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Sakai H, Imai Y. Cell-specific functions of androgen receptor in skeletal muscles. Endocr J 2024; 71:437-445. [PMID: 38281756 DOI: 10.1507/endocrj.ej23-0691] [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] [Indexed: 01/30/2024] Open
Abstract
Androgens play a vital role not only in promoting the development of male sexual characteristics but also in exerting diverse physiological effects, including the regulation of skeletal muscle growth and function. Given that the effects of androgens are mediated through androgen receptor (AR) binding, an understanding of AR functionality is crucial for comprehending the mechanisms of androgen action on skeletal muscles. Drawing from insights gained using conditional knockout mouse models facilitated by Cre/loxP technology, we review the cell-specific functions of AR in skeletal muscles. We focus on three specific cell populations expressing AR within skeletal muscles: skeletal muscle cells, responsible for muscle contraction; satellite cells, which are essential stem cells contributing to the growth and regeneration of skeletal muscles; and mesenchymal progenitors, situated in interstitial areas and playing a crucial role in muscle homeostasis. Furthermore, the indirect effects of androgens on skeletal muscle through extra-muscle tissue are essential, especially for the regulation of skeletal muscle mass. The regulation of genes by AR varies across different cell types and contexts, including homeostasis, regeneration and hypertrophy of skeletal muscles. The varied mechanisms orchestrated by AR collectively influence the physiology of skeletal muscles.
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Affiliation(s)
- Hiroshi Sakai
- Division of Integrative Pathophysiology, Proteo-Science Center, Ehime University, Ehime 791-0295, Japan
- Department of Pathophysiology, Ehime University Graduate School of Medicine, Ehime 791-0295, Japan
| | - Yuuki Imai
- Division of Integrative Pathophysiology, Proteo-Science Center, Ehime University, Ehime 791-0295, Japan
- Department of Pathophysiology, Ehime University Graduate School of Medicine, Ehime 791-0295, Japan
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2
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Barsky ST, Monks DA. Lifespan Effects of Muscle-Specific Androgen Receptor Overexpression on Body Composition of Male and Female Rats. Endocrinology 2024; 165:bqae012. [PMID: 38301268 DOI: 10.1210/endocr/bqae012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Revised: 01/23/2024] [Accepted: 01/26/2024] [Indexed: 02/03/2024]
Abstract
Androgenic actions of gonadal testosterone are thought to be a major mechanism promoting sex differences in body composition across the lifespan. However, this inference is based on studies of androgen receptor (AR) function in late adolescent or emerging adult rodents. Here we assess body composition and AR expression in skeletal muscle of rats at defined ages, comparing wild-type (WT) to transgenic human skeletal actin-driven AR overexpression (HSAAR) rats which overexpress AR in skeletal muscle. Male and female HSAAR and WT Sprague Dawley rats (N = 288) underwent dual-energy x-ray absorptiometry (DXA) scanning and tissue collection at postnatal day (PND) 1, 10, 21, 42, 70, 183, 243, and 365. Expected sex differences in body composition and muscle mass largely onset with puberty (PND-21), with no associated changes to skeletal muscle AR protein. In adulthood, HSAAR increased tibialis anterior (TA) and extensor digitorum longus mass in males, and reduced the expected gain in gonadal fat mass in both sexes. In WT rats, AR protein was reduced in soleus, but not TA, throughout life. Nonetheless, soleus AR protein expression was greater in male rats than female rats at all ages of sexual development, yet only at PND-70 in TA. Overall, despite muscle AR overexpression effects, results are inconsistent with major sex differences in body composition during sexual development being driven by changes in muscle AR, rather suggesting that changes in ligand promote sexual differentiation of body composition during pubertal timing. Nonetheless, increased skeletal muscle AR in adulthood can be sufficient to increase muscle mass in males, and reduce adipose in both sexes.
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Affiliation(s)
- Sabrina Tzivia Barsky
- Department of Cell & Systems Biology, Faculty of Arts & Science, University of Toronto, Toronto, Ontario M5S 3G5, Canada
| | - Douglas Ashley Monks
- Department of Cell & Systems Biology, Faculty of Arts & Science, University of Toronto, Toronto, Ontario M5S 3G5, Canada
- Department of Psychology, Faculty of Arts & Science, University of Toronto Mississauga, Mississauga, Ontario L5L 1C6, Canada
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Roberts MD, McCarthy JJ, Hornberger TA, Phillips SM, Mackey AL, Nader GA, Boppart MD, Kavazis AN, Reidy PT, Ogasawara R, Libardi CA, Ugrinowitsch C, Booth FW, Esser KA. Mechanisms of mechanical overload-induced skeletal muscle hypertrophy: current understanding and future directions. Physiol Rev 2023; 103:2679-2757. [PMID: 37382939 PMCID: PMC10625844 DOI: 10.1152/physrev.00039.2022] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Revised: 06/12/2023] [Accepted: 06/21/2023] [Indexed: 06/30/2023] Open
Abstract
Mechanisms underlying mechanical overload-induced skeletal muscle hypertrophy have been extensively researched since the landmark report by Morpurgo (1897) of "work-induced hypertrophy" in dogs that were treadmill trained. Much of the preclinical rodent and human resistance training research to date supports that involved mechanisms include enhanced mammalian/mechanistic target of rapamycin complex 1 (mTORC1) signaling, an expansion in translational capacity through ribosome biogenesis, increased satellite cell abundance and myonuclear accretion, and postexercise elevations in muscle protein synthesis rates. However, several lines of past and emerging evidence suggest that additional mechanisms that feed into or are independent of these processes are also involved. This review first provides a historical account of how mechanistic research into skeletal muscle hypertrophy has progressed. A comprehensive list of mechanisms associated with skeletal muscle hypertrophy is then outlined, and areas of disagreement involving these mechanisms are presented. Finally, future research directions involving many of the discussed mechanisms are proposed.
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Affiliation(s)
- Michael D Roberts
- School of Kinesiology, Auburn University, Auburn, Alabama, United States
| | - John J McCarthy
- Department of Physiology, College of Medicine, University of Kentucky, Lexington, Kentucky, United States
| | - Troy A Hornberger
- Department of Comparative Biosciences, University of Wisconsin-Madison, Madison, Wisconsin, United States
| | - Stuart M Phillips
- Department of Kinesiology, McMaster University, Hamilton, Ontario, Canada
| | - Abigail L Mackey
- Institute of Sports Medicine Copenhagen, Department of Orthopedic Surgery, Copenhagen University Hospital-Bispebjerg and Frederiksberg, and Department of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark
| | - Gustavo A Nader
- Department of Kinesiology and Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, Pennsylvania, United States
| | - Marni D Boppart
- Department of Kinesiology and Community Health, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States
| | - Andreas N Kavazis
- School of Kinesiology, Auburn University, Auburn, Alabama, United States
| | - Paul T Reidy
- Department of Kinesiology, Nutrition and Health, Miami University, Oxford, Ohio, United States
| | - Riki Ogasawara
- Healthy Food Science Research Group, Cellular and Molecular Biotechnology Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Japan
| | - Cleiton A Libardi
- MUSCULAB-Laboratory of Neuromuscular Adaptations to Resistance Training, Department of Physical Education, Federal University of São Carlos, São Carlos, Brazil
| | - Carlos Ugrinowitsch
- School of Physical Education and Sport, University of São Paulo, São Paulo, Brazil
| | - Frank W Booth
- Department of Biomedical Sciences, University of Missouri, Columbia, Missouri, United States
| | - Karyn A Esser
- Department of Physiology and Aging, College of Medicine, University of Florida, Gainesville, Florida, United States
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4
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Barsky ST, Monks DA. Myocytic androgen receptor overexpression does not affect sex differences in adaptation to chronic endurance exercise. Biol Sex Differ 2022; 13:59. [PMID: 36274144 PMCID: PMC9590152 DOI: 10.1186/s13293-022-00471-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Accepted: 10/06/2022] [Indexed: 12/02/2022] Open
Abstract
Muscle-specific androgen receptor (AR) overexpression (HSAAR transgene) in sedentary male rats results in reduced adiposity, increased mitochondrial enzyme activity, and selective increase in Type 2b myofiber size. Here, we tested chronic endurance exercise interactions with this phenotype in both sexes. Across 9 weeks, rats ran 5×/week on motorized running wheels at increasing speeds and durations. Exercise reduced fat mass in all groups, but sex affected endurance exercise outcomes such that absolute lean mass increased only in females and total body mass decreased only in males. Expected sex differences were observed with males exhibiting greater total body and lean mass; absolute and relative fat mass; bone mineral density; extensor digitorum longus (EDL) myofiber size and glycolytic proportion; but lesser Type 2a and Type 1 myosin expression in tibialis anterior. Observed HSAAR outcomes were not altered by sex, with transgenic rats having greater lean mass, Type 2a myosin expression in soleus, and glycolytic myofiber size in EDL. Tibialis AR content was independently affected by sex, HSAAR, and exercise. No sex differences were observed in tibialis AR expression in wild-type rats, although HSAAR males had greater AR content than HSAAR females. We identified a moderate correlation between AR expression and glycolytic myofiber size, but not whole-body composition. Overall, results suggest myocytic AR overexpression and chronic exercise, despite sharing a similar phenotype to adaptation, are mediated by distinct mechanisms. Further, this study illustrates sex differences in adaptation to chronic endurance exercise, and suggests sex-similarity in the relationship between muscle AR and exercise response. Adaptations in bone, lean, and total mass after forced endurance exercise are sex-dependent in rats. Sex differences in muscle fiber-type size and proportion, lean body mass, and bone density are independent of exercise in rats. Myocytic AR overexpression promotes lean body mass and glycolytic myofiber size in both sexes. Skeletal muscle AR protein is elevated by chronic endurance exercise in rats, and these changes in AR content are correlated with improved glycolytic myofiber size.
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5
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Horwath O, Moberg M, Hirschberg AL, Ekblom B, Apró W. Molecular Regulators of Muscle Mass and Mitochondrial Remodeling Are Not Influenced by Testosterone Administration in Young Women. Front Endocrinol (Lausanne) 2022; 13:874748. [PMID: 35498440 PMCID: PMC9046720 DOI: 10.3389/fendo.2022.874748] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/12/2022] [Accepted: 03/18/2022] [Indexed: 01/07/2023] Open
Abstract
Testosterone (T) administration has previously been shown to improve muscle size and oxidative capacity. However, the molecular mechanisms underlying these adaptations in human skeletal muscle remain to be determined. Here, we examined the effect of moderate-dose T administration on molecular regulators of muscle protein turnover and mitochondrial remodeling in muscle samples collected from young women. Forty-eight healthy, physically active, young women (28 ± 4 years) were assigned in a random double-blind fashion to receive either T (10 mg/day) or placebo for 10-weeks. Muscle biopsies collected before and after the intervention period were divided into sub-cellular fractions and total protein levels of molecular regulators of muscle protein turnover and mitochondrial remodeling were analyzed using Western blotting. T administration had no effect on androgen receptor or 5α-reductase levels, nor on proteins involved in the mTORC1-signaling pathway (mTOR, S6K1, eEF2 and RPS6). Neither did it affect the abundance of proteins associated with proteasomal protein degradation (MAFbx, MuRF-1 and UBR5) and autophagy-lysosomal degradation (AMPK, ULK1 and p62). T administration also had no effect on proteins in the mitochondria enriched fraction regulating mitophagy (Beclin, BNIP3, LC3B-I, LC3B-II and LC3B-II/I ratio) and morphology (Mitofilin), and it did not alter the expression of mitochondrial fission- (FIS1 and DRP1) or fusion factors (OPA1 and MFN2). In summary, these data indicate that improvements in muscle size and oxidative capacity in young women in response to moderate-dose T administration cannot be explained by alterations in total expression of molecular factors known to regulate muscle protein turnover or mitochondrial remodeling.
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Affiliation(s)
- Oscar Horwath
- Department of Physiology, Nutrition and Biomechanics, Åstrand Laboratory, Swedish School of Sport and Health Sciences, Stockholm, Sweden
- *Correspondence: Oscar Horwath,
| | - Marcus Moberg
- Department of Physiology, Nutrition and Biomechanics, Åstrand Laboratory, Swedish School of Sport and Health Sciences, Stockholm, Sweden
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | - Angelica Lindén Hirschberg
- Department of Women´s and Children´s Health, Division of Neonatology, Obstetrics and Gynaecology, Karolinska Institutet, Stockholm, Sweden
- Department of Gynaecology and Reproductive Medicine, Karolinska University Hospital, Stockholm, Sweden
| | - Björn Ekblom
- Department of Physiology, Nutrition and Biomechanics, Åstrand Laboratory, Swedish School of Sport and Health Sciences, Stockholm, Sweden
| | - William Apró
- Department of Physiology, Nutrition and Biomechanics, Åstrand Laboratory, Swedish School of Sport and Health Sciences, Stockholm, Sweden
- Department of Clinical Science, Intervention and Technology, Karolinska Institutet, Stockholm, Sweden
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6
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Fu S, Lin X, Yin L, Wang X. Androgen receptor regulates the proliferation of myoblasts under appropriate or excessive stretch through IGF-1 receptor mediated p38 and ERK1/2 pathways. Nutr Metab (Lond) 2021; 18:85. [PMID: 34526063 PMCID: PMC8444398 DOI: 10.1186/s12986-021-00610-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Accepted: 08/21/2021] [Indexed: 12/23/2022] Open
Abstract
Background Androgen receptor (AR) exerts important roles in exercise-induced alterations of muscle mass, in which the proliferation and differentiation of satellite cells or myoblasts are crucial. Our previous study in C2C12 myoblasts demonstrated that 15% (mimic appropriate exercise) and 20% (mimic excessive exercise) stretches promoted and inhibited the proliferation respectively; and AR played a crucial role in 15% stretch-induced pro-proliferation through IGF-1-modulated PI3K/Akt, p38 and ERK1/2 pathways, but AR’s role in stretches-modulated proliferation of general myoblasts, especially 20% stretch, remains unclear, and the mechanisms need to be further clarified. Methods Firstly, the discrepancy in proliferation and the above indicators between L6 (without AR) and C2C12 (with AR) myoblasts were compared under 15% or 20% stretch. Then the influences of transfection AR or exogenous IGF-1 treatment on proliferation and these indicators were detected in stretched L6 myoblasts. Results (1) Under un-stretched state, the proliferation of L6 was slower than C2C12 cells. Furthermore, AR knockdown in C2C12 myoblasts repressed, while AR overexpression in L6 myoblasts promoted the proliferation. (2) 15% stretch-induced increases in the proliferation and activities of p38 and ERK1/2 were lower in L6 than C2C12 cells; AR overexpression enhanced the proliferation of 15% stretched L6 cells accompanied with the increases of p38 and ERK1/2 activities. (3) 20% stretch-induced anti-proliferation and inhibition of p38 activity were severer in L6 than C2C12 myoblasts; AR overexpression reversed the anti-proliferation of 20% stretch and enhanced p38 activity in L6 myoblasts. (4) In stretched L6 myoblasts, AR overexpression increased IGF-1R level despite no detectable IGF-1; and recombinant IGF-1 increased the proliferation, the level of IGF-1R, and the activities of p38 and ERK1/2 in 15% stretched L6 myoblasts. Conclusions The study demonstrated AR's crucial roles in stretches-regulated proliferation of myoblasts, and increased AR fulfilled 15% stretch's pro-proliferation via activating IGF-1R- p38 and ERK1/2 pathways while decreased AR achieved 20% stretch's anti-proliferation via inhibiting IGF-1R- p38 pathway, which is useful to understand in depth the role and mechanisms of AR in appropriate exercise increasing while excessive exercise decreasing muscle mass.
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Affiliation(s)
- Shaoting Fu
- Department of Exercise Physiology, School of Kinesiology, Shanghai University of Sport, 188 Hengren Road, Yangpu District, Shanghai, 200438, China.,Department of Kinesiology, College of Physical Education, Shanghai Normal University, Shanghai, 200234, China
| | - Xiaojing Lin
- Department of Exercise Physiology, School of Kinesiology, Shanghai University of Sport, 188 Hengren Road, Yangpu District, Shanghai, 200438, China
| | - Lijun Yin
- Department of Exercise Physiology, School of Kinesiology, Shanghai University of Sport, 188 Hengren Road, Yangpu District, Shanghai, 200438, China
| | - Xiaohui Wang
- Department of Exercise Physiology, School of Kinesiology, Shanghai University of Sport, 188 Hengren Road, Yangpu District, Shanghai, 200438, China.
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7
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Sakakibara I, Yanagihara Y, Himori K, Yamada T, Sakai H, Sawada Y, Takahashi H, Saeki N, Hirakawa H, Yokoyama A, Fukada SI, Sawasaki T, Imai Y. Myofiber androgen receptor increases muscle strength mediated by a skeletal muscle splicing variant of Mylk4. iScience 2021; 24:102303. [PMID: 33870126 PMCID: PMC8041868 DOI: 10.1016/j.isci.2021.102303] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Revised: 02/16/2021] [Accepted: 03/10/2021] [Indexed: 12/14/2022] Open
Abstract
Androgens have a robust effect on skeletal muscles to increase muscle mass and strength. The molecular mechanism of androgen/androgen receptor (AR) action on muscle strength is still not well known, especially for the regulation of sarcomeric genes. In this study, we generated androgen-induced hypertrophic model mice, myofiber-specific androgen receptor knockout (cARKO) mice supplemented with dihydrotestosterone (DHT). DHT treatment increased grip strength in control mice but not in cARKO mice. Transcriptome analysis by RNA-seq, using skeletal muscles obtained from control and cARKO mice treated with or without DHT, identified a fast-type muscle-specific novel splicing variant of Myosin light-chain kinase 4 (Mylk4) as a target of AR in skeletal muscles. Mylk4 knockout mice exhibited decreased maximum isometric torque of plantar flexion and passive stiffness of myofibers due to reduced phosphorylation of Myomesin 1 protein. This study suggests that androgen-induced skeletal muscle strength is mediated with Mylk4 and Myomesin 1 axis. DHT increases muscle strength through myofiber AR Myofiber AR increases a fast-type muscle-specific novel splicing variant of Mylk4 MYLK4 regulates muscle strength and muscle stiffness MYLK4 induces phosphorylation of MYOM1
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Affiliation(s)
- Iori Sakakibara
- Division of Integrative Pathophysiology, Proteo-Science Center, Ehime University, Shitsukawa, Toon, Ehime 791-0295, Japan.,Department of Pathophysiology, Ehime University Graduate School of Medicine, Toon, Ehime 791-0295, Japan.,Department of Nutritional Physiology, Institute of Medical Nutrition, Tokushima University Graduate School, Tokushima 770-8503, Japan
| | - Yuta Yanagihara
- Division of Integrative Pathophysiology, Proteo-Science Center, Ehime University, Shitsukawa, Toon, Ehime 791-0295, Japan.,Division of Laboratory Animal Research, Advanced Research Support Center, Ehime University, Toon, Ehime 791-0295, Japan
| | - Koichi Himori
- Graduate School of Health Sciences, Sapporo Medical University, Sapporo, Hokkaido 060-8558, Japan
| | - Takashi Yamada
- Graduate School of Health Sciences, Sapporo Medical University, Sapporo, Hokkaido 060-8558, Japan
| | - Hiroshi Sakai
- Division of Integrative Pathophysiology, Proteo-Science Center, Ehime University, Shitsukawa, Toon, Ehime 791-0295, Japan.,Department of Pathophysiology, Ehime University Graduate School of Medicine, Toon, Ehime 791-0295, Japan
| | - Yuichiro Sawada
- Division of Integrative Pathophysiology, Proteo-Science Center, Ehime University, Shitsukawa, Toon, Ehime 791-0295, Japan.,Department of Urology, Ehime University Graduate School of Medicine, Toon, Ehime 791-0295, Japan
| | - Hirotaka Takahashi
- Division of Cell-Free Sciences, Proteo-Science Center (PROS), Ehime University, Matsuyama, Ehime 790-8577, Japan
| | - Noritaka Saeki
- Division of Integrative Pathophysiology, Proteo-Science Center, Ehime University, Shitsukawa, Toon, Ehime 791-0295, Japan.,Division of Laboratory Animal Research, Advanced Research Support Center, Ehime University, Toon, Ehime 791-0295, Japan
| | - Hiroyuki Hirakawa
- Department of Physiology and Cell Biology, Tokyo Medical and Dental University (TMDU), Graduate School, Tokyo 113-8510, Japan
| | - Atsushi Yokoyama
- Department of Molecular Endocrinology, Tohoku University Graduate School of Medicine, Sendai, Miyagi 980-8575, Japan
| | - So-Ichiro Fukada
- Project for Muscle Stem Cell Biology, Graduate School of Pharmaceutical Sciences, Osaka University, Suita, Osaka 565-0871, Japan
| | - Tatsuya Sawasaki
- Division of Cell-Free Sciences, Proteo-Science Center (PROS), Ehime University, Matsuyama, Ehime 790-8577, Japan
| | - Yuuki Imai
- Division of Integrative Pathophysiology, Proteo-Science Center, Ehime University, Shitsukawa, Toon, Ehime 791-0295, Japan.,Department of Pathophysiology, Ehime University Graduate School of Medicine, Toon, Ehime 791-0295, Japan.,Division of Laboratory Animal Research, Advanced Research Support Center, Ehime University, Toon, Ehime 791-0295, Japan.,Research Unit for Skeletal Health and Diseases, Ehime University, Toon, Ehime 791-0295, Japan
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8
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Iemura S, Kawao N, Akagi M, Kaji H. Role of Dkk2 in the Muscle/bone Interaction of Androgen-Deficient Mice. Exp Clin Endocrinol Diabetes 2020; 129:770-775. [PMID: 33352594 DOI: 10.1055/a-1331-7021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Androgen deficiency is known to cause both osteoporosis and sarcopenia. Myokines, humoral factors secreted from the skeletal muscles, have recently been getting attention as the key factors related to the interactions between muscle and bone. Dickkopf (Dkk) 2 is known as an inhibitor of canonical Wnt/β-catenin signaling, and Wnt/β-catenin signaling is crucial for the maintenance of muscle and bone. The present study was therefore performed to investigate the roles of Dkk2 in the alterations of muscle and bone of androgen-deficient mice with orchidectomy (ORX). ORX significantly enhanced Dkk2 mRNA levels, but not other Dkks and secreted frizzled related proteins, in the soleus muscles of mice. Moreover, ORX enhanced serum Dkk2 levels, but not Dkk2 mRNA levels in the tibial bone tissues, the white adipose tissues and liver of mice. In simple regression analyses, serum Dkk2 levels were negatively related to trabecular bone mineral density at the tibias in mice employed in the experiments. In vitro experiments, testosterone suppressed Dkk2 mRNA levels in mouse muscle C2C12 cells. In conclusion, we showed that androgen deficiency enhances Dkk2 expression and secretion in the muscles of mice. Dkk2 might be involved in androgen deficiency-induced muscle wasting and osteopenia as a myokine linking muscle to bone.
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Affiliation(s)
- Shunki Iemura
- Department of Orthopaedic Surgery, Kindai University Faculty of Medicine, Osakasayama, Japan.,Department of Physiology and Regenerative Medicine, Kindai University Faculty of Medicine, Osakasayama, Japan
| | - Naoyuki Kawao
- Department of Physiology and Regenerative Medicine, Kindai University Faculty of Medicine, Osakasayama, Japan
| | - Masao Akagi
- Department of Orthopaedic Surgery, Kindai University Faculty of Medicine, Osakasayama, Japan
| | - Hiroshi Kaji
- Department of Physiology and Regenerative Medicine, Kindai University Faculty of Medicine, Osakasayama, Japan
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Stantzou A, Relizani K, Morales-Gonzalez S, Gallen C, Grassin A, Ferry A, Schuelke M, Amthor H. Extracellular matrix remodelling is associated with muscle force increase in overloaded mouse plantaris muscle. Neuropathol Appl Neurobiol 2020; 47:218-235. [PMID: 32772401 DOI: 10.1111/nan.12655] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Revised: 07/13/2020] [Accepted: 07/28/2020] [Indexed: 12/31/2022]
Abstract
AIMS Transforming growth factor-β (TGF-β) signalling is thought to contribute to the remodelling of extracellular matrix (ECM) of skeletal muscle and to functional decline in patients with muscular dystrophies. We wanted to determine the role of TGF-β-induced ECM remodelling in dystrophic muscle. METHODS We experimentally induced the pathological hallmarks of severe muscular dystrophy by mechanically overloading the plantaris muscle in mice. Furthermore, we determined the role of TGF-β signalling on dystrophic tissue modulation and on muscle function by (i) overloading myostatin knockout (Mstn-/- ) mice and (ii) by additional pharmacological TGF-β inhibition via halofuginone. RESULTS Transcriptome analysis of overloaded muscles revealed upregulation predominantly of genes associated with ECM, inflammation and metalloproteinase activity. Histology revealed in wild-type mice signs of severe muscular dystrophy including myofibres with large variation in size and internalized myonuclei, as well as increased ECM deposition. At the same time, muscle weight had increased by 208% and muscle force by 234%. Myostatin deficiency blunted the effect of overload on muscle mass (59% increase) and force (76% increase), while having no effect on ECM deposition. Concomitant treatment with halofuginone blunted overload-induced muscle hypertrophy and muscle force increase, while reducing ECM deposition and increasing myofibre size. CONCLUSIONS ECM remodelling is associated with an increase in muscle mass and force in overload-modelled dystrophic muscle. Lack of myostatin is not advantageous and inhibition of ECM deposition by halofuginone is disadvantageous for muscle plasticity in response to stimuli that induce dystrophic muscle.
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Affiliation(s)
- A Stantzou
- Université Paris-Saclay, UVSQ, Inserm, END-ICAP, Versailles, France
| | - K Relizani
- Université Paris-Saclay, UVSQ, Inserm, END-ICAP, Versailles, France.,NeuroCure Cluster of Excellence and Department of Neuropediatrics, Charité-Universitätsmedizin Berlin, Corporate member of the Freie Universität Berlin and Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - S Morales-Gonzalez
- NeuroCure Cluster of Excellence and Department of Neuropediatrics, Charité-Universitätsmedizin Berlin, Corporate member of the Freie Universität Berlin and Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - C Gallen
- Université Paris-Saclay, UVSQ, Inserm, END-ICAP, Versailles, France
| | - A Grassin
- Université Paris-Saclay, UVSQ, Inserm, END-ICAP, Versailles, France
| | - A Ferry
- Center for Research in Myology, Pierre et Marie Curie University, Paris Sorbonne, INSERM, UMRS974, CNRS FRE3617, Paris, France.,Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - M Schuelke
- NeuroCure Cluster of Excellence and Department of Neuropediatrics, Charité-Universitätsmedizin Berlin, Corporate member of the Freie Universität Berlin and Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - H Amthor
- Université Paris-Saclay, UVSQ, Inserm, END-ICAP, Versailles, France
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10
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Ferry A, Messéant J, Parlakian A, Lemaitre M, Roy P, Delacroix C, Lilienbaum A, Hovhannisyan Y, Furling D, Klein A, Li Z, Agbulut O. Desmin prevents muscle wasting, exaggerated weakness and fragility, and fatigue in dystrophic mdx mouse. J Physiol 2020; 598:3667-3689. [PMID: 32515007 DOI: 10.1113/jp279282] [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: 11/08/2019] [Accepted: 06/05/2020] [Indexed: 01/21/2023] Open
Abstract
KEY POINTS Desmin, similar to dystrophin, is associated with costameric structures bridging sarcomeres to the extracellular matrix. Deletion of the desmin gene in mdx mice [double knockout (DKO) mice] induces marked muscle weakness and fatigue resistance compared to mdx mice. Muscle fragility (higher susceptibility to contraction-induced injury) was also aggravated in DKO mice compared to mdx mice. By contrast to mdx mice, the DKO mice did not undergo muscle hypertrophy. Desmin cDNA transfer with adeno-associated virus in newborn mdx mice reduced muscle weakness. Overall, desmin plays important and beneficial roles in muscle wasting, performance and fragility in dystrophic muscle. ABSTRACT Duchenne muscular dystrophy (DMD) is a severe neuromuscular disease caused by dystrophin deficiency. Desmin, similar to dystrophin, is associated with costameric structures bridging sarcomeres to the extracellular matrix that contributes to muscle function. In the present study, we attempted to provide further insight into the roles of desmin, for which the expression is increased in the muscle from the mouse mdx DMD model. We show that a deletion of the desmin gene (Des) in mdx mice [double knockout (DKO) mice, mdx:desmin-/-] induces a marked muscle weakness; namely, a reduced absolute maximal force production and increased fatigue compared to that in mdx mice. Fragility (i.e. higher susceptibility to contraction-induced injury) was also aggravated in DKO mice compared to mdx mice, despite the promotion of supposedly less fragile muscle fibres in DKO mice, and this worsening of fragility was related to a decreased muscle excitability. Moreover, in contrast to mdx mice, the DKO mice did not undergo muscle hypertrophy, as indicated by smaller and fewer fibres, with a reduced percentage of centronucleated fibres, potentially explaining the severe muscle weakness. Notably, Desmin cDNA transfer with adeno-associated virus in newborn mdx mice improved specific maximal force normalized to muscle weight. Overall, desmin plays important and beneficial roles in muscle wasting, performance and fragility in dystrophic mdx mice, which differ, at least in part, from those observed in healthy muscle.
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Affiliation(s)
- Arnaud Ferry
- Sorbonne Université, Centre de recherche en myologie, INSERM U974, Institut de Myologie, Paris, France.,Université de Paris, Institut des Sciences du Sport Santé de Paris, UFRSTAPS, Paris, France
| | - Julien Messéant
- Sorbonne Université, Centre de recherche en myologie, INSERM U974, Institut de Myologie, Paris, France
| | - Ara Parlakian
- Sorbonne Université, Institut de Biologie Paris-Seine (IBPS), UMR CNRS 8256, INSERM ERL U1164, Biological Adaptation and Ageing, Paris, France
| | - Mégane Lemaitre
- Sorbonne Université, Centre de recherche en myologie, INSERM U974, Institut de Myologie, Paris, France
| | - Pauline Roy
- Sorbonne Université, Centre de recherche en myologie, INSERM U974, Institut de Myologie, Paris, France
| | - Clément Delacroix
- Sorbonne Université, Centre de recherche en myologie, INSERM U974, Institut de Myologie, Paris, France
| | - Alain Lilienbaum
- Université de Paris, Unité de Biologie Fonctionnelle et Adaptative, CNRS UMR 8251, Paris, France
| | - Yeranuhi Hovhannisyan
- Sorbonne Université, Institut de Biologie Paris-Seine (IBPS), UMR CNRS 8256, INSERM ERL U1164, Biological Adaptation and Ageing, Paris, France
| | - Denis Furling
- Sorbonne Université, Centre de recherche en myologie, INSERM U974, Institut de Myologie, Paris, France
| | - Arnaud Klein
- Sorbonne Université, Centre de recherche en myologie, INSERM U974, Institut de Myologie, Paris, France
| | - Zhenlin Li
- Sorbonne Université, Institut de Biologie Paris-Seine (IBPS), UMR CNRS 8256, INSERM ERL U1164, Biological Adaptation and Ageing, Paris, France
| | - Onnik Agbulut
- Sorbonne Université, Institut de Biologie Paris-Seine (IBPS), UMR CNRS 8256, INSERM ERL U1164, Biological Adaptation and Ageing, Paris, France
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11
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Reitzner SM, Hengevoss J, Isenmann E, Diel P. Modulation of exercise training related adaptation of body composition and regulatory pathways by anabolic steroids. J Steroid Biochem Mol Biol 2019; 190:44-53. [PMID: 30926427 DOI: 10.1016/j.jsbmb.2019.03.023] [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: 02/28/2019] [Revised: 03/25/2019] [Accepted: 03/25/2019] [Indexed: 10/27/2022]
Abstract
Anabolic steroids have a long history of abuse in amateur and professional athletics. However, their interaction with training and the resulting effects on body composition and tissue adaptation, relying on a concert of factors and pathways, remain under investigation. This study aims at investigating the changes of body composition and the expression of selected genes and pathways essential for this adaptation process. Therefore, male wistar rats were treated with the anabolic steroid metandienone in two groups (n = 16; metandienone, metandienone + exercise) alongside with control groups (n = 16; control, exercise). Following a 6-week steep-angle treadmill training protocol, weight of organs, visceral fat and muscles was determined. M. gastrocnemius was histologically assessed by ATPase staining, mRNA and protein levels of factors of regeneration, hypertrophy and myogenesis and selected master regulators and markers were determined. Results show additive effects of anabolic steroids and exercise on body, tibia and reproductive organs weight. Mm. gastrocnemius and soleus weight was increased by training but not anabolic steroids. Muscle fiber diameter and composition remained unchanged. Visceral fat mass and fat cell size was affected by training and anabolic steroids but no additive effects could be observed. Exercise and anabolic steroids result in a complex regulation of the expression of genes in M. Gastrocnemius involved in skeletal muscle metabolism, hypertrophy, inflammation and regeneration. In summary, our data suggests distinct molecular mechanisms involved in the adaptation of the skeletal muscle to anabolic androgenic steroids and exercise. Metandienone treatment neither results in skeletal muscle hypertrophy nor liver-toxic effects but in an induction of skeletal muscle regeneration and an activation of endocrine negative feedback. Moreover our study demonstrates that visceral fat and bone responds with higher sensitivity to ASS and exercise than the skeletal muscle. This apparent plasticity of adipose and bone tissue rather than skeletal muscle could indicate a potentially superior future role of fat rather than muscle related parameters to detect and AAS abuse in a biologic passport strategy in professional athletes.
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Affiliation(s)
| | - Jonas Hengevoss
- Department of Molecular and Cellular Sport Medicine, German Sport University Cologne, Germany
| | - Eduard Isenmann
- Department of Molecular and Cellular Sport Medicine, German Sport University Cologne, Germany
| | - Patrick Diel
- Department of Molecular and Cellular Sport Medicine, German Sport University Cologne, Germany
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12
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Jardí F, Laurent MR, Dubois V, Kim N, Khalil R, Decallonne B, Vanderschueren D, Claessens F. Androgen and estrogen actions on male physical activity: a story beyond muscle. J Endocrinol 2018; 238:R31-R52. [PMID: 29743340 DOI: 10.1530/joe-18-0125] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Accepted: 05/09/2018] [Indexed: 12/15/2022]
Abstract
Physical inactivity is a pandemic that contributes to several chronic diseases and poses a significant burden on health care systems worldwide. The search for effective strategies to combat sedentary behavior has led to an intensification of the research efforts to unravel the biological substrate controlling activity. A wide body of preclinical evidence makes a strong case for sex steroids regulating physical activity in both genders, albeit the mechanisms implicated remain unclear. The beneficial effects of androgens on muscle as well as on other peripheral functions might play a role in favoring adaptation to exercise. Alternatively or in addition, sex steroids could act on specific brain circuitries to boost physical activity. This review critically discusses the evidence supporting a role for androgens and estrogens stimulating male physical activity, with special emphasis on the possible role of peripheral and/or central mechanisms. Finally, the potential translation of these findings to humans is briefly discussed.
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Affiliation(s)
- Ferran Jardí
- Clinical and Experimental EndocrinologyDepartment of Chronic Diseases, Metabolism and Ageing (CHROMETA), KU Leuven, Leuven, Belgium
| | - Michaël R Laurent
- Molecular Endocrinology LaboratoryDepartment of Cellular and Molecular Medicine, KU Leuven, Leuven, Belgium
- Gerontology and GeriatricsDepartment of Chronic Diseases, Metabolism and Ageing (CHROMETA), KU Leuven, Leuven, Belgium
| | - Vanessa Dubois
- Molecular Endocrinology LaboratoryDepartment of Cellular and Molecular Medicine, KU Leuven, Leuven, Belgium
| | - Nari Kim
- Clinical and Experimental EndocrinologyDepartment of Chronic Diseases, Metabolism and Ageing (CHROMETA), KU Leuven, Leuven, Belgium
| | - Rougin Khalil
- Clinical and Experimental EndocrinologyDepartment of Chronic Diseases, Metabolism and Ageing (CHROMETA), KU Leuven, Leuven, Belgium
| | - Brigitte Decallonne
- Clinical and Experimental EndocrinologyDepartment of Chronic Diseases, Metabolism and Ageing (CHROMETA), KU Leuven, Leuven, Belgium
| | - Dirk Vanderschueren
- Clinical and Experimental EndocrinologyDepartment of Chronic Diseases, Metabolism and Ageing (CHROMETA), KU Leuven, Leuven, Belgium
| | - Frank Claessens
- Molecular Endocrinology LaboratoryDepartment of Cellular and Molecular Medicine, KU Leuven, Leuven, Belgium
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Krause Neto W, de Assis Silva W, Polican Ciena A, Bocalini D, Aparecido Baptista Nucci R, Alberto Anaruma C, Florencio Gama E. Total training load may explain similar strength gains and muscle hypertrophy seen in aged rats submitted to resistance training and anabolic steroids. Aging Male 2018; 21:65-76. [PMID: 28817355 DOI: 10.1080/13685538.2017.1365832] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
This study aimed to quantify training parameters and analyze the morphological response of aged muscles submitted to resistance training and anabolic steroids. Aged Wistar rats were divided into groups: C - initial control; CF - final control; CAS - control with anabolic steroid, RT - resistance training, and RTA - resistance training with anabolic steroid. Maximum carried load, absolute and relative loads increased significantly in RT and RTA. RTA demonstrated greater relative load than RT. Average total volume, total climbing volume, relative total volume, relative total climbing volume, and mean climbing volume were similar between groups RT and RTA. For soleus, CAS, RT, and RTA enlarged cross-sectional area of type I fibers and nuclear ratio. As for type II fibers, RTA was higher than C and CF. For plantaris, RT and RTA showed significant increases in myofibers type I compared to C and CF. For type II fibers, RTA showed a significant increase compared to C and CF. Regarding the nuclear ratio, RT and RTA showed a higher ratio than C, CF, and CAS. Our results demonstrated that both RT and RTA were not different among the analyzed morphological parameters. This fact can be explained by the absence of differences found in the training variables analyzed.
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Affiliation(s)
- Walter Krause Neto
- a Department of Physical Education, Laboratory of Morphoquantitative Studies and Immunohistochemistry , São Judas Tadeu University , São Paulo , Brazil
| | - Wellington de Assis Silva
- a Department of Physical Education, Laboratory of Morphoquantitative Studies and Immunohistochemistry , São Judas Tadeu University , São Paulo , Brazil
| | - Adriano Polican Ciena
- b Department of Physical Education, Laboratory of Morphology and Physical Activity , São Paulo State University "Júlio de Mesquita Filho" , Rio Claro , Brazil
| | - Danilo Bocalini
- c Translational Physiology Laboratory, Physical Education and Aging Science Program , São Judas Tadeu University , São Paulo , Brazil
| | - Ricardo Aparecido Baptista Nucci
- a Department of Physical Education, Laboratory of Morphoquantitative Studies and Immunohistochemistry , São Judas Tadeu University , São Paulo , Brazil
| | - Carlos Alberto Anaruma
- b Department of Physical Education, Laboratory of Morphology and Physical Activity , São Paulo State University "Júlio de Mesquita Filho" , Rio Claro , Brazil
| | - Eliane Florencio Gama
- a Department of Physical Education, Laboratory of Morphoquantitative Studies and Immunohistochemistry , São Judas Tadeu University , São Paulo , Brazil
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14
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Ueberschlag-Pitiot V, Stantzou A, Messéant J, Lemaitre M, Owens DJ, Noirez P, Roy P, Agbulut O, Metzger D, Ferry A. Gonad-related factors promote muscle performance gain during postnatal development in male and female mice. Am J Physiol Endocrinol Metab 2017; 313:E12-E25. [PMID: 28351832 DOI: 10.1152/ajpendo.00446.2016] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/13/2016] [Revised: 02/22/2017] [Accepted: 03/22/2017] [Indexed: 11/22/2022]
Abstract
To better define the role of male and female gonad-related factors (MGRF, presumably testosterone, and FGRF, presumably estradiol, respectively) on mouse hindlimb skeletal muscle contractile performance/function gain during postnatal development, we analyzed the effect of castration initiated before puberty in male and female mice. We found that muscle absolute and specific (normalized to muscle weight) maximal forces were decreased in 6-mo-old male and female castrated mice compared with age- and sex-matched intact mice, without alteration in neuromuscular transmission. Moreover, castration decreased absolute and specific maximal powers, another important aspect of muscle performance, in 6-mo-old males, but not in females. Absolute maximal force was similarly reduced by castration in 3-mo-old muscle fiber androgen receptor (AR)-deficient and wild-type male mice, indicating that the effect of MGRF was muscle fiber AR independent. Castration reduced the muscle weight gain in 3-mo mice of both sexes and in 6-mo females but not in males. We also found that bone morphogenetic protein signaling through Smad1/5/9 was not altered by castration in atrophic muscle of 3-mo-old mice of both sexes. Moreover, castration decreased the sexual dimorphism regarding muscle performance. Together, these results demonstrated that in the long term, MGRF and FGRF promote muscle performance gain in mice during postnatal development, independently of muscle growth in males, largely via improving muscle contractile quality (force and power normalized), and that MGFR and FGRF also contribute to sexual dimorphism. However, the mechanisms underlying MGFR and FGRF actions remain to be determined.
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Affiliation(s)
- Vanessa Ueberschlag-Pitiot
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Université de Strasbourg, CNRS UMR7104/INSERM U964, Illkirch, France
| | - Amalia Stantzou
- Sorbonne Universités, Université Pierre et Marie Curie-Paris6, Myology Research Center, UM76 and INSERM U974 and CNRS FRE 3617 and Institut de Myologie, Paris, France
| | - Julien Messéant
- Sorbonne Universités, Université Pierre et Marie Curie-Paris6, Myology Research Center, UM76 and INSERM U974 and CNRS FRE 3617 and Institut de Myologie, Paris, France
| | - Megane Lemaitre
- Sorbonne Universités, Université Pierre et Marie Curie-Paris6, Myology Research Center, UM76 and INSERM U974 and CNRS FRE 3617 and Institut de Myologie, Paris, France
| | - Daniel J Owens
- Sorbonne Universités, Université Pierre et Marie Curie-Paris6, Myology Research Center, UM76 and INSERM U974 and CNRS FRE 3617 and Institut de Myologie, Paris, France
| | - Philippe Noirez
- Institut de Recherche Biomédicale et D'épidemiologie du Sport, EA 7329, Institut National du Sport de l'Expertise et de la Performance, Laboratory of Excellence GR-Ex, Paris, France
- Université Sorbonne Paris Cité, Université Paris Descartes, Paris, France; and
| | - Pauline Roy
- Sorbonne Universités, Université Pierre et Marie Curie-Paris6, Myology Research Center, UM76 and INSERM U974 and CNRS FRE 3617 and Institut de Myologie, Paris, France
| | - Onnik Agbulut
- Sorbonne Universités, Université Pierre et Marie Curie-Paris6, Institut de Biologie Paris-Seine, UMR CNRS 8256, Biological Adaptation and Ageing, Paris, France
| | - Daniel Metzger
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Université de Strasbourg, CNRS UMR7104/INSERM U964, Illkirch, France
| | - Arnaud Ferry
- Sorbonne Universités, Université Pierre et Marie Curie-Paris6, Myology Research Center, UM76 and INSERM U974 and CNRS FRE 3617 and Institut de Myologie, Paris, France;
- Université Sorbonne Paris Cité, Université Paris Descartes, Paris, France; and
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15
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Rodrigues JM, Oliveira VPP, P Furlan J, Munhoz AC, S Rempel MR, Brito MN, Brito NA, Pedrosa MMD, M Costa CE. Immediate and residual effects of low-dose nandrolone decanoate and treadmill training on adipose and reproductive tissues of male Wistar rats. Arch Physiol Biochem 2017; 123:68-77. [PMID: 28019124 DOI: 10.1080/13813455.2016.1260592] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
CONTEXT Residual effects after nandrolone decanoate (ND) treatment are not reported. OBJECTIVE Immediate and residual effects of low-dose ND and treadmill training were investigated. MATERIALS AND METHODS Male rats were trained and/or ND-treated for four weeks and the assessments were made after this period or four weeks later. RESULTS The groups did not differ in final plasma glucose or AUC of the ivGTT, but hyperinsulinemia was noticed in some trained/treated groups. Training with ND increased muscle mass and ND decreased the reproductive structures. Decreased fat with training was reversed by detraining. DISCUSSION The anabolic action of ND on skeletal muscle was enhanced by training. Fat and lipid changes were more linked to training/detraining, but the effects of ND on the reproductive structures persisted after treatment. CONCLUSIONS The effects of training on fat and muscle were not maintained after detraining, but low-dose ND had persistent effects on the reproductive structures.
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Affiliation(s)
- Josilene M Rodrigues
- a Academic Specialization in Physiology, State University of Maringá , Maringá, Brazil
| | - Vinicius P P Oliveira
- a Academic Specialization in Physiology, State University of Maringá , Maringá, Brazil
| | - Julia P Furlan
- b Undergraduation in Physical Education, State University of Maringá , Maringá, Brazil
| | - Ana Claudia Munhoz
- c Undergraduation in Biological Sciences, State University of Maringá , Maringá, Brazil
| | - Marcelo R S Rempel
- d Undergraduation in Medicine, State University of Maringá , Maringá, Brazil , and
| | - Marcia N Brito
- e Department of Physiological Sciences , State University of Maringá , Maringá, Brazil
| | - Nilton A Brito
- e Department of Physiological Sciences , State University of Maringá , Maringá, Brazil
| | - Maria M D Pedrosa
- e Department of Physiological Sciences , State University of Maringá , Maringá, Brazil
| | - Cecília E M Costa
- e Department of Physiological Sciences , State University of Maringá , Maringá, Brazil
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Egner IM, Bruusgaard JC, Gundersen K. An apparent lack of effect of satellite cell depletion on hypertrophy could be due to methodological limitations. Response to ‘Methodological issues limit interpretation of negative effects of satellite cell depletion on adult muscle hypertrophy’. Development 2017; 144:1365-1367. [DOI: 10.1242/dev.148163] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- Ingrid M. Egner
- Department of Biosciences, University of Oslo, Blindern, Oslo N-0316, Norway
| | - Jo C. Bruusgaard
- Department of Biosciences, University of Oslo, Blindern, Oslo N-0316, Norway
- Department of Health Sciences, Kristiania University College, P.O. Box 1190, Sentrum, Oslo N-0107, Norway
| | - Kristian Gundersen
- Department of Biosciences, University of Oslo, Blindern, Oslo N-0316, Norway
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17
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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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