory of Food, Nutrition and Health, Guangzhou, 510080, China
| | - Tong-Tong He
- Department of Nutrition, School of Public Health, Sun Yat-sen University, Guangzhou, 510080, China
- Guangdong Provincial Key Laboratory of Food, Nutrition and Health, Guangzhou, 510080, China
| | - Dinuerguli Yishake
- Department of Nutrition, School of Public Health, Sun Yat-sen University, Guangzhou, 510080, China
- Guangdong Provincial Key Laboratory of Food, Nutrition and Health, Guangzhou, 510080, China
| | - Xu-Yin Tan
- Department of Nutrition, School of Public Health, Sun Yat-sen University, Guangzhou, 510080, China
- Guangdong Provincial Key Laboratory of Food, Nutrition and Health, Guangzhou, 510080, China
| | - Meng-Jun Hou
- Department of Nutrition, School of Public Health, Sun Yat-sen University, Guangzhou, 510080, China
- Guangdong Provincial Key Laboratory of Food, Nutrition and Health, Guangzhou, 510080, China
| | - Yun Luo
- Department of Nutrition, School of Public Health, Sun Yat-sen University, Guangzhou, 510080, China
- Guangdong Provincial Key Laboratory of Food, Nutrition and Health, Guangzhou, 510080, China
| | - Jing-An Long
- Department of Nutrition, School of Public Health, Sun Yat-sen University, Guangzhou, 510080, China
- Guangdong Provincial Key Laboratory of Food, Nutrition and Health, Guangzhou, 510080, China
| | - Zhi-Hong Tang
- Department of Nutrition, School of Public Health, Sun Yat-sen University, Guangzhou, 510080, China
- Guangdong Provincial Key Laboratory of Food, Nutrition and Health, Guangzhou, 510080, China
| | - Rong-Huan Zhong
- Department of Nutrition, School of Public Health, Sun Yat-sen University, Guangzhou, 510080, China
- Guangdong Provincial Key Laboratory of Food, Nutrition and Health, Guangzhou, 510080, China
| | - Ai-Ping Fang
- Department of Nutrition, School of Public Health, Sun Yat-sen University, Guangzhou, 510080, China
- Guangdong Provincial Key Laboratory of Food, Nutrition and Health, Guangzhou, 510080, China
| | - Hui-Lian Zhu
- Department of Nutrition, School of Public Health, Sun Yat-sen University, Guangzhou, 510080, China
- Guangdong Provincial Key Laboratory of Food, Nutrition and Health, Guangzhou, 510080, China
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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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8
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mTORC1 Mediates Lysine-Induced Satellite Cell Activation to Promote Skeletal Muscle Growth. Cells 2019; 8:cells8121549. [PMID: 31801253 PMCID: PMC6953079 DOI: 10.3390/cells8121549] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Revised: 11/23/2019] [Accepted: 11/25/2019] [Indexed: 12/19/2022] Open
Abstract
As the first limiting amino acid, lysine (Lys) has been thought to promote muscle fiber hypertrophy by increasing protein synthesis. However, the functions of Lys seem far more complex than that. Despite the fact that satellite cells (SCs) play an important role in skeletal muscle growth, the communication between Lys and SCs remains unclear. In this study, we investigated whether SCs participate directly in Lys-induced skeletal muscle growth and whether the mammalian target of rapamycin complex 1 (mTORC1) pathway was activated both in vivo and in vitro to mediate SC functions in response to Lys supplementation. Subsequently, the skeletal muscle growth of piglets was controlled by dietary Lys supplementation. Isobaric tag for relative and absolute quantitation (iTRAQ) analysis showed activated SCs were required for longissimus dorsi muscle growth, and this effect was accompanied by mTORC1 pathway upregulation. Furthermore, SC proliferation was governed by medium Lys concentrations, and the mTORC1 pathway was significantly enhanced in vitro. After verifying that rapamycin inhibits the mTORC1 pathway and suppresses SC proliferation, we conclude that Lys is not only a molecular building block for protein synthesis but also a signal that activates SCs to manipulate muscle growth via the mTORC1 pathway.
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9
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Wei X, Luo L, Chen J. Roles of mTOR Signaling in Tissue Regeneration. Cells 2019; 8:cells8091075. [PMID: 31547370 PMCID: PMC6769890 DOI: 10.3390/cells8091075] [Citation(s) in RCA: 75] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2019] [Revised: 09/06/2019] [Accepted: 09/07/2019] [Indexed: 12/11/2022] Open
Abstract
The mammalian target of rapamycin (mTOR), is a serine/threonine protein kinase and belongs to the phosphatidylinositol 3-kinase (PI3K)-related kinase (PIKK) family. mTOR interacts with other subunits to form two distinct complexes, mTORC1 and mTORC2. mTORC1 coordinates cell growth and metabolism in response to environmental input, including growth factors, amino acid, energy and stress. mTORC2 mainly controls cell survival and migration through phosphorylating glucocorticoid-regulated kinase (SGK), protein kinase B (Akt), and protein kinase C (PKC) kinase families. The dysregulation of mTOR is involved in human diseases including cancer, cardiovascular diseases, neurodegenerative diseases, and epilepsy. Tissue damage caused by trauma, diseases or aging disrupt the tissue functions. Tissue regeneration after injuries is of significance for recovering the tissue homeostasis and functions. Mammals have very limited regenerative capacity in multiple tissues and organs, such as the heart and central nervous system (CNS). Thereby, understanding the mechanisms underlying tissue regeneration is crucial for tissue repair and regenerative medicine. mTOR is activated in multiple tissue injuries. In this review, we summarize the roles of mTOR signaling in tissue regeneration such as neurons, muscles, the liver and the intestine.
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Affiliation(s)
- Xiangyong Wei
- Laboratory of Molecular Developmental Biology, School of Life Sciences, Southwest University, Beibei, Chongqing 400715, China.
| | - Lingfei Luo
- Laboratory of Molecular Developmental Biology, School of Life Sciences, Southwest University, Beibei, Chongqing 400715, China.
| | - Jinzi Chen
- Laboratory of Molecular Developmental Biology, School of Life Sciences, Southwest University, Beibei, Chongqing 400715, China.
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Cheikhi A, Wallace C, St Croix C, Cohen C, Tang WY, Wipf P, Benos PV, Ambrosio F, Barchowsky A. Mitochondria are a substrate of cellular memory. Free Radic Biol Med 2019; 130:528-541. [PMID: 30472365 DOI: 10.1016/j.freeradbiomed.2018.11.028] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/17/2018] [Revised: 11/19/2018] [Accepted: 11/21/2018] [Indexed: 12/26/2022]
Abstract
Cellular memory underlies cellular identity, and thus constitutes a unifying mechanism of genetic disposition, environmental influences, and cellular adaptation. Here, we demonstrate that enduring physicochemical changes of mitochondrial networks invoked by transient stress, a phenomenon we term 'mitoengrams', underlie the transgenerational persistence of epigenetically scripted cellular behavior. Using C2C12 myogenic stem-like cells, we show that stress memory elicited by transient, low-level arsenite exposure is stored within a self-renewing subpopulation of progeny cells in a mitochondrial-dependent fashion. Importantly, we demonstrate that erasure of mitoengrams by administration of mitochondria-targeted electron scavenger was sufficient to reset key epigenetic marks of cellular memory and redirect the identity of the mitoengram-harboring progeny cells to a non-stress-like state. Together, our findings indicate that mnemonic information emanating from mitochondria support the balance between the persistence and transience of cellular memory.
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Affiliation(s)
- Amin Cheikhi
- Division of Geriatric Medicine, Department of Medicine, University of Pittsburgh, Pittsburgh, PA 15261, USA; Department of Environmental and Occupational Health, University of Pittsburgh, Pittsburgh, PA 15261, USA.
| | - Callen Wallace
- Center for Biological Imaging, University of Pittsburgh, Pittsburgh, PA 15261, USA.
| | - Claudette St Croix
- Center for Biological Imaging, University of Pittsburgh, Pittsburgh, PA 15261, USA; Department of Cell Biology, University of Pittsburgh, Pittsburgh, PA 15261, USA.
| | - Charles Cohen
- Department of Environmental and Occupational Health, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Wan-Yee Tang
- Department of Environmental Health and Engineering, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA.
| | - Peter Wipf
- Department of Chemistry, University of Pittsburgh, Pittsburgh, PA 15260, USA.
| | - Panagiotis V Benos
- Department of Computational and Systems Biology, University of Pittsburgh, Pittsburgh, PA 15261, USA.
| | - Fabrisia Ambrosio
- Department of Environmental and Occupational Health, University of Pittsburgh, Pittsburgh, PA 15261, USA; Department of Physical Medicine and Rehabilitation, University of Pittsburgh, Pittsburgh, PA, USA; McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA 15219, USA; Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA 15261, USA.
| | - Aaron Barchowsky
- Department of Environmental and Occupational Health, University of Pittsburgh, Pittsburgh, PA 15261, USA; Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA 15261, USA.
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11
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Reidy PT, Fry CS, Dickinson JM, Drummond MJ, Rasmussen BB. Postexercise essential amino acid supplementation amplifies skeletal muscle satellite cell proliferation in older men 24 hours postexercise. Physiol Rep 2018; 5:5/11/e13269. [PMID: 28596299 PMCID: PMC5471431 DOI: 10.14814/phy2.13269] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2017] [Revised: 03/31/2017] [Accepted: 04/06/2017] [Indexed: 12/29/2022] Open
Abstract
Aged skeletal muscle has an attenuated and delayed ability to proliferate satellite cells in response to resistance exercise. The mechanistic target of rapamycin complex 1 (mTORC1) signaling pathway is a focal point for cell growth, however, the effect of postexercise mTORC1 activation on human skeletal muscle satellite cell (SC) proliferation is unknown. To test the proliferative capacity of skeletal muscle SC in aging muscle to a potent mTORC1 activator (i.e., EAA; essential amino acids) we recruited older (~72y) men to conduct leg resistance exercise (8setsx10reps) without (−EAA; n = 8) and with (+EAA: n = 11) ingestion of 10 g of EAA 1 h postexercise. Muscle biopsies were taken before exercise (Pre) and 24 h postexercise (Post) for assessment of expression and fiber type‐specific Pax7+SC, Ki67+Pax7+SC and MyoD+SC. −EAA did not show an increase in Pax7+ satellite cells at Post(P > 0.82). Although statistical significance for an increase in Pax7 + SC at 24 h post‐RE was not observed in +EAA versus −EAA, we observed trends for a treatment difference (P < 0.1). When examining the change from Pre to Post trends were demonstrated (#/myofiber: P = 0.076; and %/myonuclei: P = 0.065) for a greater increase in +EAA versus −EAA. Notably, we found an increase SC proliferation in +EAA, but not −EAA with increase in Ki67+SC and MyoD+ cells (P < 0.05). Ki67+SC also exhibited a significant group difference Post (P < 0.010). Pax7+SC in fast twitch myofibers did not change and were not different between groups (P > 0.10). CDK2, MEF2C, RB1 mRNA only increased in +EAA (P < 0.05). Acute muscle satellite cell proliferative capacity may be partially rescued with postexercise EAA ingestion in older men.
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Affiliation(s)
- Paul T Reidy
- Center for Recovery, Physical Activity and Nutrition, University of Texas Medical Branch, Galveston, Texas.,Department of Nutrition and Metabolism, University of Texas Medical Branch, Galveston, Texas
| | - Christopher S Fry
- Department of Nutrition and Metabolism, University of Texas Medical Branch, Galveston, Texas
| | - Jared M Dickinson
- Center for Recovery, Physical Activity and Nutrition, University of Texas Medical Branch, Galveston, Texas.,Department of Nutrition and Metabolism, University of Texas Medical Branch, Galveston, Texas
| | - Micah J Drummond
- Department of Nutrition and Metabolism, University of Texas Medical Branch, Galveston, Texas
| | - Blake B Rasmussen
- Center for Recovery, Physical Activity and Nutrition, University of Texas Medical Branch, Galveston, Texas .,Department of Nutrition and Metabolism, University of Texas Medical Branch, Galveston, Texas
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12
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Shamim B, Hawley JA, Camera DM. Protein Availability and Satellite Cell Dynamics in Skeletal Muscle. Sports Med 2018; 48:1329-1343. [DOI: 10.1007/s40279-018-0883-7] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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13
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Ghosh U, Adhya S. Non-equivalent Roles of AGO1 and AGO2 in mRNA Turnover and Translation of Cyclin D1 mRNA. J Biol Chem 2016; 291:7119-27. [PMID: 26846850 DOI: 10.1074/jbc.m115.696377] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2015] [Indexed: 11/06/2022] Open
Abstract
Mammalian Argonaute proteins (AGO1-4), in combination with microRNAs (miRs), bind to target mRNAs to initiate degradation and/or translation repression, but the relationships between these two effects is unclear. Although the AGO isoforms ofDrosophilaand plants perform different functions, mammalian AGO isoforms are considered to be functionally degenerate in terms of miR loading and downstream silencing effects. However, we found that, in quiescent (G0) rat myoblasts transiting to the G1 phase, cyclin D1 (Ccnd1) mRNA was associated with two functionally distinct AGO-miR complexes. While AGO1-miR-1 down-regulated the mRNA level, AGO2-let-7 delayed the timing of translation. Knockdown (KD) of AGO2, or antisense-mediated depletion of Let-7, caused Ccnd1 translation to occur earlier, but had no significant effect on mRNA abundance. Conversely, down-regulation of either AGO1 or miR-1, resulted in elevated Ccnd1 mRNA levels at early times, but failed to affect the timing of translation. These results show that the two miR-mediated silencing effects, viz. mRNA decay and translation repression, are independent processes induced by individual AGO isoforms in association with specific miRs.
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Affiliation(s)
- Utpalendu Ghosh
- From the Genetic Engineering Laboratory, CSIR-Indian Institute of Chemical Biology, 4 Raja S. C. Mullick Road, Calcutta 700032, India
| | - Samit Adhya
- From the Genetic Engineering Laboratory, CSIR-Indian Institute of Chemical Biology, 4 Raja S. C. Mullick Road, Calcutta 700032, India
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14
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Muscle-specific microRNAs in skeletal muscle development. Dev Biol 2016; 410:1-13. [DOI: 10.1016/j.ydbio.2015.12.013] [Citation(s) in RCA: 281] [Impact Index Per Article: 35.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Revised: 12/15/2015] [Accepted: 12/16/2015] [Indexed: 01/19/2023]
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15
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Azizi S, Nematollahi MA, Mojazi Amiri B, Vélez EJ, Lutfi E, Navarro I, Capilla E, Gutiérrez J. Lysine and Leucine Deficiencies Affect Myocytes Development and IGF Signaling in Gilthead Sea Bream (Sparus aurata). PLoS One 2016; 11:e0147618. [PMID: 26808650 PMCID: PMC4725776 DOI: 10.1371/journal.pone.0147618] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Accepted: 01/06/2016] [Indexed: 11/18/2022] Open
Abstract
Optimizing aquaculture production requires better knowledge of growth regulation and improvement in diet formulation. A great effort has been made to replace fish meal for plant protein sources in aquafeeds, making necessary the supplementation of such diets with crystalline amino acids (AA) to cover the nutritional requirements of each species. Lysine and Leucine are limiting essential AA in fish, and it has been demonstrated that supplementation with them improves growth in different species. However, the specific effects of AA deficiencies in myogenesis are completely unknown and have only been studied at the level of hepatic metabolism. It is well-known that the TOR pathway integrates the nutritional and hormonal signals to regulate protein synthesis and cell proliferation, to finally control muscle growth, a process also coordinated by the expression of myogenic regulatory factors (MRFs). This study aimed to provide new information on the impact of Lysine and Leucine deficiencies in gilthead sea bream cultured myocytes examining their development and the response of insulin-like growth factors (IGFs), MRFs, as well as key molecules involved in muscle growth regulation like TOR. Leucine deficiency did not cause significant differences in most of the molecules analyzed, whereas Lysine deficiency appeared crucial in IGFs regulation, decreasing significantly IGF-I, IGF-II and IGF-IRb mRNA levels. This treatment also down-regulated the gene expression of different MRFs, including Myf5, Myogenin and MyoD2. These changes were also corroborated by a significant decrease in proliferation and differentiation markers in the Lysine-deficient treatment. Moreover, both Lysine and Leucine limitation induced a significant down-regulation in FOXO3 gene expression, which deserves further investigation. We believe that these results will be relevant for the production of a species as appreciated for human consumption as it is gilthead sea bream and demonstrates the importance of an adequate level of Lysine in fishmeal diet formulation for optimum growth.
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Affiliation(s)
- Sheida Azizi
- Department of Fisheries Sciences, Faculty of Natural Resources, University of Tehran, Karaj, Iran
- Departament de Fisiologia i Immunologia, Facultat de Biologia, Universitat de Barcelona, 08028, Barcelona, Spain
| | - Mohammad Ali Nematollahi
- Department of Fisheries Sciences, Faculty of Natural Resources, University of Tehran, Karaj, Iran
- * E-mail: (MAN); (JG)
| | - Bagher Mojazi Amiri
- Department of Fisheries Sciences, Faculty of Natural Resources, University of Tehran, Karaj, Iran
| | - Emilio J. Vélez
- Departament de Fisiologia i Immunologia, Facultat de Biologia, Universitat de Barcelona, 08028, Barcelona, Spain
| | - Esmail Lutfi
- Departament de Fisiologia i Immunologia, Facultat de Biologia, Universitat de Barcelona, 08028, Barcelona, Spain
| | - Isabel Navarro
- Departament de Fisiologia i Immunologia, Facultat de Biologia, Universitat de Barcelona, 08028, Barcelona, Spain
| | - Encarnación Capilla
- Departament de Fisiologia i Immunologia, Facultat de Biologia, Universitat de Barcelona, 08028, Barcelona, Spain
| | - Joaquim Gutiérrez
- Departament de Fisiologia i Immunologia, Facultat de Biologia, Universitat de Barcelona, 08028, Barcelona, Spain
- * E-mail: (MAN); (JG)
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Zhang Z, Zhang G, Kong C, Gong D. PP242 suppresses bladder cancer cell proliferation and migration through deactivating the mammalian target of rapamycin complex 2/AKT1 signaling pathway. Mol Med Rep 2015; 13:333-8. [PMID: 26548560 DOI: 10.3892/mmr.2015.4528] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2015] [Accepted: 10/06/2015] [Indexed: 11/06/2022] Open
Abstract
While most cancer types are resistant to mammalian target of rapamycin complex 1 (mTORC1) inhibitor rapamycin, recent studies have identified mTORC2 as an important prospective therapeutic target for cancer. The present study assessed the effects of mTORC2 inhibitor PP242 on the proliferation and migration of bladder cancer cells by using Cell Counting Kit‑8, 5‑ethynyl‑2'‑deoxyuridine incorporation, wound healing and Transwell assays. Furthermore, the phosphorylation status of downstream signaling proteins of mTORC1 and mTORC2 was assessed using western blot analysis. The results demonstrated that PP242 concentration‑dependently inhibited the proliferation of bladder cancer cells. Simultaneously, the migration ability of bladder cancer cells was suppressed by PP242. In addition, PP242 markedly restrained the phosphorylation of AKT1 and mTORC2, while the phosphorylation status of S6K1 and mTORC1 was not affected. These results suggested that PP242 exerts potent inhibitory effects on bladder cancer cells by modulating the activity of the mTORC2/AKT1 pathway.
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Affiliation(s)
- Zhe Zhang
- Department of Urology, The First Hospital of China Medical University, Shenyang, Liaoning 110001, P.R. China
| | - Guojun Zhang
- Department of Hematology, Shengjing Hospital of China Medical University, Shenyang, Liaoning 110022, P.R. China
| | - Chuize Kong
- Department of Urology, The First Hospital of China Medical University, Shenyang, Liaoning 110001, P.R. China
| | - Daxin Gong
- Department of Urology, The First Hospital of China Medical University, Shenyang, Liaoning 110001, P.R. China
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17
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Doles JD, Olwin BB. Muscle stem cells on the edge. Curr Opin Genet Dev 2015; 34:24-8. [DOI: 10.1016/j.gde.2015.06.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2015] [Revised: 06/04/2015] [Accepted: 06/16/2015] [Indexed: 10/23/2022]
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18
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Moresi V, Marroncelli N, Adamo S. New insights into the epigenetic control of satellite cells. World J Stem Cells 2015; 7:945-955. [PMID: 26240681 PMCID: PMC4515437 DOI: 10.4252/wjsc.v7.i6.945] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/26/2014] [Revised: 02/12/2015] [Accepted: 05/11/2015] [Indexed: 02/06/2023] Open
Abstract
Epigenetics finely tunes gene expression at a functional level without modifying the DNA sequence, thereby contributing to the complexity of genomic regulation. Satellite cells (SCs) are adult muscle stem cells that are important for skeletal post-natal muscle growth, homeostasis and repair. The understanding of the epigenome of SCs at different stages and of the multiple layers of the post-transcriptional regulation of gene expression is constantly expanding. Dynamic interactions between different epigenetic mechanisms regulate the appropriate timing of muscle-specific gene expression and influence the lineage fate of SCs. In this review, we report and discuss the recent literature about the epigenetic control of SCs during the myogenic process from activation to proliferation and from their commitment to a muscle cell fate to their differentiation and fusion to myotubes. We describe how the coordinated activities of the histone methyltransferase families Polycomb group (PcG), which represses the expression of developmentally regulated genes, and Trithorax group, which antagonizes the repressive activity of the PcG, regulate myogenesis by restricting gene expression in a time-dependent manner during each step of the process. We discuss how histone acetylation and deacetylation occurs in specific loci throughout SC differentiation to enable the time-dependent transcription of specific genes. Moreover, we describe the multiple roles of microRNA, an additional epigenetic mechanism, in regulating gene expression in SCs, by repressing or enhancing gene transcription or translation during each step of myogenesis. The importance of these epigenetic pathways in modulating SC activation and differentiation renders them as promising targets for disease interventions. Understanding the most recent findings regarding the epigenetic mechanisms that regulate SC behavior is useful from the perspective of pharmacological manipulation for improving muscle regeneration and for promoting muscle homeostasis under pathological conditions.
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Regulation of skeletal muscle development and homeostasis by gene imprinting, histone acetylation and microRNA. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2015; 1849:309-16. [DOI: 10.1016/j.bbagrm.2015.01.002] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2014] [Revised: 12/17/2014] [Accepted: 01/10/2015] [Indexed: 12/13/2022]
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Sohi G, Dilworth FJ. Noncoding RNAs as epigenetic mediators of skeletal muscle regeneration. FEBS J 2015; 282:1630-46. [PMID: 25483175 DOI: 10.1111/febs.13170] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2014] [Revised: 12/01/2014] [Accepted: 12/02/2014] [Indexed: 12/16/2022]
Abstract
Skeletal muscle regeneration is a well-characterized biological process in which resident adult stem cells must undertake a series of cell-fate decisions to ensure efficient repair of the damaged muscle fibers while also maintaining the stem cell niche. Satellite cells, the main stem cell contributing to the repaired muscle fiber, are maintained in a quiescent state in healthy muscle. Upon injury, the satellite cells become activated, and proliferate to expand the muscle progenitor cell population before returning to the quiescent state or differentiating to become myofibers. Importantly, the determination of cell fate is controlled at the epigenetic level in response to environmental cues. In this review, we discuss our current understanding of the role played by noncoding RNAs (both miRNAs and long-noncoding RNAs) in the epigenetic control of muscle regeneration.
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Affiliation(s)
- Gurjeev Sohi
- Sprott Center for Stem Cell Research, Regenerative Medicine Program, Ottawa Hospital Research Institute, Canada
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