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Nuccio A, Nogueira-Ferreira R, Moreira-Pais A, Attanzio A, Duarte JA, Luparello C, Ferreira R. The contribution of mitochondria to age-related skeletal muscle wasting: A sex-specific perspective. Life Sci 2024; 336:122324. [PMID: 38042281 DOI: 10.1016/j.lfs.2023.122324] [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: 09/09/2023] [Revised: 11/27/2023] [Accepted: 11/29/2023] [Indexed: 12/04/2023]
Abstract
As people age, their skeletal muscle (SkM) experiences a decline in mitochondrial functionality and density, which leads to decreased energy production and increased generation of reactive oxygen species. This cascade of events, in turn, might determine the loss of SkM mass, strength and quality. Even though the mitochondrial processes dysregulated by aging, such as oxidative phosphorylation, mitophagy, antioxidant defenses and mtDNA transcription, are the same in both sexes, mitochondria age differently in the SkM of men and women. Indeed, the onset and magnitude of the impairment of these processes seem to be influenced by sex-specific factors. Sexual hormones play a pivotal role in the regulation of SkM mass through both genomic and non-genomic mechanisms. However, the precise mechanisms by which these hormones regulate mitochondrial plasticity in SkM are not fully understood. Although the presence of estrogen receptors in mitochondria is recognized, it remains unclear whether androgen receptors affect mitochondrial function. This comprehensive review critically dissects the current knowledge on the interplay of sex in the aging of SkM, focusing on the role of sex hormones and the corresponding signaling pathways in shaping mitochondrial plasticity. Improved knowledge on the sex dimorphism of mitochondrial aging may lead to sex-tailored interventions that target mitochondrial health, which could be effective in slowing or preventing age-related muscle loss.
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Affiliation(s)
- Alessandro Nuccio
- LAQV/REQUIMTE, Department of Chemistry, University of Aveiro, 3810-193 Aveiro, Portugal; Department of Biological, Chemical and Pharmaceutical Sciences and Technologies (STEBICEF), University of Palermo, 90128 Palermo, Italy.
| | - Rita Nogueira-Ferreira
- Cardiovascular R&D Center - UnIC@RISE, Department of Surgery and Physiology, Faculty of Medicine of the University of Porto, 4200-319 Porto, Portugal.
| | - Alexandra Moreira-Pais
- LAQV/REQUIMTE, Department of Chemistry, University of Aveiro, 3810-193 Aveiro, Portugal; Research Center in Physical Activity, Health and Leisure (CIAFEL), Faculty of Sports, University of Porto (FADEUP), Laboratory for Integrative and Translational Research in Population Health (ITR), 4200-450 Porto, Portugal; Centre for Research and Technology of Agro Environmental and Biological Sciences (CITAB), Inov4Agro, University of Trás-os-Montes and Alto Douro (UTAD), Quinta de Prados, 5000-801 Vila Real, Portugal.
| | - Alessandro Attanzio
- Department of Biological, Chemical and Pharmaceutical Sciences and Technologies (STEBICEF), University of Palermo, 90128 Palermo, Italy.
| | - José Alberto Duarte
- Research Center in Physical Activity, Health and Leisure (CIAFEL), Faculty of Sports, University of Porto (FADEUP), Laboratory for Integrative and Translational Research in Population Health (ITR), 4200-450 Porto, Portugal; TOXRUN - Toxicology Research Unit, University Institute of Health Sciences, CESPU, CRL, 4585-116 Gandra, Portugal.
| | - Claudio Luparello
- Department of Biological, Chemical and Pharmaceutical Sciences and Technologies (STEBICEF), University of Palermo, 90128 Palermo, Italy.
| | - Rita Ferreira
- LAQV/REQUIMTE, Department of Chemistry, University of Aveiro, 3810-193 Aveiro, Portugal.
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Motsinger LA, Okamoto LL, Ineck NE, Udy BA, Erickson CL, Harraq Y, Reichhardt CC, Murdoch GK, Thornton KJ. Understanding the Effects of Trenbolone Acetate, Polyamine Precursors, and Polyamines on Proliferation, Protein Synthesis Rates, and the Abundance of Genes Involved in Myoblast Growth, Polyamine Biosynthesis, and Protein Synthesis in Murine Myoblasts. BIOLOGY 2023; 12:biology12030446. [PMID: 36979138 PMCID: PMC10045634 DOI: 10.3390/biology12030446] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2023] [Revised: 03/08/2023] [Accepted: 03/10/2023] [Indexed: 03/17/2023]
Abstract
Research suggests that androgens increase skeletal muscle growth by modulating polyamine biosynthesis. As such, the objective of this study was to investigate effects of anabolic hormones, polyamine precursors, and polyamines relative to proliferation, protein synthesis, and the abundance of mRNA involved in polyamine biosynthesis, proliferation, and protein synthesis in C2C12 and Sol8 cells. Cultures were treated with anabolic hormones (trenbolone acetate and/or estradiol), polyamine precursors (methionine or ornithine), or polyamines (putrescine, spermidine, or spermine). Messenger RNA was isolated 0.5 or 1, 12, or 24 h post-treatment. The cell type had no effect (p > 0.10) on proliferation, protein synthesis, or mRNA abundance at any time point. Each treatment increased (p < 0.01) proliferation, and anabolic hormones increased (p = 0.04) protein synthesis. Polyamines increased (p < 0.05) the abundance of mRNA involved in polyamine biosynthesis, proliferation, and protein synthesis. Treatment with polyamine precursors decreased (p < 0.05) the abundance of mRNA involved in proliferation and protein synthesis. Overall, C2C12 and Sol8 myoblasts do not differ (p > 0.10) in proliferation, protein synthesis, or mRNA abundance at the time points assessed. Furthermore, anabolic hormones, polyamines, and polyamine precursors increase proliferation and protein synthesis, and polyamines and their precursors alter the abundance of mRNA involved in growth.
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Affiliation(s)
- Laura A. Motsinger
- Department of Animal, Dairy and Veterinary Sciences, Utah State University, Logan, UT 84322, USA
| | - Lillian L. Okamoto
- Department of Animal, Dairy and Veterinary Sciences, Utah State University, Logan, UT 84322, USA
| | - Nikole E. Ineck
- Department of Animal, Dairy and Veterinary Sciences, Utah State University, Logan, UT 84322, USA
| | - Brynne A. Udy
- Department of Animal, Dairy and Veterinary Sciences, Utah State University, Logan, UT 84322, USA
| | - Christopher L. Erickson
- Department of Animal, Dairy and Veterinary Sciences, Utah State University, Logan, UT 84322, USA
| | - Youssef Harraq
- Department of Animal, Dairy and Veterinary Sciences, Utah State University, Logan, UT 84322, USA
| | - Caleb C. Reichhardt
- Department of Animal, Dairy and Veterinary Sciences, Utah State University, Logan, UT 84322, USA
| | - Gordon K. Murdoch
- Department of Animal Sciences, Washington State University, Pullman, WA 99163, USA
| | - Kara Jean Thornton
- Department of Animal, Dairy and Veterinary Sciences, Utah State University, Logan, UT 84322, USA
- Correspondence: ; Tel.: +435-797-7696; Fax: +435-797-2118
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Seo JY, Kim JH, Kong YY. Unraveling the Paradoxical Action of Androgens on Muscle Stem Cells. Mol Cells 2019; 42:97-103. [PMID: 30759971 PMCID: PMC6399011 DOI: 10.14348/molcells.2019.0004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2019] [Accepted: 01/07/2019] [Indexed: 12/25/2022] Open
Abstract
Androgens act in almost all tissues throughout the lifetime and have important roles in skeletal muscles. The levels of androgens increase during puberty and remain sustained at high levels in adulthood. Because androgens have an anabolic effect on skeletal muscles and muscle stem cells, these increased levels of androgens after puberty should lead to spontaneous muscle hypertrophy and hyperplasia in adulthood. However, the maintenance of muscle volume, myonuclei number per myofiber, and quiescent state of satellite cells in adulthood despite the high levels of androgens produces paradoxical outcomes. Our recent study revealed that the physiological increase of androgens at puberty initiates the transition of muscle stem cells from proliferation to quiescence by the androgen-Mindbomb1-Notch signaling axis. This newly discovered androgen action on skeletal muscles underscores the physiological importance of androgens on muscle homeostasis throughout life. This review will provide an overview of the new androgen action on skeletal muscles and discuss the paradoxical effects of androgens suggested in previous studies.
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Affiliation(s)
- Ji-Yun Seo
- School of Biological Sciences, Seoul National University, Seoul 08826,
Korea
| | - Ji-Hoon Kim
- School of Biological Sciences, Seoul National University, Seoul 08826,
Korea
| | - Young-Yun Kong
- School of Biological Sciences, Seoul National University, Seoul 08826,
Korea
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Muta Y, Tanaka T, Hamaguchi Y, Hamanoue N, Motonaga R, Tanabe M, Nomiyama T, Nawata H, Yanase T. Selective androgen receptor modulator, S42 has anabolic and anti-catabolic effects on cultured myotubes. Biochem Biophys Rep 2019; 17:177-181. [PMID: 30705972 PMCID: PMC6348734 DOI: 10.1016/j.bbrep.2019.01.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2018] [Revised: 11/30/2018] [Accepted: 01/08/2019] [Indexed: 12/14/2022] Open
Abstract
We previously identified a novel selective androgen receptor modulator, S42, that does not stimulate prostate growth but has a beneficial effect on lipid metabolism. S42 also increased muscle weight of the levator ani in orchiectomized Sprague–Dawley rats. These findings prompted us to investigate whether S42 has a direct effect on cultured C2C12 myotubes. S42 significantly lowered expression levels of the skeletal muscle ubiquitin ligase (muscle atrophy-related gene), atrogin1 and Muscle RING-Finger Protein 1(MuRF1) in C2C12 myotubes, as determined by real time PCR. Phosphorylation of p70 S6 kinase (p70S6K), an essential factor for promoting protein synthesis in skeletal muscle, was significantly increased by S42 to almost the same extent as by insulin, but this was significantly prevented by treatment with rapamycin, an inhibitor of mechanistic target of rapamycin complex 1 (mTORC1). However, phosphorylation of Akt, upstream regulator of mTORC1, was not changed by S42. S42 did not increase insulin-like growth factor 1 (Igf1) mRNA levels in C2C12 myotubes. These results suggest that S42 may have an anabolic effect through activation of mTORC1–p70S6K signaling, independent of IGF-1-Akt signaling and may exert an anti-catabolic effect through inhibition of the degradation pathway in cultured C2C12 myotubes. A SARM, S42 lowered expression levels of atrogin1 and MuRF1 mRNA in C2C12 myotubes. S42 increased phosphorylation of p70S6K through activation of mTORC1 in C2C12 myotubes. S42 may have anti-catabolic and anabolic effect in vitro.
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Affiliation(s)
- Yoshimi Muta
- Department of Endocrinology and Diabetes Mellitus, Faculty of Medicine, Fukuoka University, 7-45-1 Nanakuma, Jonan-ku, Fukuoka 814-0180, Japan
| | - Tomoko Tanaka
- Department of Endocrinology and Diabetes Mellitus, Faculty of Medicine, Fukuoka University, 7-45-1 Nanakuma, Jonan-ku, Fukuoka 814-0180, Japan.,The Department of Bioregulatory Science of Life-related Diseases of Fukuoka University, Fukuoka 814-0180, Japan
| | - Yuriko Hamaguchi
- Department of Endocrinology and Diabetes Mellitus, Faculty of Medicine, Fukuoka University, 7-45-1 Nanakuma, Jonan-ku, Fukuoka 814-0180, Japan
| | - Nobuya Hamanoue
- Department of Endocrinology and Diabetes Mellitus, Faculty of Medicine, Fukuoka University, 7-45-1 Nanakuma, Jonan-ku, Fukuoka 814-0180, Japan
| | - Ryoko Motonaga
- Department of Endocrinology and Diabetes Mellitus, Faculty of Medicine, Fukuoka University, 7-45-1 Nanakuma, Jonan-ku, Fukuoka 814-0180, Japan
| | - Makito Tanabe
- Department of Endocrinology and Diabetes Mellitus, Faculty of Medicine, Fukuoka University, 7-45-1 Nanakuma, Jonan-ku, Fukuoka 814-0180, Japan
| | - Takashi Nomiyama
- Department of Endocrinology and Diabetes Mellitus, Faculty of Medicine, Fukuoka University, 7-45-1 Nanakuma, Jonan-ku, Fukuoka 814-0180, Japan.,The Department of Bioregulatory Science of Life-related Diseases of Fukuoka University, Fukuoka 814-0180, Japan
| | - Hajime Nawata
- Muta Hospital, 3-9-1, Hoshikuma, Sawara-ku Fukuoka-shi, Fukuoka 814-0163, Japan
| | - Toshihiko Yanase
- Department of Endocrinology and Diabetes Mellitus, Faculty of Medicine, Fukuoka University, 7-45-1 Nanakuma, Jonan-ku, Fukuoka 814-0180, Japan.,The Department of Bioregulatory Science of Life-related Diseases of Fukuoka University, Fukuoka 814-0180, Japan
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Overexpression of miRNA-9 Generates Muscle Hypercontraction Through Translational Repression of Troponin-T in Drosophila melanogaster Indirect Flight Muscles. G3-GENES GENOMES GENETICS 2017; 7:3521-3531. [PMID: 28866639 PMCID: PMC5633399 DOI: 10.1534/g3.117.300232] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
MicroRNAs (miRNAs) are small noncoding endogenous RNAs, typically 21-23 nucleotides long, that regulate gene expression, usually post-transcriptionally, by binding to the 3'-UTR of target mRNA, thus blocking translation. The expression of several miRNAs is significantly altered during cardiac hypertrophy, myocardial ischemia, fibrosis, heart failure, and other cardiac myopathies. Recent studies have implicated miRNA-9 (miR-9) in myocardial hypertrophy. However, a detailed mechanism remains obscure. In this study, we have addressed the roles of miR-9 in muscle development and function using a genetically tractable model system, the indirect flight muscles (IFMs) of Drosophila melanogaster Bioinformatics analysis identified 135 potential miR-9a targets, of which 27 genes were associated with Drosophila muscle development. Troponin-T (TnT) was identified as major structural gene target of miR-9a. We show that flies overexpressing miR-9a in the IFMs have abnormal wing position and are flightless. These flies also exhibit a loss of muscle integrity and sarcomeric organization causing an abnormal muscle condition known as "hypercontraction." Additionally, miR-9a overexpression resulted in the reduction of TnT protein levels while transcript levels were unaffected. Furthermore, muscle abnormalities associated with miR-9a overexpression were completely rescued by overexpression of TnT transgenes which lacked the miR-9a binding site. These findings indicate that miR-9a interacts with the 3'-UTR of the TnT mRNA and downregulates the TnT protein levels by translational repression. The reduction in TnT levels leads to a cooperative downregulation of other thin filament structural proteins. Our findings have implications for understanding the cellular pathophysiology of cardiomyopathies associated with miR-9 overexpression.
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Combined Effects of Androgen and Growth Hormone on Osteoblast Marker Expression in Mouse C2C12 and MC3T3-E1 Cells Induced by Bone Morphogenetic Protein. J Clin Med 2017; 6:jcm6010006. [PMID: 28067796 PMCID: PMC5294959 DOI: 10.3390/jcm6010006] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2016] [Revised: 12/07/2016] [Accepted: 01/03/2017] [Indexed: 11/17/2022] Open
Abstract
Osteoblasts undergo differentiation in response to various factors, including growth factors and steroids. Bone mass is diminished in androgen- and/or growth hormone (GH)-deficient patients. However the functional relationship between androgen and GH, and their combined effects on bone metabolism, remains unclear. Here we investigated the mutual effects of androgen and GH on osteoblastic marker expression using mouse myoblastic C2C12 and osteoblast-like MC3T3-E1 cells. Combined treatment with dihydrotestosterone (DHT) and GH enhanced BMP-2-induced expression of Runx2, ALP, and osteocalcin mRNA, compared with the individual treatments in C2C12 cells. Co-treatment with DHT and GH activated Smad1/5/8 phosphorylation, Id-1 transcription, and ALP activity induced by BMP-2 in C2C12 cells but not in MC3T3-E1 cells. The insulin-like growth factor (IGF-I) mRNA level was amplified by GH and BMP-2 treatment and was restored by co-treatment with DHT in C2C12 cells. The mRNA level of the IGF-I receptor was not significantly altered by GH or DHT, while it was increased by IGF-I. In addition, IGF-I treatment increased collagen-1 mRNA expression, whereas blockage of endogenous IGF-I activity using an anti-IGF-I antibody failed to suppress the effect of GH and DHT on BMP-2-induced Runx2 expression in C2C12 cells, suggesting that endogenous IGF-I was not substantially involved in the underlying GH actions. On the other hand, androgen receptor and GH receptor mRNA expression was suppressed by BMP-2 in both cell lines, implying the existence of a feedback action. Collectively the results showed that the combined effects of androgen and GH facilitated BMP-2-induced osteoblast differentiation at an early stage by upregulating BMP receptor signaling.
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Kim YJ, Tamadon A, Park HT, Kim H, Ku SY. The role of sex steroid hormones in the pathophysiology and treatment of sarcopenia. Osteoporos Sarcopenia 2016; 2:140-155. [PMID: 30775480 PMCID: PMC6372754 DOI: 10.1016/j.afos.2016.06.002] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/18/2016] [Revised: 06/09/2016] [Accepted: 06/17/2016] [Indexed: 12/18/2022] Open
Abstract
Sex steroids influence the maintenance and growth of muscles. Decline in androgens, estrogens and progesterone by aging leads to the loss of muscular function and mass, sarcopenia. These steroid hormones can interact with different signaling pathways through their receptors. To date, sex steroid hormone receptors and their exact roles are not completely defined in skeletal and smooth muscles. Although numerous studies focused on the effects of sex steroid hormones on different types of cells, still many unexplained molecular mechanisms in both skeletal and smooth muscle cells remain to be investigated. In this paper, many different molecular mechanisms that are activated or inhibited by sex steroids and those that influence the growth, proliferation, and differentiation of skeletal and smooth muscle cells are reviewed. Also, the similarities of cellular and molecular pathways of androgens, estrogens and progesterone in both skeletal and smooth muscle cells are highlighted. The reviewed signaling pathways and participating molecules can be targeted in the future development of novel therapeutics.
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Affiliation(s)
- Yong Jin Kim
- Department of Obstetrics and Gynecology, Korea University Guro Hospital, South Korea
| | - Amin Tamadon
- Department of Obstetrics and Gynecology, College of Medicine, Seoul National University, Seoul, South Korea
| | - Hyun Tae Park
- Department of Obstetrics and Gynecology, Korea University Anam Hospital, Korea University College of Medicine, South Korea
| | - Hoon Kim
- Department of Obstetrics and Gynecology, College of Medicine, Seoul National University, Seoul, South Korea
| | - Seung-Yup Ku
- Department of Obstetrics and Gynecology, College of Medicine, Seoul National University, Seoul, South Korea
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8
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Rana K, Chiu MWS, Russell PK, Skinner JP, Lee NKL, Fam BC, Zajac JD, MacLean HE. Muscle-specific androgen receptor deletion shows limited actions in myoblasts but not in myofibers in different muscles in vivo. J Mol Endocrinol 2016; 57:125-38. [PMID: 27402875 DOI: 10.1530/jme-15-0320] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Accepted: 07/04/2016] [Indexed: 11/08/2022]
Abstract
The aim of this study was to investigate the direct muscle cell-mediated actions of androgens by comparing two different mouse lines. The cre-loxP system was used to delete the DNA-binding activity of the androgen receptor (AR) in mature myofibers (MCK mAR(ΔZF2)) in one model and the DNA-binding activity of the AR in both proliferating myoblasts and myofibers (α-actin mAR(ΔZF2)) in another model. We found that hind-limb muscle mass was normal in MCK mAR(ΔZF2) mice and that relative mass of only some hind-limb muscles was reduced in α-actin mAR(ΔZF2) mice. This suggests that myoblasts and myofibers are not the major cellular targets mediating the anabolic actions of androgens on male muscle during growth and development. Levator ani muscle mass was decreased in both mouse lines, demonstrating that there is a myofiber-specific effect in this unique androgen-dependent muscle. We found that the pattern of expression of genes including c-myc, Fzd4 and Igf2 is associated with androgen-dependent changes in muscle mass; therefore, these genes are likely to be mediators of anabolic actions of androgens. Further research is required to identify the major targets of androgen actions in muscle, which are likely to include indirect actions via other tissues.
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Affiliation(s)
- Kesha Rana
- Department of MedicineUniversity of Melbourne, Austin Health, Heidelberg, Victoria, Australia
| | - Maria W S Chiu
- Department of MedicineUniversity of Melbourne, Austin Health, Heidelberg, Victoria, Australia
| | - Patricia K Russell
- Department of MedicineUniversity of Melbourne, Austin Health, Heidelberg, Victoria, Australia
| | - Jarrod P Skinner
- Department of MedicineUniversity of Melbourne, Austin Health, Heidelberg, Victoria, Australia
| | - Nicole K L Lee
- Department of MedicineUniversity of Melbourne, Austin Health, Heidelberg, Victoria, Australia
| | - Barbara C Fam
- Department of MedicineUniversity of Melbourne, Austin Health, Heidelberg, Victoria, Australia
| | - Jeffrey D Zajac
- Department of MedicineUniversity of Melbourne, Austin Health, Heidelberg, Victoria, Australia
| | - Helen E MacLean
- Department of MedicineUniversity of Melbourne, Austin Health, Heidelberg, Victoria, Australia
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Rana K, Lee NKL, Zajac JD, MacLean HE. Expression of androgen receptor target genes in skeletal muscle. Asian J Androl 2015; 16:675-83. [PMID: 24713826 PMCID: PMC4215656 DOI: 10.4103/1008-682x.122861] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
We aimed to determine the mechanisms of the anabolic actions of androgens in skeletal muscle by investigating potential androgen receptor (AR)-regulated genes in in vitro and in vivo models. The expression of the myogenic regulatory factor myogenin was significantly decreased in skeletal muscle from testosterone-treated orchidectomized male mice compared to control orchidectomized males, and was increased in muscle from male AR knockout mice that lacked DNA binding activity (ARΔZF2) versus wildtype mice, demonstrating that myogenin is repressed by the androgen/AR pathway. The ubiquitin ligase Fbxo32 was repressed by 12 h dihydrotestosterone treatment in human skeletal muscle cell myoblasts, and c-Myc expression was decreased in testosterone-treated orchidectomized male muscle compared to control orchidectomized male muscle, and increased in ARΔZF2 muscle. The expression of a group of genes that regulate the transition from myoblast proliferation to differentiation, Tceal7, p57Kip2, Igf2 and calcineurin Aa, was increased in ARΔZF2 muscle, and the expression of all but p57Kip2 was also decreased in testosterone-treated orchidectomized male muscle compared to control orchidectomized male muscle. We conclude that in males, androgens act via the AR in part to promote peak muscle mass by maintaining myoblasts in the proliferative state and delaying the transition to differentiation during muscle growth and development, and by suppressing ubiquitin ligase-mediated atrophy pathways to preserve muscle mass in adult muscle.
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Affiliation(s)
- Kesha Rana
- Department of Medicine, Austin Health, University of Melbourne, Heidelberg, Victoria, Australia
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10
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Ipulan LA, Suzuki K, Sakamoto Y, Murashima A, Imai Y, Omori A, Nakagata N, Nishinakamura R, Valasek P, Yamada G. Nonmyocytic androgen receptor regulates the sexually dimorphic development of the embryonic bulbocavernosus muscle. Endocrinology 2014; 155:2467-79. [PMID: 24742196 PMCID: PMC4060183 DOI: 10.1210/en.2014-1008] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
The bulbocavernosus (BC) is a sexually dimorphic muscle observed only in males. Androgen receptor knockout mouse studies show the loss of BC formation. This suggests that androgen signaling plays a vital role in its development. Androgen has been known to induce muscle hypertrophy through satellite cell activation and myonuclei accretion during muscle regeneration and growth. Whether the same mechanism is present during embryonic development is not yet elucidated. To identify the mechanism of sexual dimorphism during BC development, the timing of morphological differences was first established. It was revealed that the BC was morphologically different between male and female mice at embryonic day (E) 16.5. Differences in the myogenic process were detected at E15.5. The male BC possesses a higher number of proliferating undifferentiated myoblasts. To identify the role of androgen signaling in this process, muscle-specific androgen receptor (AR) mutation was introduced, which resulted in no observable phenotypes. Hence, the expression of AR in the BC was examined and found that the AR did not colocalize with any muscle markers such as Myogenic differentiation 1, Myogenin, and paired box transcription factor 7. It was revealed that the mesenchyme surrounding the BC expressed AR and the BC started to express AR at E15.5. AR mutation on the nonmyocytic cells using spalt-like transcription factor 1 (Sall1) Cre driver mouse was performed, which resulted in defective BC formation. It was revealed that the number of proliferating undifferentiated myoblasts was reduced in the Sall1 Cre:AR(L-/Y) mutant embryos, and the adult mutants were devoid of BC. The transition of myoblasts from proliferation to differentiation is mediated by cyclin-dependent kinase inhibitors. An increased expression of p21 was observed in the BC myoblast of the Sall1 Cre:AR(L-/Y) mutant and wild-type female. Altogether this study suggests that the nonmyocytic AR may paracrinely regulate the proliferation of myoblast possibly through inhibiting p21 expression in myoblasts of the BC.
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Affiliation(s)
- Lerrie Ann Ipulan
- Department of Developmental Genetics (L.A.I., K.S., Y.S., A.M., A.O., G.Y.), Institute of Advanced Medicine, and Department of Biology, Wakayama Medical University (WMU), Wakayama 641-8509, Japan; Graduate School of Pharmaceutical Sciences (L.A.I., Y.S.), Division of Reproductive Engineering (N.N.), Center for Animal Resources and Development, Department of Kidney Development (R.N.), Institute of Molecular Embryology and Genetics, Kumamoto University, Kumamoto 860-8555, Japan; Division of Integrative Pathophysiology (Y.I.), Proteo-Science Center, Graduate School of Medicine, Ehime University, Ehime 791-0295, Japan; School of Biological Sciences and Institute for Cardiovascular and Metabolic Research (P.V.), University of Reading, Reading RG6 6UR, United Kingdom; and Institute of Anatomy (P.V.), First Faculty of Medicine, Charles University, 128 00 Prague 2, Czech Republic
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11
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Dubois V, Laurent M, Boonen S, Vanderschueren D, Claessens F. Androgens and skeletal muscle: cellular and molecular action mechanisms underlying the anabolic actions. Cell Mol Life Sci 2012; 69:1651-67. [PMID: 22101547 PMCID: PMC11115174 DOI: 10.1007/s00018-011-0883-3] [Citation(s) in RCA: 94] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2011] [Revised: 10/27/2011] [Accepted: 11/07/2011] [Indexed: 12/14/2022]
Abstract
Androgens increase both the size and strength of skeletal muscle via diverse mechanisms. The aim of this review is to discuss the different cellular targets of androgens in skeletal muscle as well as the respective androgen actions in these cells leading to changes in proliferation, myogenic differentiation, and protein metabolism. Androgens bind and activate a specific nuclear receptor which will directly affect the transcription of target genes. These genes encode muscle-specific transcription factors, enzymes, structural proteins, as well as microRNAs. In addition, anabolic action of androgens is partly established through crosstalk with other signaling molecules such as Akt, myostatin, IGF-I, and Notch. Finally, androgens may also exert non-genomic effects in muscle by increasing Ca(2+) uptake and modulating kinase activities. In conclusion, the anabolic effect of androgens on skeletal muscle is not only explained by activation of the myocyte androgen receptor but is also the combined result of many genomic and non-genomic actions.
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Affiliation(s)
- Vanessa Dubois
- Molecular Endocrinology Laboratory, Department of Molecular Cell Biology, K.U. Leuven, Campus Gasthuisberg, O&N1, Herestraat 49, Leuven, Belgium
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12
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Lee NKL, Skinner JPJ, Zajac JD, MacLean HE. Ornithine decarboxylase is upregulated by the androgen receptor in skeletal muscle and regulates myoblast proliferation. Am J Physiol Endocrinol Metab 2011; 301:E172-9. [PMID: 21505150 DOI: 10.1152/ajpendo.00094.2011] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The aim of this study is to determine if the Odc1 gene, which encodes ornithine decarboxylase (ODC), the rate-limiting enzyme in polyamine biosynthesis, is directly regulated by the androgen receptor (AR) in skeletal muscle myoblasts and if Odc1 regulates myoblast proliferation and differentiation. We previously showed that expression of Odc1 is decreased in muscle from AR knockout male mice. In this study, we show in vivo that Odc1 expression is also decreased >60% in muscle from male muscle-specific AR knockout mice. In normal muscle homeostasis, Odc1 expression is regulated by age and sex, reflecting testosterone levels, as muscle of adult male mice expresses high levels of Odc1 compared with age-matched females and younger males. In vitro, expression of Odc1 is 10- and 1.5-fold higher in proliferating mouse C(2)C(12) and human skeletal muscle myoblasts, respectively, than in differentiated myotubes. Dihydrotestosterone increases Odc1 levels 2.7- and 1.6-fold in skeletal muscle cell myoblasts after 12 and 24 h of treatment, respectively. Inhibition of ODC activity in C(2)C(12) myoblasts by α-difluoromethylornithine decreases myoblast number by 40% and 66% following 48 and 72 h of treatment, respectively. In contrast, overexpression of Odc1 in C(2)C(12) myoblasts results in a 27% increase in cell number vs. control when cells are grown under differentiation conditions for 96 h. This prolonged proliferation is associated with delayed differentiation, with reduced expression of the differentiation markers myogenin and Myf6 in Odc1-overexpressing cells. In conclusion, androgens act via the AR to upregulate Odc1 in skeletal muscle myoblasts, and Odc1 promotes myoblast proliferation and delays differentiation.
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MESH Headings
- Androgens/pharmacology
- Animals
- Cell Differentiation/drug effects
- Cell Proliferation/drug effects
- Cells, Cultured
- Embryo, Mammalian
- Female
- Gene Expression Regulation, Enzymologic/drug effects
- Humans
- Male
- Mice
- Mice, Inbred C57BL
- Mice, Transgenic
- Muscle, Skeletal/drug effects
- Muscle, Skeletal/metabolism
- Muscle, Skeletal/physiology
- Myoblasts, Skeletal/drug effects
- Myoblasts, Skeletal/metabolism
- Myoblasts, Skeletal/physiology
- Ornithine Decarboxylase/genetics
- Ornithine Decarboxylase/metabolism
- Pregnancy
- Receptors, Androgen/metabolism
- Receptors, Androgen/physiology
- Up-Regulation/drug effects
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Affiliation(s)
- Nicole K L Lee
- Department of Medicine, Austin Health, University of Melbourne, Heidelberg, Victoria, Australia
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13
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Serra C, Bhasin S, Tangherlini F, Barton ER, Ganno M, Zhang A, Shansky J, Vandenburgh HH, Travison TG, Jasuja R, Morris C. The role of GH and IGF-I in mediating anabolic effects of testosterone on androgen-responsive muscle. Endocrinology 2011; 152:193-206. [PMID: 21084444 PMCID: PMC3033058 DOI: 10.1210/en.2010-0802] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Testosterone (T) supplementation increases skeletal muscle mass, circulating GH, IGF-I, and im IGF-I expression, but the role of GH and IGF-I in mediating T's effects on the skeletal muscle remains poorly understood. Here, we show that T administration increased body weight and the mass of the androgen-dependent levator ani muscle in hypophysectomized as well as castrated plus hypophysectomized adult male rats. T stimulated the proliferation of primary human skeletal muscle cells (hSKMCs) in vitro, an effect blocked by transfecting hSKMCs with small interference RNA targeting human IGF-I receptor (IGF-IR). In differentiation conditions, T promoted the fusion of hSKMCs into larger myotubes, an effect attenuated by small interference RNA targeting human IGF-IR. Notably, MKR mice, which express a dominant negative form of the IGF-IR in skeletal muscle fibers, treated with a GnRH antagonist (acyline) to suppress endogenous T, responded to T administration by an attenuated increase in the levator ani muscle mass. In conclusion, circulating GH and IGF-I are not essential for mediating T's effects on an androgen-responsive skeletal muscle. IGF-I signaling plays an important role in mediating T's effects on skeletal muscle progenitor cell growth and differentiation in vitro. However, IGF-IR signaling in skeletal muscle fibers does not appear to be obligatory for mediating the anabolic effects of T on the mass of androgen-responsive skeletal muscles in mice.
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Affiliation(s)
- Carlo Serra
- Section of Endocrinology, Diabetes, and Nutrition, Boston Medical Center, 670 Albany Street, Boston, Massachusetts 02118, USA.
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14
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Lee DM, Lee KH, Cheon YP, Chun TH, Choi IH. Effects of Anabolic Steroids of Pork on Proliferation and Differentiation of Myogenic Satellite Cell. Korean J Food Sci Anim Resour 2010. [DOI: 10.5851/kosfa.2010.30.5.842] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
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15
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Wu Y, Bauman WA, Blitzer RD, Cardozo C. Testosterone-induced hypertrophy of L6 myoblasts is dependent upon Erk and mTOR. Biochem Biophys Res Commun 2010; 400:679-83. [DOI: 10.1016/j.bbrc.2010.08.127] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2010] [Accepted: 08/27/2010] [Indexed: 01/09/2023]
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16
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Current Opinion in Endocrinology, Diabetes & Obesity. Current world literature. Curr Opin Endocrinol Diabetes Obes 2010; 17:293-312. [PMID: 20418721 DOI: 10.1097/med.0b013e328339f31e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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17
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MacLean HE, Handelsman DJ. Unraveling androgen action in muscle: genetic tools probing cellular mechanisms. Endocrinology 2009; 150:3437-9. [PMID: 19622777 DOI: 10.1210/en.2009-0438] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Affiliation(s)
- Helen E MacLean
- Department of Medicine, Austin Health, University of Melbourne, Heidelberg 3084, Victoria, Australia
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