1
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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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Hatt AA, Kamal M, Mikhail AI, Fortino SA, Wageh M, Kumbhare D, Parise G. Nuclear-localized androgen receptor content following resistance exercise training is associated with hypertrophy in males but not females. FASEB J 2024; 38:e23403. [PMID: 38197297 DOI: 10.1096/fj.202301291rr] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Revised: 12/13/2023] [Accepted: 12/18/2023] [Indexed: 01/11/2024]
Abstract
Androgen receptor (AR) content has been implicated in the differential response between high and low responders following resistance exercise training (RET). However, the influence of AR expression on acute skeletal muscle damage and whether it may influence the adaptive response to RET in females is poorly understood. Thus, the purpose of this exploratory examination was to 1) investigate changes in AR content during skeletal muscle repair and 2) characterize AR-mediated sex-based differences following RET. A skeletal muscle biopsy from the vastus lateralis was obtained from 26 healthy young men (n = 13) and women (n = 13) at baseline and following 300 eccentric kicks. Subsequently, participants performed 10 weeks of full-body RET and a final muscle biopsy was collected. In the untrained state, AR mRNA expression was associated with paired box protein-7 (PAX7) mRNA in males. For the first time in human skeletal muscle, we quantified AR content in the myofiber and localized to the nucleus where AR has been shown to trigger cellular outcomes related to growth. Upon eccentric damage, nuclear-associated AR (nAR) content increased (p < .05) in males and not females. Males with the greatest increase in cross-sectional area (CSA) post-RET had more (p < .05) nAR content than females with the greatest gain CSA. Collectively, skeletal muscle damage and RET increased AR protein, and both gene and hypertrophy measures revealed sex differences in relation to AR. These findings suggest that AR content but more importantly, nuclear localization, is a factor that differentiates RET-induced hypertrophy between males and females.
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Affiliation(s)
- Aidan A Hatt
- Department of Kinesiology, Faculty of Science, McMaster University, Hamilton, Ontario, Canada
| | - Michael Kamal
- Department of Kinesiology, Faculty of Science, McMaster University, Hamilton, Ontario, Canada
| | - Andrew I Mikhail
- Department of Kinesiology, Faculty of Science, McMaster University, Hamilton, Ontario, Canada
| | - Stephen A Fortino
- Department of Kinesiology, Faculty of Science, McMaster University, Hamilton, Ontario, Canada
| | - Mai Wageh
- Department of Kinesiology, Faculty of Science, McMaster University, Hamilton, Ontario, Canada
| | - Dinesh Kumbhare
- Department of Medicine, Division of Physical Medicine and Rehabilitation, Toronto Rehabilitation Institute, Toronto, Ontario, Canada
| | - Gianni Parise
- Department of Kinesiology, Faculty of Science, McMaster University, Hamilton, Ontario, Canada
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3
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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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Kumar V, Sari AN, Gupta D, Ishida Y, Terao K, Kaul SC, Vrati S, Sundar D, Wadhwa R. Anti-COVID-19 Potential of Withaferin-A and Caffeic Acid Phenethyl Ester. Curr Top Med Chem 2024; 24:830-842. [PMID: 38279743 DOI: 10.2174/0115680266280720231221100004] [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: 10/13/2023] [Revised: 11/15/2023] [Accepted: 12/05/2023] [Indexed: 01/28/2024]
Abstract
BACKGROUND The recent COVID-19 (coronavirus disease 2019) pandemic triggered research on the development of new vaccines/drugs, repurposing of clinically approved drugs, and assessment of natural anti-COVID-19 compounds. Based on the gender difference in the severity of the disease, such as a higher number of men hospitalized and in intense care units, variations in sex hormones have been predicted to play a role in disease susceptibility. Cell surface receptors (Angiotensin-Converting Enzyme 2; ACE2 and a connected transmembrane protease serine 2- TMPSS2) are upregulated by androgens. Conversely, androgen antagonists have also been shown to lower ACE2 levels, implying their usefulness in COVID-19 management. OBJECTIVES In this study, we performed computational and cell-based assays to investigate the anti- COVID-19 potential of Withaferin-A and Caffeic acid phenethyl ester, natural compounds from Withania somnifera and honeybee propolis, respectively. METHODS Structure-based computational approach was adopted to predict binding stability, interactions, and dynamics of the two test compounds to three target proteins (androgen receptor, ACE2, and TMPRSS2). Further, in vitro, cell-based experimental approaches were used to investigate the effect of compounds on target protein expression and SARS-CoV-2 replication. RESULTS Computation and experimental analyses revealed that (i) CAPE, but not Wi-A, can act as androgen antagonist and hence inhibit the transcriptional activation function of androgen receptor, (ii) while both Wi-A and CAPE could interact with ACE2 and TMPRSS2, Wi-A showed higher binding affinity, and (iii) combination of Wi-A and CAPE (Wi-ACAPE) caused strong downregulation of ACE2 and TMPRSS2 expression and inhibition of virus infection. CONCLUSION Wi-A and CAPE possess multimodal anti-COVID-19 potential, and their combination (Wi-ACAPE) is expected to provide better activity and hence warrant further attention in the laboratory and clinic.
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Affiliation(s)
- Vipul Kumar
- DAILAB, Department of Biochemical Engineering & Biotechnology, Indian Institute of Technology (IIT) Delhi, Hauz Khas, New Delhi, 110 016, India
| | - Anissa Nofita Sari
- AIST-INDIA DAILAB, National Institute of Advanced Industrial Science & Technology (AIST), Tsukuba, 305 8565, Japan
| | - Dharmender Gupta
- Regional Centre for Biotechnology (RCB), Faridabad, 121 001, India
| | - Yoshiyuki Ishida
- CycloChem Bio Co., Ltd., 7-4-5 Minatojima-minamimachi, Kobe, 6500047, Japan
| | - Keiji Terao
- CycloChem Bio Co., Ltd., 7-4-5 Minatojima-minamimachi, Kobe, 6500047, Japan
| | - Sunil C Kaul
- AIST-INDIA DAILAB, National Institute of Advanced Industrial Science & Technology (AIST), Tsukuba, 305 8565, Japan
| | - Sudhanshu Vrati
- Regional Centre for Biotechnology (RCB), Faridabad, 121 001, India
| | - Durai Sundar
- DAILAB, Department of Biochemical Engineering & Biotechnology, Indian Institute of Technology (IIT) Delhi, Hauz Khas, New Delhi, 110 016, India
| | - Renu Wadhwa
- AIST-INDIA DAILAB, National Institute of Advanced Industrial Science & Technology (AIST), Tsukuba, 305 8565, Japan
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5
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Barsky ST, Monks DA. Androgen action on myogenesis throughout the lifespan; comparison with neurogenesis. Front Neuroendocrinol 2023; 71:101101. [PMID: 37669703 DOI: 10.1016/j.yfrne.2023.101101] [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: 04/28/2023] [Revised: 08/31/2023] [Accepted: 09/02/2023] [Indexed: 09/07/2023]
Abstract
Androgens' pleiotropic actions in promoting sex differences present not only a challenge to providing a comprehensive account of their function, but also an opportunity to gain insights by comparing androgenic actions across organ systems. Although often overlooked by neuroscientists, skeletal muscle is another androgen-responsive organ system which shares with the nervous system properties of electrochemical excitability, behavioral relevance, and remarkable capacity for adaptive plasticity. Here we review androgenic regulation of mitogenic plasticity in skeletal muscle with the goal of identifying areas of interest to those researching androgenic mechanisms mediating sexual differentiation of neurogenesis. We use an organizational-activational framework to relate broad areas of similarity and difference between androgen effects on mitogenesis in muscle and brain throughout the lifespan, from early organogenesis, through pubertal organization, adult activation, and aging. The focus of the review is androgenic regulation of muscle-specific stem cells (satellite cells), which share with neural stem cells essential functions in development, plasticity, and repair, albeit with distinct, muscle-specific features. Also considered are areas of paracrine and endocrine interaction between androgen action on muscle and nervous system, including mediation of neural plasticity of innervating and distal neural populations by muscle-produced trophic factors.
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Affiliation(s)
- Sabrina Tzivia Barsky
- Department of Cell & Systems Biology, Faculty of Arts & Science, University of Toronto, Toronto, Ontario, Canada.
| | - Douglas Ashley Monks
- Department of Cell & Systems Biology, Faculty of Arts & Science, University of Toronto, Toronto, Ontario, Canada; Department of Psychology, Faculty of Arts & Science, University of Toronto Mississauga, Mississauga, Ontario, Canada.
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6
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Morris E, Abreu A, Scordilis SP. Effect of Tamoxifen on Proteome Expression during In Vitro Myogenesis in Murine Skeletal Muscle C 2C 12 Cells. J Proteome Res 2023; 22:3040-3053. [PMID: 37552804 PMCID: PMC10476267 DOI: 10.1021/acs.jproteome.3c00340] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2023] [Indexed: 08/10/2023]
Abstract
Tamoxifen (TMX), a selective estrogen receptor modulator, is commonly used in the treatment of hormone-responsive cancers. However, the effects of TMX in anabolic tissues harboring estrogen receptors, such as skeletal muscle, are poorly understood. We report a tandem mass-tag approach to TMX-treated myogenesis in C2C12 cells, a well-characterized model of in vitro murine skeletal muscle differentiation. A longitudinal analysis of >10,000 proteins identified in untreated C2C12 myogenesis revealed a novel subset of 1,062 myogenically regulated proteins. These proteins clustered into five distinct longitudinal expression trends which significantly overlap those obtained in similar analyses performed in human myocytes. We document a specific functional enrichment for adiponectin-signaling unique to TMX-treated myogenesis, as well as a subset of 198 proteins that are differentially expressed in TMX-treated cells relative to controls at one or more stages of myogenesis, the majority of which were involved in steroid and lipid metabolism. Further analysis highlights metallothionein-1 as a novel target of TMX treatment at each stage of C2C12 myogenesis. Finally, we present a powerful, self-validating pipeline for analyzing the total proteomic response to in vitro treatment across every stage of muscle cell development which can be easily adapted to study the effects of other drugs on myogenesis.
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Affiliation(s)
- Emily
A. Morris
- Department
of Microbiology and Immunology, Geisel School
of Medicine at Dartmouth, Borwell Building 644E, Lebanon, New Hampshire 03756, United States
| | - Ahlenne Abreu
- Department
of Cancer Biology, Perelman School of Medicine,
University of Pennsylvania Medical School, 421 Curie Blvd. Room 612 BRB II/III, Philadelphia, Pennsylvania 19104, United States
| | - Stylianos P. Scordilis
- Department
of Biological Sciences, Smith College, Ford Hall 202 B, Northampton, Massachusetts 01063, United States
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7
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Bensreti H, Yu K, Alhamad DW, Shaver J, Kaiser H, Zhong R, Whichard WC, Parker E, Grater L, Faith H, Johnson M, Cooley MA, Fulzele S, Hill WD, Isales CM, Hamrick MW, McGee-Lawrence ME. Orchiectomy sensitizes cortical bone in male mice to the harmful effects of kynurenine. Bone 2023; 173:116811. [PMID: 37244427 PMCID: PMC10330684 DOI: 10.1016/j.bone.2023.116811] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Revised: 05/17/2023] [Accepted: 05/19/2023] [Indexed: 05/29/2023]
Abstract
Kynurenine (Kyn) is a tryptophan metabolite that increases with age and promotes musculoskeletal dysfunction. We previously found a sexually dimorphic pattern in how Kyn affects bone, with harmful effects more prevalent in females than males. This raises the possibility that male sex steroids might exert a protective effect that blunts the effects of Kyn in males. To test this, orchiectomy (ORX) or sham surgeries were performed on 6-month-old C57BL/6 mice, after which mice received Kyn (10 mg/kg) or vehicle via intraperitoneal injection, once daily, 5×/week, for four weeks. Bone histomorphometry, DXA, microCT, and serum marker analyses were performed after sacrifice. In vitro studies were performed to specifically test the effect of testosterone on activation of aryl hydrocarbon receptor (AhR)-mediated signaling by Kyn in mesenchymal-lineage cells. Kyn treatment reduced cortical bone mass in ORX- but not sham-operated mice. Trabecular bone was unaffected. Kyn's effects on cortical bone in ORX mice were attributed primarily to enhanced endosteal bone resorption activity. Bone marrow adipose tissue was increased in Kyn-treated ORX animals but was unchanged by Kyn in sham-operated mice. ORX surgery increased mRNA expression of the aryl hydrocarbon receptor (AhR) and its target gene Cyp1a1 in the bone, suggesting a priming and/or amplification of AhR signaling pathways. Mechanistic in vitro studies revealed that testosterone blunted Kyn-stimulated AhR transcriptional activity and Cyp1a1 expression in mesenchymal-linage cells. These data suggest a protective role for male sex steroids in blunting the harmful effects of Kyn in cortical bone. Therefore, testosterone may play an important role in regulating Kyn/AhR signaling in musculoskeletal tissues, suggesting crosstalk between male sex steroids and Kyn signaling may influence age-associated musculoskeletal frailty.
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Affiliation(s)
- Husam Bensreti
- Department of Cellular Biology and Anatomy, Medical College of, Georgia at Augusta University, Augusta, GA, United States of America
| | - Kanglun Yu
- Department of Cellular Biology and Anatomy, Medical College of, Georgia at Augusta University, Augusta, GA, United States of America
| | - Dima W Alhamad
- Department of Cellular Biology and Anatomy, Medical College of, Georgia at Augusta University, Augusta, GA, United States of America
| | - Joseph Shaver
- Department of Cellular Biology and Anatomy, Medical College of, Georgia at Augusta University, Augusta, GA, United States of America
| | - Helen Kaiser
- Biomedical Sciences, University of South Carolina School of Medicine Greenville, Greenville, SC, United States of America
| | - Roger Zhong
- Department of Neuroscience & Regenerative Medicine, Medical College of, Georgia at Augusta University, Augusta, GA, United States of America
| | - William C Whichard
- Department of Cellular Biology and Anatomy, Medical College of, Georgia at Augusta University, Augusta, GA, United States of America
| | - Emily Parker
- Department of Cellular Biology and Anatomy, Medical College of, Georgia at Augusta University, Augusta, GA, United States of America
| | - Lindsey Grater
- Department of Cellular Biology and Anatomy, Medical College of, Georgia at Augusta University, Augusta, GA, United States of America
| | - Hayden Faith
- Department of Cellular Biology and Anatomy, Medical College of, Georgia at Augusta University, Augusta, GA, United States of America
| | - Maribeth Johnson
- Department of Neuroscience & Regenerative Medicine, Medical College of, Georgia at Augusta University, Augusta, GA, United States of America
| | - Marion A Cooley
- Department of Oral Biology & Diagnostic Sciences, Dental Collage of Georgia at Augusta University, Augusta, GA, United States of America
| | - Sadanand Fulzele
- Department of Cellular Biology and Anatomy, Medical College of, Georgia at Augusta University, Augusta, GA, United States of America
| | - William D Hill
- Department of Pathology, Medical University of South Carolina, Charleston, SC, United States of America
| | - Carlos M Isales
- Department of Neuroscience & Regenerative Medicine, Medical College of, Georgia at Augusta University, Augusta, GA, United States of America
| | - Mark W Hamrick
- Department of Cellular Biology and Anatomy, Medical College of, Georgia at Augusta University, Augusta, GA, United States of America
| | - Meghan E McGee-Lawrence
- Department of Cellular Biology and Anatomy, Medical College of, Georgia at Augusta University, Augusta, GA, United States of America.
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8
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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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9
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Krause JS, Watkins T, Reid AMA, Cheah JC, Pérez JH, Bishop VR, Ramenofsky M, Wingfield JC, Meddle SL. Gene expression of sex steroid metabolizing enzymes and receptors in the skeletal muscle of migrant and resident subspecies of white-crowned sparrow (Zonotrichia leucophrys). Oecologia 2022; 199:549-562. [PMID: 35732927 DOI: 10.1007/s00442-022-05204-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Accepted: 05/27/2022] [Indexed: 10/17/2022]
Abstract
Circulating sex steroid concentrations vary dramatically across the year in seasonally breeding animals. The ability of circulating sex steroids to effect muscle function can be modulated by changes in intracellular expression of steroid metabolizing enzymes (e.g., 5α-reductase type 2 and aromatase) and receptors. Together, these combined changes in plasma hormones, metabolizing enzymes and receptors allow for seasonally appropriate changes in skeletal muscle function. We tested the hypothesis that gene expression of sex steroid metabolizing enzymes and receptors would vary seasonally in skeletal muscle and these changes would differ between a migrant and resident life history strategy. We quantified annual changes in plasma testosterone and gene expression in pectoralis and gastrocnemius skeletal muscles using quantitative polymerase chain reaction (qPCR) in free-living migrant (Zonotrichia leucophrys gambelii) and resident (Z. l. nuttalli) subspecies of white-crowned sparrow during breeding, pre-basic molt, and wintering life history stages. Pectoralis muscle profile was largest in migrants during breeding, while residents maintained large muscle profiles year-round. Circulating testosterone peaked during breeding in both subspecies. Pectoralis muscle androgen receptor mRNA expression was lower in females of both subspecies during breeding. Estrogen receptor-α expression was higher in the pectoralis muscle, but not gastrocnemius, of residents throughout the annual cycle when compared to migrants. Pectoralis aromatase expression was higher in resident males compared to migrant males. No differences were observed for 5α-reductase 2. Between these two subspecies, patterns of plasma testosterone and androgen receptors appear to be conserved, however estrogen receptor gene expression appears to have diverged.
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Affiliation(s)
- Jesse S Krause
- Department of Biology, University of Nevada Reno, 1664 N. Virginia Street, Sarah Fleischmann 109, Reno, NV, 89557, USA. .,Department of Neurobiology Physiology Behavior, University of California, Davis, CA, 95616, USA.
| | - Trevor Watkins
- Department of Biology, University of Nevada Reno, 1664 N. Virginia Street, Sarah Fleischmann 109, Reno, NV, 89557, USA
| | - Angus M A Reid
- Institute of Genetics and Molecular Medicine, University of Edinburgh, Crewe Road South, Edinburgh, EH4 2XU, Scotland, UK.,The Roslin Institute, University of Edinburgh, Midlothian, EH25 9RG, Scotland, UK
| | - Jeffrey C Cheah
- Department of Neurobiology Physiology Behavior, University of California, Davis, CA, 95616, USA
| | - Jonathan H Pérez
- Department of Biology, University of South Alabama, Mobile, AL, 36688, USA
| | - Valerie R Bishop
- The Roslin Institute, University of Edinburgh, Midlothian, EH25 9RG, Scotland, UK
| | - Marilyn Ramenofsky
- Department of Neurobiology Physiology Behavior, University of California, Davis, CA, 95616, USA
| | - John C Wingfield
- Department of Neurobiology Physiology Behavior, University of California, Davis, CA, 95616, USA
| | - Simone L Meddle
- The Roslin Institute, University of Edinburgh, Midlothian, EH25 9RG, Scotland, UK
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10
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Rossetti ML, Dunlap KR, Salazar G, Hickner RC, Kim JS, Chase BP, Miller BF, Gordon BS. Systemic delivery of a mitochondria targeted antioxidant partially preserves limb muscle mass and grip strength in response to androgen deprivation. Mol Cell Endocrinol 2021; 535:111391. [PMID: 34245847 PMCID: PMC8403153 DOI: 10.1016/j.mce.2021.111391] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Revised: 06/21/2021] [Accepted: 07/06/2021] [Indexed: 10/20/2022]
Abstract
Muscle mass is important for health. Decreased testicular androgen production (hypogonadism) contributes to the loss of muscle mass, with loss of limb muscle being particularly debilitating. Androgen replacement is the only pharmacological treatment, which may not be feasible for everyone. Prior work showed that markers of reactive oxygen species and markers of mitochondrial degradation pathways were higher in the limb muscle following castration. Therefore, we tested whether an antioxidant preserved limb muscle mass in male mice subjected to a castration surgery. Subsets of castrated mice were treated with resveratrol (a general antioxidant) or MitoQ (a mitochondria targeted antioxidant). Relative to the non-castrated control mice, lean mass, limb muscle mass, and grip strength were partially preserved only in castrated mice treated with MitoQ. Independent of treatment, markers of mitochondrial degradation pathways remained elevated in all castrated mice. Therefore, a mitochondrial targeted antioxidant may partially preserve limb muscle mass in response to hypogonadism.
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Affiliation(s)
- Michael L Rossetti
- Department of Nutrition and Integrative Physiology, Florida State University, Tallahassee, FL, USA
| | - Kirsten R Dunlap
- Department of Nutrition and Integrative Physiology, Florida State University, Tallahassee, FL, USA
| | - Gloria Salazar
- Department of Nutrition and Integrative Physiology, Florida State University, Tallahassee, FL, USA
| | - Robert C Hickner
- Department of Nutrition and Integrative Physiology, Florida State University, Tallahassee, FL, USA; Institute of Sports Sciences and Medicine, Florida State University, Tallahassee, FL, USA
| | - Jeong-Su Kim
- Department of Nutrition and Integrative Physiology, Florida State University, Tallahassee, FL, USA; Institute of Sports Sciences and Medicine, Florida State University, Tallahassee, FL, USA
| | - Bryant P Chase
- Department of Biological Science, Florida State University, Tallahassee, FL, USA
| | - Benjamin F Miller
- Aging & Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA
| | - Bradley S Gordon
- Department of Nutrition and Integrative Physiology, Florida State University, Tallahassee, FL, USA; Institute of Sports Sciences and Medicine, Florida State University, Tallahassee, FL, USA.
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Gordon BS, Rossetti ML, Casero RA. Spermidine is not an independent factor regulating limb muscle mass in mice following androgen deprivation. Appl Physiol Nutr Metab 2021; 46:452-460. [PMID: 33125852 DOI: 10.1139/apnm-2020-0404] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Maintaining a critical amount of skeletal muscle mass is linked to reduced morbidity and mortality. In males, testicular androgens regulate muscle mass with a loss of androgens being critical as it is associated with muscle atrophy. Atrophy of the limb muscles is particularly important, but the pathways by which androgens regulate limb muscle mass remain equivocal. We used microarray analysis to identify changes to genes involved with polyamine metabolism in the tibialis anterior (TA) muscle of castrated mice. Of the polyamines, the concentration of spermidine (SPD) was significantly reduced in the TA of castrated mice. To assess whether SPD was an independent factor by which androgens regulate limb muscle mass, we treated castrated mice with SPD for 8 weeks and compared them with sham operated mice. Though this treatment paradigm effectively restored SPD concentrations in the TA muscles of castrated mice, mass of the limb muscles (i.e., TA, gastrocnemius, plantaris, and soleus) were not increased to the levels observed in sham animals. Consistent with those findings, muscle force production was also not increased by SPD treatment. Overall, these data demonstrate for the first time that SPD is not an independent factor by which androgens regulate limb skeletal muscle mass. Novelty: Polyamines regulate growth in various cells/tissues. Spermidine concentrations are reduced in the limb skeletal muscle following androgen depletion. Restoring spermidine concentrations in the limb skeletal muscle does not increase limb muscle mass or force production.
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Affiliation(s)
- Bradley S Gordon
- Department of Nutrition, Food and Exercise Science, Florida State University, Tallahassee, FL 32306, USA
- Institute of Sports Sciences and Medicine, Florida State University, Tallahassee, FL 32306, USA
| | - Michael L Rossetti
- Department of Nutrition, Food and Exercise Science, Florida State University, Tallahassee, FL 32306, USA
| | - Robert A Casero
- Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
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Stancampiano MR, Lucas-Herald AK, Russo G, Rogol AD, Ahmed SF. Testosterone Therapy in Adolescent Boys: The Need for a Structured Approach. Horm Res Paediatr 2020; 92:215-228. [PMID: 31851967 DOI: 10.1159/000504670] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/07/2019] [Accepted: 11/09/2019] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND In adolescents, testosterone may have several effects including promotion of secondary sexual characteristics and pubertal growth, attainment of optimal muscle mass and peak bone mass, optimization of the metabolic profile, and psychosocial maturation and well-being. SUMMARY Testosterone therapy is a cornerstone of the management of hypogonadism in boys. Since the initial report of the chemical synthesis of testosterone, several formulations have continued to develop, and although many of these have been used in boys, none of them have been studied in detail in this age group. Given the wide ranging effects of testosterone, the level of evidence for their effects in boys and the heterogeneity of conditions that lead to early-onset hypogonadism, a standardized protocol for monitoring testosterone replacement in this age group is needed. Key Messages: In this review, we focus on the perceived benefits of androgen replacement in boys affected by pubertal delay and highlight the need to improve the health monitoring of boys who receive androgen replacement therapy, proposing different approaches based on the underlying pathophysiology.
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Affiliation(s)
- Marianna Rita Stancampiano
- Department of Pediatrics, Endocrine Unit, Scientific Institute San Raffaele, Milan, Italy, .,Developmental Endocrinology Research Group, University of Glasgow, Glasgow, United Kingdom,
| | - Angela K Lucas-Herald
- Developmental Endocrinology Research Group, University of Glasgow, Glasgow, United Kingdom
| | - Gianni Russo
- Department of Pediatrics, Endocrine Unit, Scientific Institute San Raffaele, Milan, Italy
| | - Alan D Rogol
- Department of Pediatrics, University of Virginia, Charlottesville, Virginia, USA
| | - S Faisal Ahmed
- Developmental Endocrinology Research Group, University of Glasgow, Glasgow, United Kingdom
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13
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Rossetti ML, Esser KA, Lee C, Tomko RJ, Eroshkin AM, Gordon BS. Disruptions to the limb muscle core molecular clock coincide with changes in mitochondrial quality control following androgen depletion. Am J Physiol Endocrinol Metab 2019; 317:E631-E645. [PMID: 31361545 PMCID: PMC6842919 DOI: 10.1152/ajpendo.00177.2019] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Androgen depletion in humans leads to significant atrophy of the limb muscles. However, the pathways by which androgens regulate limb muscle mass are unclear. Our laboratory previously showed that mitochondrial degradation was related to the induction of autophagy and the degree of muscle atrophy following androgen depletion, implying that decreased mitochondrial quality contributes to muscle atrophy. To increase our understanding of androgen-sensitive pathways regulating decreased mitochondrial quality, total RNA from the tibialis anterior of sham and castrated mice was subjected to microarray analysis. Using this unbiased approach, we identified significant changes in the expression of genes that compose the core molecular clock. To assess the extent to which androgen depletion altered the limb muscle clock, the tibialis anterior muscles from sham and castrated mice were harvested every 4 h throughout a diurnal cycle. The circadian expression patterns of various core clock genes and known clock-controlled genes were disrupted by castration, with most genes exhibiting an overall reduction in phase amplitude. Given that the core clock regulates mitochondrial quality, disruption of the clock coincided with changes in the expression of genes involved with mitochondrial quality control, suggesting a novel mechanism by which androgens may regulate mitochondrial quality. These events coincided with an overall increase in mitochondrial degradation in the muscle of castrated mice and an increase in markers of global autophagy-mediated protein breakdown. In all, these data are consistent with a novel conceptual model linking androgen depletion-induced limb muscle atrophy to reduced mitochondrial quality control via disruption of the molecular clock.
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Affiliation(s)
- Michael L Rossetti
- Department of Nutrition, Food and Exercise Sciences, Florida State University, Tallahassee, Florida
| | - Karyn A Esser
- Department of Physiology and Functional Genomics, University of Florida, Gainesville, Florida
| | - Choogon Lee
- Department of Biomedical Sciences, Florida State University College of Medicine, Tallahassee, Florida
| | - Robert J Tomko
- Department of Biomedical Sciences, Florida State University College of Medicine, Tallahassee, Florida
| | - Alexey M Eroshkin
- Sanford Burnham Prebys Medical Discovery Institute, La Jolla, California
- Rancho BioSciences, San Diego, California
| | - Bradley S Gordon
- Department of Nutrition, Food and Exercise Sciences, Florida State University, Tallahassee, Florida
- Institute of Sports Sciences and Medicine, Florida State University, Tallahassee, Florida
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14
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Rosa-Caldwell ME, Greene NP. Muscle metabolism and atrophy: let's talk about sex. Biol Sex Differ 2019; 10:43. [PMID: 31462271 PMCID: PMC6714453 DOI: 10.1186/s13293-019-0257-3] [Citation(s) in RCA: 124] [Impact Index Per Article: 24.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Accepted: 08/16/2019] [Indexed: 02/07/2023] Open
Abstract
Skeletal muscle health is a strong predictor of overall health and longevity. Pathologies affecting skeletal muscle such as cancer cachexia, intensive care unit treatment, muscular dystrophies, and others are associated with decreased quality of life and increased mortality. Recent research has begun to determine that these muscular pathologies appear to present and develop differently between males and females. However, to our knowledge, there has yet to be a comprehensive review on musculoskeletal differences between males and females and how these differences may contribute to sex differences in muscle pathologies. Herein, we present a review of the current literature on muscle phenotype and physiology between males and females and how these differences may contribute to differential responses to atrophic stimuli. In general, females appear to be more susceptible to disuse induced muscle wasting, yet protected from inflammation induced (such as cancer cachexia) muscle wasting compared to males. These differences may be due in part to differences in muscle protein turnover, satellite cell content and proliferation, hormonal interactions, and mitochondrial differences between males and females. However, more works specifically examining muscle pathologies in females are necessary to more fully understand the inherent sex-based differences in muscle pathologies between the sexes and how they may correspond to different clinical treatments.
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Affiliation(s)
- Megan E Rosa-Caldwell
- Integrative Muscle Metabolism Laboratory, Exercise Science Research Center, Department of Human Health Performance and Recreation, University of Arkansas, Fayetteville, AR, 72701, USA
| | - Nicholas P Greene
- Integrative Muscle Metabolism Laboratory, Exercise Science Research Center, Department of Human Health Performance and Recreation, University of Arkansas, Fayetteville, AR, 72701, USA.
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15
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Clarke MV, Russell PK, Zajac JD, Davey RA. The androgen receptor in the hypothalamus positively regulates hind-limb muscle mass and voluntary physical activity in adult male mice. J Steroid Biochem Mol Biol 2019; 189:187-194. [PMID: 30853652 DOI: 10.1016/j.jsbmb.2019.02.018] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Revised: 02/28/2019] [Accepted: 02/28/2019] [Indexed: 10/27/2022]
Abstract
We have previously shown that expression of the androgen receptor (AR) in neurons within the brain positively regulates hind-limb muscle mass and physical activity in male mice. To further investigate the region of the brain responsible for mediating these effects of testosterone and to determine whether they are only important for muscle mass accrual during development or whether they are also important for the maintenance of muscle mass in the adult, we deleted the AR specifically in the hypothalamus of adult male mice (Hyp-ARKOs). Hyp-ARKO mice were generated by bilateral stereotaxic microinjection of an adeno-associated virus (AAV) expressing GFP and iCre recombinase under the control of the e-synapsin promoter into the hypothalamus of 10-week-old exon 3-AR floxed male mice. AR mRNA was deleted by 45% in the hypothalamus of Hyp-ARKOs at 5 weeks post-AAV-eSyn-iCre injection. This led to an increase in the mass of the androgen-dependent organs, seminal vesicles and kidneys, by 30% (P < 0.01) and 10% (P < 0.05) respectively, and an increase in serum luteinizing hormone (LH) by 2 fold (P < 0.05). Whilst the mean value for serum testosterone was higher in the Hyp-ARKOs, this did not reach statistical significance. Despite a phenotype consistent with increased androgen bioactivity in Hyp-ARKOs, which would be expected to increase muscle mass, the mass of the hind-limb muscles, gastrocnemius (Gast) (P = 0.001), extensor digitorum longus (EDL) (P < 0.001) and soleus (Sol) (P < 0.01) were paradoxically decreased by 12-19% compared to controls. Voluntary physical activity was reduced by 65% (P < 0.05) in Hyp-ARKO male mice and was associated with a reduction in gene expression of Drd1a and Maob (P ≤ 0.05) in the hypothalamus, suggesting involvement of the brain dopaminergic system. These data provide compelling evidence that androgen signalling via the AR in the hypothalamus acts to positively regulate the maintenance of hind-limb muscle mass and voluntary activity in adult male mice, independent of AR signalling in peripheral tissues.
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Affiliation(s)
- Michele V Clarke
- Department of Medicine, Austin Health, The University of Melbourne, Heidelberg, Victoria, 3084, Australia
| | - Patricia K Russell
- Department of Medicine, Austin Health, The University of Melbourne, Heidelberg, Victoria, 3084, Australia
| | - Jeffrey D Zajac
- Department of Medicine, Austin Health, The University of Melbourne, Heidelberg, Victoria, 3084, Australia
| | - Rachel A Davey
- Department of Medicine, Austin Health, The University of Melbourne, Heidelberg, Victoria, 3084, Australia.
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16
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Rossetti ML, Steiner JL, Gordon BS. Increased mitochondrial turnover in the skeletal muscle of fasted, castrated mice is related to the magnitude of autophagy activation and muscle atrophy. Mol Cell Endocrinol 2018; 473:178-185. [PMID: 29378237 DOI: 10.1016/j.mce.2018.01.017] [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] [Received: 12/11/2017] [Revised: 01/22/2018] [Accepted: 01/23/2018] [Indexed: 01/07/2023]
Abstract
Androgen-deficiency promotes muscle atrophy in part by increasing autophagy-mediated muscle protein breakdown during the fasted state, but factors contributing to this remain undefined. To identify novel factors, mice were subjected to sham or castration surgery. Seven-weeks post-surgery, mice were fasted overnight, refed for 30 min, and fasted another 4.5 h before sacrifice. BNIP3-mediated turnover of mitochondria was increased within the atrophied tibialis anterior (TA) of castrated mice and related to the magnitude of muscle atrophy and autophagy activation (i.e. decreased p62 protein content), thus linking turnover of potentially dysfunctional mitochondria with autophagy-mediated atrophy. Autophagy induction was likely facilitated by AMPK activation as a stress survival mechanism since phosphorylation of AMPK (Thr172), as well as the pro survival kinases Akt (Thr308) and (ERK1/2 Thr202/Tyr204), were increased by castration. Together, these data identify a novel relationship between mitochondrial turnover in the fasted state with autophagy activation and muscle atrophy following androgen depletion.
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Affiliation(s)
- Michael L Rossetti
- Department of Nutrition, Food & Exercise Sciences, Florida State University, 600 W. College Ave, Tallahassee, FL 32306, United States
| | - Jennifer L Steiner
- Department of Nutrition, Food & Exercise Sciences, Florida State University, 600 W. College Ave, Tallahassee, FL 32306, United States
| | - Bradley S Gordon
- Department of Nutrition, Food & Exercise Sciences, Florida State University, 600 W. College Ave, Tallahassee, FL 32306, United States.
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17
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Botulinum Toxin Induced Atrophy: An Uncharted Territory. Toxins (Basel) 2018; 10:toxins10080313. [PMID: 30072597 PMCID: PMC6115806 DOI: 10.3390/toxins10080313] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2018] [Revised: 07/30/2018] [Accepted: 07/31/2018] [Indexed: 11/29/2022] Open
Abstract
Botulinum neurotoxins (BoNTs) produce local chemo-denervation by cleaving soluble N-ethylmaleimide-sensitive factor activating protein receptor (SNARE) proteins. Botulinum neurotoxins are therapeutically indicated in several neurological disorders and have been in use for three decades. The long-term efficacy, safety, and side effects of BoNTs have been well documented in the literature. However, the development of muscle atrophy following chronic exposure to BoNTs has not received sufficient attention. Muscle atrophy is not only cosmetically distressing, but also has an impact on future injections. An extensive literature search was conducted on atrophy and mechanisms of atrophy. Five hundred and four relevant articles in the English language were reviewed. This review revealed the surprising lack of documentation of atrophy within the literature. In addition, as demonstrated in this review, the mechanisms and the clinical factors that may lead to atrophy have also been poorly studied. However, even with this limited information it is possible to indicate factors that could modify the clinical approach to botulinum toxin injections. This review highlights the need for further study of atrophy following BoNT injections.
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18
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Rossetti ML, Fukuda DH, Gordon BS. Androgens induce growth of the limb skeletal muscles in a rapamycin-insensitive manner. Am J Physiol Regul Integr Comp Physiol 2018; 315:R721-R729. [PMID: 29897818 DOI: 10.1152/ajpregu.00029.2018] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Signaling through the mechanistic target of rapamycin complex 1 (mTORC1) has been well defined as an androgen-sensitive transducer mediating skeletal muscle growth in vitro; however, this has yet to be tested in vivo. As such, male mice were subjected to either sham or castration surgery and allowed to recover for 7 wk to induce atrophy of skeletal muscle. Then, castrated mice were implanted with either a control pellet or a pellet that administered rapamycin (~2.5 mg·kg-1·day-1). Seven days postimplant, a subset of castrated mice with control pellets and all castrated mice with rapamycin pellets were given once weekly injections of nandrolone decanoate (ND) to induce muscle growth over a six-week period. Effective blockade of mTORC1 by rapamycin was noted in the skeletal muscle by the inability of insulin to induce phosphorylation of ribosomal S6 kinase 1 70 kDa (Thr389) and uncoordinated-like kinase 1 (Ser757). While castration reduced tibialis anterior (TA) mass, muscle fiber cross-sectional area, and total protein content, ND administration restored these measures to sham levels in a rapamycin-insensitive manner. Similar findings were also observed in the plantaris and soleus, suggesting this rapamycin-insensitive effect was not specific to the TA or fiber type. Androgen-mediated growth was not due to changes in translational capacity. Despite these findings in the limb skeletal muscle, rapamycin completely prevented the ND-mediated growth of the heart. In all, these data indicate that mTORC1 has a limited role in the androgen-mediated growth of the limb skeletal muscle; however, mTORC1 was necessary for androgen-mediated growth of heart muscle.
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Affiliation(s)
- Michael L Rossetti
- Department of Nutrition, Food, and Exercise Sciences, Florida State University , Tallahassee, Florida
| | - David H Fukuda
- Institute of Exercise Physiology and Wellness, University of Central Florida , Orlando, Florida
| | - Bradley S Gordon
- Department of Nutrition, Food, and Exercise Sciences, Florida State University , Tallahassee, Florida
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19
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20
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Takayama KI. The biological and clinical advances of androgen receptor function in age-related diseases and cancer [Review]. Endocr J 2017; 64:933-946. [PMID: 28824023 DOI: 10.1507/endocrj.ej17-0328] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Hormonal alterations with aging contribute to the pathogenesis of several diseases. Androgens mediate their effects predominantly through binding to the androgen receptor (AR), a member of the ligand-dependent nuclear receptor superfamily. By androgen treatment, AR is recruited to specific genomic loci dependent on tissue specific pioneer factors to regulate target gene expression. Recent studies have revealed the epigenetic modulation by AR-associated histone modifiers and the roles of non-coding RNAs in AR signaling. Androgens are male sex hormone to induce differentiation of the male reproductive system required for the establishment of adult sexual function. As shown by several reports using AR knockout mouse models, androgens also have anabolic functions in several tissues such as bone, muscle and central nervous systems. Notably, AR has a central role in prostate cancer progression. Prostate cancer is the most frequently diagnosed cancer in men. Androgen-deprivation therapy for cancer patients and decline of serum androgen with aging promote several diseases associated with aging and quality of life of older men such as osteoporosis, sarcopenia and dementia. Thus, androgen replacement therapy for treating late onset hypogonadism (LOH) or new epigenetic regulators have the potential to overcome the symptoms caused by the low androgen, although adverse effects for cardiovascular diseases have been reported. Given the increasing longevity and consequent rise of age-related diseases and prostate cancer patients, a more understanding of the AR actions in male health remains a high research priority.
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Affiliation(s)
- Ken-Ichi Takayama
- Department of Functional Biogerontology, Tokyo Metropolitan Institute of Gerontology, Itabashi-ku, Tokyo 173-0015, Japan
- Department of Geriatric Medicine, Graduate School of Medicine, the University of Tokyo, Japan
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21
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Davey RA, Clarke MV, Russell PK, Rana K, Seto J, Roeszler KN, How JMY, Chia LY, North K, Zajac JD. Androgen Action via the Androgen Receptor in Neurons Within the Brain Positively Regulates Muscle Mass in Male Mice. Endocrinology 2017; 158:3684-3695. [PMID: 28977603 DOI: 10.1210/en.2017-00470] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Accepted: 07/25/2017] [Indexed: 11/19/2022]
Abstract
Although it is well established that exogenous androgens have anabolic effects on skeletal muscle mass in humans and mice, data from muscle-specific androgen receptor (AR) knockout (ARKO) mice indicate that myocytic expression of the AR is dispensable for hind-limb muscle mass accrual in males. To identify possible indirect actions of androgens via the AR in neurons to regulate muscle, we generated neuron-ARKO mice in which the dominant DNA binding-dependent actions of the AR are deleted in neurons of the cortex, forebrain, hypothalamus, and olfactory bulb. Serum testosterone and luteinizing hormone levels were elevated twofold in neuron-ARKO males compared with wild-type littermates due to disruption of negative feedback to the hypothalamic-pituitary-gonadal axis. Despite this increase in serum testosterone levels, which was expected to increase muscle mass, the mass of the mixed-fiber gastrocnemius (Gast) and the fast-twitch fiber extensor digitorum longus hind-limb muscles was decreased by 10% in neuron-ARKOs at 12 weeks of age, whereas muscle strength and fatigue of the Gast were unaffected. The mass of the soleus muscle, however, which consists of a high proportion of slow-twitch fibers, was unaffected in neuron-ARKOs, demonstrating a stimulatory action of androgens via the AR in neurons to increase the mass of fast-twitch hind-limb muscles. Furthermore, neuron-ARKOs displayed reductions in voluntary and involuntary physical activity by up to 60%. These data provide evidence for a role of androgens via the AR in neurons to positively regulate fast-twitch hind-limb muscle mass and physical activity in male mice.
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Affiliation(s)
- Rachel A Davey
- Department of Medicine, Austin Health, University of Melbourne, Heidelberg, Victoria 3084, Australia
| | - Michele V Clarke
- Department of Medicine, Austin Health, University of Melbourne, Heidelberg, Victoria 3084, Australia
| | - Patricia K Russell
- Department of Medicine, Austin Health, University of Melbourne, Heidelberg, Victoria 3084, Australia
| | - Kesha Rana
- Department of Medicine, Austin Health, University of Melbourne, Heidelberg, Victoria 3084, Australia
| | - Jane Seto
- Murdoch Children's Research Institute, Parkville 3052, Victoria, Australia
| | - Kelly N Roeszler
- Murdoch Children's Research Institute, Parkville 3052, Victoria, Australia
| | - Jackie M Y How
- Department of Medicine, Austin Health, University of Melbourne, Heidelberg, Victoria 3084, Australia
| | - Ling Yeong Chia
- Department of Medicine, Austin Health, University of Melbourne, Heidelberg, Victoria 3084, Australia
| | - Kathryn North
- Murdoch Children's Research Institute, Parkville 3052, Victoria, Australia
| | - Jeffrey D Zajac
- Department of Medicine, Austin Health, University of Melbourne, Heidelberg, Victoria 3084, Australia
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Kupr B, Schnyder S, Handschin C. Role of Nuclear Receptors in Exercise-Induced Muscle Adaptations. Cold Spring Harb Perspect Med 2017; 7:a029835. [PMID: 28242783 PMCID: PMC5453380 DOI: 10.1101/cshperspect.a029835] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Skeletal muscle is not only one of the largest, but also one of the most dynamic organs. For example, plasticity elicited by endurance or resistance exercise entails complex transcriptional programs that are still poorly understood. Various signaling pathways are engaged in the contracting muscle fiber and collectively culminate in the modulation of the activity of numerous transcription factors (TFs) and coregulators. Because exercise confers many benefits for the prevention and treatment of a wide variety of pathologies, pharmacological activation of signaling pathways and TFs is an attractive avenue to elicit therapeutic effects. Members of the nuclear receptor (NR) superfamily are of particular interest owing to the presence of well-defined DNA- and ligand-binding domains. In this review, we summarize the current understanding of the involvement of NRs in muscle biology and exercise adaptation.
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Affiliation(s)
- Barbara Kupr
- Biozentrum, University of Basel, Basel 4056, Switzerland
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23
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Moloney EB, Hobo B, De Winter F, Verhaagen J. Expression of a Mutant SEMA3A Protein with Diminished Signalling Capacity Does Not Alter ALS-Related Motor Decline, or Confer Changes in NMJ Plasticity after BotoxA-Induced Paralysis of Male Gastrocnemic Muscle. PLoS One 2017; 12:e0170314. [PMID: 28103314 PMCID: PMC5245795 DOI: 10.1371/journal.pone.0170314] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2016] [Accepted: 01/02/2017] [Indexed: 12/12/2022] Open
Abstract
Terminal Schwann cells (TSCs) are specialized cells that envelop the motor nerve terminal, and play a role in the maintenance and regeneration of neuromuscular junctions (NMJs). The chemorepulsive protein semaphorin 3A (SEMA3A) is selectively up-regulated in TSCs on fast-fatigable muscle fibers following experimental denervation of the muscle (BotoxA-induced paralysis or crush injury to the sciatic nerve) or in the motor neuron disease amyotrophic lateral sclerosis (ALS). Re-expression of SEMA3A in this subset of TSCs is thought to play a role in the selective plasticity of nerve terminals as observed in ALS and following BotoxA-induced paralysis. Using a mouse model expressing a mutant SEMA3A with diminished signaling capacity, we studied the influence of SEMA3A signaling at the NMJ with two denervation paradigms; a motor neuron disease model (the G93A-hSOD1 ALS mouse line) and an injury model (BotoxA-induced paralysis). ALS mice that either expressed 1 or 2 mutant SEMA3A alleles demonstrated no difference in ALS-induced decline in motor behavior. We also investigated the effects of BotoxA-induced paralysis on the sprouting capacity of NMJs in the K108N-SEMA3A mutant mouse, and observed no change in the differential neuronal plasticity found at NMJs on fast-fatigable or slow muscle fibers due to the presence of the SEMA3A mutant protein. Our data may be explained by the residual repulsive activity of the mutant SEMA3A, or it may imply that SEMA3A alone is not a key component of the molecular signature affecting NMJ plasticity in ALS or BotoxA-induced paralysis. Interestingly, we did observe a sex difference in motor neuron sprouting behavior after BotoxA-induced paralysis in WT mice which we speculate may be an important factor in the sex dimorphic differences seen in ALS.
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Affiliation(s)
- Elizabeth B. Moloney
- Department of Regeneration of Sensorimotor Systems, Netherlands Institute for Neuroscience, an Institute of the Royal Netherlands Academy of Arts and Science, Amsterdam, The Netherlands
| | - Barbara Hobo
- Department of Regeneration of Sensorimotor Systems, Netherlands Institute for Neuroscience, an Institute of the Royal Netherlands Academy of Arts and Science, Amsterdam, The Netherlands
| | - Fred De Winter
- Department of Regeneration of Sensorimotor Systems, Netherlands Institute for Neuroscience, an Institute of the Royal Netherlands Academy of Arts and Science, Amsterdam, The Netherlands
- Department of Neurosurgery, Leiden University Medical Centre, Leiden, The Netherlands
| | - Joost Verhaagen
- Department of Regeneration of Sensorimotor Systems, Netherlands Institute for Neuroscience, an Institute of the Royal Netherlands Academy of Arts and Science, Amsterdam, The Netherlands
- Centre for Neurogenomics and Cognitive Research, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
- * E-mail:
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Liu X, Trakooljul N, Hadlich F, Muráni E, Wimmers K, Ponsuksili S. MicroRNA-mRNA regulatory networking fine-tunes the porcine muscle fiber type, muscular mitochondrial respiratory and metabolic enzyme activities. BMC Genomics 2016; 17:531. [PMID: 27485725 PMCID: PMC4970254 DOI: 10.1186/s12864-016-2850-8] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2016] [Accepted: 06/20/2016] [Indexed: 02/02/2023] Open
Abstract
Background MicroRNAs (miRNAs) are small non-coding RNAs that play critical roles in diverse biological processes via regulation of gene expression including in skeletal muscles. In the current study, miRNA expression profile was investigated in longissimus muscle biopsies of malignant hyperthermia syndrome-negative Duroc and Pietrain pigs with distinct muscle metabolic properties in order to explore the regulatory role of miRNAs related to mitochondrial respiratory activity and metabolic enzyme activity in skeletal muscle. Results A comparative analysis of the miRNA expression profile between Duroc and Pietrain pigs was performed, followed by integration with mRNA profiles based on their pairwise correlation and computational target prediction. The identified target genes were enriched in protein ubiquitination pathway, stem cell pluripotency and geranylgeranyl diphosphate biosynthesis, as well as skeletal and muscular system development. Next, we analyzed the correlation between individual miRNAs and phenotypical traits including muscle fiber type, mitochondrial respiratory activity, metabolic enzyme activity and adenosine phosphate concentrations, and constructed the regulatory miRNA-mRNA networks associated with energy metabolism. It is noteworthy that miR-25 targeting BMPR2 and IRS1, miR-363 targeting USP24, miR-28 targeting HECW2 and miR-210 targeting ATP5I, ME3, MTCH1 and CPT2 were highly associated with slow-twitch oxidative fibers, fast-twitch oxidative fibers, ADP and ATP concentration suggesting an essential role of the miRNA-mRNA regulatory networking in modulating the mitochondrial energy expenditure in the porcine muscle. In the identified miRNA-mRNA network, a tight relationship between mitochondrial and ubiquitin proteasome system at the level of gene expression was observed. It revealed a link between these two systems contributing to energy metabolism of skeletal muscle under physiological conditions. Conclusions We assembled miRNA-mRNA regulatory networks based on divergent muscle properties between different pig breeds and further with the correlation analysis of expressed genes and phenotypic measurements. These complex networks relate to muscle fiber type, metabolic enzyme activity and ATP production and may contribute to divergent muscle phenotypes by fine-tuning the expression of genes. Altogether, the results provide an insight into a regulatory role of miRNAs in muscular energy metabolisms and may have an implication on meat quality and production. Electronic supplementary material The online version of this article (doi:10.1186/s12864-016-2850-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Xuan Liu
- Leibniz Institute for Farm Animal Biology (FBN), Institute for Genome Biology, Wilhelm-Stahl-Allee 2, 18196, Dummerstorf, Germany
| | - Nares Trakooljul
- Leibniz Institute for Farm Animal Biology (FBN), Institute for Genome Biology, Wilhelm-Stahl-Allee 2, 18196, Dummerstorf, Germany
| | - Frieder Hadlich
- Leibniz Institute for Farm Animal Biology (FBN), Institute for Genome Biology, Wilhelm-Stahl-Allee 2, 18196, Dummerstorf, Germany
| | - Eduard Muráni
- Leibniz Institute for Farm Animal Biology (FBN), Institute for Genome Biology, Wilhelm-Stahl-Allee 2, 18196, Dummerstorf, Germany
| | - Klaus Wimmers
- Leibniz Institute for Farm Animal Biology (FBN), Institute for Genome Biology, Wilhelm-Stahl-Allee 2, 18196, Dummerstorf, Germany
| | - Siriluck Ponsuksili
- Leibniz Institute for Farm Animal Biology (FBN), Institute for Genome Biology, Wilhelm-Stahl-Allee 2, 18196, Dummerstorf, Germany.
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Wu J, Hadoke PWF, Takov K, Korczak A, Denvir MA, Smith LB. Influence of Androgen Receptor in Vascular Cells on Reperfusion following Hindlimb Ischaemia. PLoS One 2016; 11:e0154987. [PMID: 27159530 PMCID: PMC4861284 DOI: 10.1371/journal.pone.0154987] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2015] [Accepted: 04/23/2016] [Indexed: 01/30/2023] Open
Abstract
Aims Studies in global androgen receptor knockout (G-ARKO) and orchidectomised mice suggest that androgen accelerates reperfusion of the ischaemic hindlimb by stimulating angiogenesis. This investigation used novel, vascular cell-specific ARKO mice to address the hypothesis that the impaired hindlimb reperfusion in G-ARKO mice was due to loss of AR from cells in the vascular wall. Methods and Results Mice with selective deletion of AR (ARKO) from vascular smooth muscle cells (SM-ARKO), endothelial cells (VE-ARKO), or both (SM/VE-ARKO) were compared with wild type (WT) controls. Hindlimb ischaemia was induced in these mice by ligation and removal of the femoral artery. Post-operative reperfusion was reduced in SM-ARKO and SM/VE-ARKO mice. Immunohistochemistry indicated that this was accompanied by a reduced density of smooth muscle actin-positive vessels but no change in the density of isolectin B4-positive vessels in the gastrocnemius muscle. Deletion of AR from the endothelium (VE-ARKO) did not alter post-operative reperfusion or vessel density. In an ex vivo (aortic ring culture) model of angiogenesis, AR was not detected in vascular outgrowths and angiogenesis was not altered by vascular ARKO or by exposure to dihydrotestosterone (DHT 10−10–10-7M; 6 days). Conclusion These results suggest that loss of AR from vascular smooth muscle, but not from the endothelium, contributes to impaired reperfusion in the ischaemic hindlimb of G-ARKO. Impaired reperfusion was associated with reduced collateral formation rather than reduced angiogenesis.
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Affiliation(s)
- Junxi Wu
- MRC Centre for Reproductive Health, University of Edinburgh, The Queen's Medical Research Institute, 47 Little France Crescent, Edinburgh, EH16 4TJ, United Kingdom
- University/ BHF Centre for Cardiovascular Science, University of Edinburgh, The Queen's Medical Research Institute, 47 Little France Crescent, Edinburgh, EH16 4TJ, United Kingdom
| | - Patrick W. F. Hadoke
- University/ BHF Centre for Cardiovascular Science, University of Edinburgh, The Queen's Medical Research Institute, 47 Little France Crescent, Edinburgh, EH16 4TJ, United Kingdom
| | - Kaloyan Takov
- University/ BHF Centre for Cardiovascular Science, University of Edinburgh, The Queen's Medical Research Institute, 47 Little France Crescent, Edinburgh, EH16 4TJ, United Kingdom
| | - Agnieszka Korczak
- University/ BHF Centre for Cardiovascular Science, University of Edinburgh, The Queen's Medical Research Institute, 47 Little France Crescent, Edinburgh, EH16 4TJ, United Kingdom
| | - Martin A. Denvir
- University/ BHF Centre for Cardiovascular Science, University of Edinburgh, The Queen's Medical Research Institute, 47 Little France Crescent, Edinburgh, EH16 4TJ, United Kingdom
| | - Lee B. Smith
- MRC Centre for Reproductive Health, University of Edinburgh, The Queen's Medical Research Institute, 47 Little France Crescent, Edinburgh, EH16 4TJ, United Kingdom
- * E-mail:
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Testosterone enables growth and hypertrophy in fusion impaired myoblasts that display myotube atrophy: deciphering the role of androgen and IGF-I receptors. Biogerontology 2015; 17:619-39. [PMID: 26538344 PMCID: PMC4889645 DOI: 10.1007/s10522-015-9621-9] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2015] [Accepted: 10/19/2015] [Indexed: 11/09/2022]
Abstract
We have previously highlighted the ability of testosterone (T) to improve differentiation and myotube hypertrophy in fusion impaired myoblasts that display reduced myotube hypertrophy via multiple population doublings (PD) versus their parental controls (CON); an observation which is abrogated via PI3K/Akt inhibition (Deane et al. 2013). However, whether the most predominant molecular mechanism responsible for T induced hypertrophy occurs directly via androgen receptor or indirectly via IGF-IR/PI3K/Akt pathway is currently debated. PD and CON C2C12 muscle cells were exposed to low serum conditions in the presence or absence of T (100 nM) ± inhibitors of AR (flutamide/F, 40 μm) and IGF-IR (picropodophyllin/PPP, 150 nM) for 72 h and 7 days (early/late muscle differentiation respectively). T increased AR and Akt abundance, myogenin gene expression, and myotube hypertrophy, but not ERK1/2 activity in both CON and PD cell types. Akt activity was not increased significantly in either cell type with T. Testosterone was also unable to promote early differentiation in the presence of IGF-IR inhibitor (PPP) yet still able to promote appropriate later increases in myotube hypertrophy and AR abundance despite IGF-IR inhibition. The addition of the AR inhibitor powerfully attenuated all T induced increases in differentiation and myotube hypertrophy with corresponding reductions in AR abundance, phosphorylated Akt, ERK1/2 and gene expression of IGF-IR, myoD and myogenin with increases in myostatin mRNA in both cell types. Interestingly, despite basally reduced differentiation and myotube hypertrophy, PD cells showed larger T induced increases in AR abundance vs. CON cells, a response abrogated in the presence of AR but not IGF-IR inhibitors. Furthermore, T induced increases in Akt abundance were sustained despite the presence of IGF-IR inhibition in PD cells only. Importantly, flutamide alone reduced IGF-IR mRNA in both cell types across time points, with an observed reduction in activity of ERK and Akt, suggesting that IGF-IR was transcriptionally regulated by AR. However, where testosterone increased AR protein content there was no increases observed in IGF-IR gene expression. This suggested that sufficient AR was important to enable normal IGF-IR expression and downstream signalling, yet elevated levels of AR due to testosterone had no further effect on IGF-IR mRNA, despite testosterone increasing Akt abundance in the presence of IGF-IR inhibitor. In conclusion, testosterones ability to improve differentiation and myotube hypertrophy occurred predominately via increases in AR and Akt abundance in both CON and PD cells, with fusion impaired cells (PD) showing an increased responsiveness to T induced AR levels. Finally, T induced increases in myotube hypertrophy (but not early differentiation) occurred independently of upstream IGF-IR input, however it was apparent that normal AR function in basal conditions was required for adequate IGF-IR gene expression and downstream ERK/Akt activity.
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Haizlip KM, Harrison BC, Leinwand LA. Sex-based differences in skeletal muscle kinetics and fiber-type composition. Physiology (Bethesda) 2015; 30:30-9. [PMID: 25559153 DOI: 10.1152/physiol.00024.2014] [Citation(s) in RCA: 242] [Impact Index Per Article: 26.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Previous studies have identified over 3,000 genes that are differentially expressed in male and female skeletal muscle. Here, we review the sex-based differences in skeletal muscle fiber composition, myosin heavy chain expression, contractile function, and the regulation of these physiological differences by thyroid hormone, estrogen, and testosterone. The findings presented lay the basis for the continued work needed to fully understand the skeletal muscle differences between males and females.
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Affiliation(s)
- K M Haizlip
- Department of Molecular, Cellular, and Developmental Biology, BioFrontiers Institute, University of Colorado at Boulder, Boulder, Colorado
| | - B C Harrison
- Department of Molecular, Cellular, and Developmental Biology, BioFrontiers Institute, University of Colorado at Boulder, Boulder, Colorado
| | - L A Leinwand
- Department of Molecular, Cellular, and Developmental Biology, BioFrontiers Institute, University of Colorado at Boulder, Boulder, Colorado
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Görres A, Ponsuksili S, Wimmers K, Muráni E. Genetic variation of the porcine NR5A1 is associated with meat color. J Appl Genet 2015; 57:81-9. [DOI: 10.1007/s13353-015-0289-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2014] [Revised: 05/05/2015] [Accepted: 05/12/2015] [Indexed: 10/23/2022]
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Affiliation(s)
- Wataru Mizunoya
- Department of Bioresource Sciences, Faculty of Agriculture, Kyushu University
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Ferry A, Schuh M, Parlakian A, Mgrditchian T, Valnaud N, Joanne P, Butler-Browne G, Agbulut O, Metzger D. Myofiber androgen receptor promotes maximal mechanical overload-induced muscle hypertrophy and fiber type transition in male mice. Endocrinology 2014; 155:4739-48. [PMID: 25216388 DOI: 10.1210/en.2014-1195] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
The first aim of this study was to examine the role of myofiber androgen receptor (AR) in male mice on muscle performance gain and remodeling-induced muscle mechanical overloading (OVL) that mimics resistance training. The response of OVL in mice in which AR is selectively ablated in myofibers (AR(skm-/y)) was compared with that of wild-type (WT) mice. In addition, we determined whether the synthetic anabolic androgen nandrolone administration affects the OVL response. We found that OVL increased absolute maximal force and fatigue resistance in both mouse genotypes (P < .05). However, the absolute maximal force increased more in AR(skm-/y) mice as compared with WT mice (+88% vs +63%) (P < .05). Muscle weight increased less in response to OVL in AR(skm-/y) mice (+54%) than in WT mice (+115%) (P < .05). The fiber number per cross-section similarly increased in both mouse genotypes after OVL (P < .05). In contrast to WT mice, the diameter of the fibers expressing myosin heavy chain (MHC)-2x decreased after OVL in AR(skm-/y) mice (P < .05). The MHC-2b to MHC-2a fiber type transition in response to OVL was reduced in AR(skm-/y) mice as compared with WT mice (P < .05). Finally, nandrolone administration during OVL did not further improve absolute maximal force and fatigue resistance and markedly alter muscle remodeling in both mouse genotypes. Together, our results indicate that myofiber AR is required for a complete response to OVL and that exogenous androgens do not increase muscle performance during intensive remodeling in male mice.
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Affiliation(s)
- Arnaud Ferry
- Université Pierre et Marie Curie Université Paris 06 (A.F., T.M., N.V., G.B.-B.), Sorbonne Universités, Inserm Unité 974, Centre National de la Recherche Scientifique Unité Mixte de Recherche 7215, Institut de Myologie, F-75013 Paris, France; Université Paris Descartes (A.F.), Sorbonne Paris Cité, F-75006 Paris, France; Institut de Génétique et de Biologie Moléculaire et Cellulaire (M.S., D.M.), Centre National de la Recherche Scientifique Unité Mixte de Recherche 7104, Inserm Unité 964, Université de Strasbourg, Illkirch 67404, France; and Université Pierre et Marie Curie Université Paris 06 (A.P., T.M., P.J., O.A.), Sorbonne Universités, Unité Mixte de Recherche Centre National de la Recherche Scientifique 8256, Biological Adaptation and Ageing, F-75005 Paris, France
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Rana K, Davey RA, Zajac JD. Human androgen deficiency: insights gained from androgen receptor knockout mouse models. Asian J Androl 2014; 16:169-77. [PMID: 24480924 PMCID: PMC3955325 DOI: 10.4103/1008-682x.122590] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The mechanism of androgen action is complex. Recently, significant advances have been made into our understanding of how androgens act via the androgen receptor (AR) through the use of genetically modified mouse models. A number of global and tissue-specific AR knockout (ARKO) models have been generated using the Cre-loxP system which allows tissue- and/or cell-specific deletion. These ARKO models have examined a number of sites of androgen action including the cardiovascular system, the immune and hemopoetic system, bone, muscle, adipose tissue, the prostate and the brain. This review focuses on the insights that have been gained into human androgen deficiency through the use of ARKO mouse models at each of these sites of action, and highlights the strengths and limitations of these Cre-loxP mouse models that should be considered to ensure accurate interpretation of the phenotype.
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Affiliation(s)
| | | | - Jeffrey D Zajac
- Department of Medicine, Austin Health, University of Melbourne, Heidelberg, Victoria, Australia
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Chang C, Yeh S, Lee SO, Chang TM. Androgen receptor (AR) pathophysiological roles in androgen-related diseases in skin, bone/muscle, metabolic syndrome and neuron/immune systems: lessons learned from mice lacking AR in specific cells. NUCLEAR RECEPTOR SIGNALING 2013; 11:e001. [PMID: 24653668 PMCID: PMC3960937 DOI: 10.1621/nrs.11001] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/07/2013] [Accepted: 05/28/2013] [Indexed: 12/19/2022]
Abstract
The androgen receptor (AR) is expressed ubiquitously and plays a variety of roles in a vast number of physiological and pathophysiological processes. Recent studies of AR knockout (ARKO) mouse models, particularly the cell type- or tissue-specific ARKO models, have uncovered many AR cell type- or tissue-specific pathophysiological roles in mice, which otherwise would not be delineated from conventional castration and androgen insensitivity syndrome studies. Thus, the AR in various specific cell types plays pivotal roles in production and maturation of immune cells, bone mineralization, and muscle growth. In metabolism, the ARs in brain, particularly in the hypothalamus, and the liver appear to participate in regulation of insulin sensitivity and glucose homeostasis. The AR also plays key roles in cutaneous wound healing and cardiovascular diseases, including atherosclerosis and abdominal aortic aneurysm. This article will discuss the results obtained from the total, cell type-, or tissue-specific ARKO models. The understanding of AR cell type- or tissue-specific physiological and pathophysiological roles using these in
vivo mouse models will provide useful information in uncovering AR roles in humans and eventually help us to develop better therapies via targeting the AR or its downstream signaling molecules to combat androgen/AR-related diseases.
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Affiliation(s)
- Chawnshang Chang
- George Whipple Lab for Cancer Research, Departments of Pathology, Urology, Radiation Oncology, and the Wilmot Cancer Center, University of Rochester Medical Center, Rochester, New York, USA (CC, SY, SOL, T-MC) and Sex Hormone Research Center, China Medical University/Hospital, Taichung, Taiwan (CC)
| | - Shuyuan Yeh
- George Whipple Lab for Cancer Research, Departments of Pathology, Urology, Radiation Oncology, and the Wilmot Cancer Center, University of Rochester Medical Center, Rochester, New York, USA (CC, SY, SOL, T-MC) and Sex Hormone Research Center, China Medical University/Hospital, Taichung, Taiwan (CC)
| | - Soo Ok Lee
- George Whipple Lab for Cancer Research, Departments of Pathology, Urology, Radiation Oncology, and the Wilmot Cancer Center, University of Rochester Medical Center, Rochester, New York, USA (CC, SY, SOL, T-MC) and Sex Hormone Research Center, China Medical University/Hospital, Taichung, Taiwan (CC)
| | - Ta-Min Chang
- George Whipple Lab for Cancer Research, Departments of Pathology, Urology, Radiation Oncology, and the Wilmot Cancer Center, University of Rochester Medical Center, Rochester, New York, USA (CC, SY, SOL, T-MC) and Sex Hormone Research Center, China Medical University/Hospital, Taichung, Taiwan (CC)
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Nasipak B, Kelley DB. Developing laryngeal muscle of Xenopus laevis as a model system: androgen-driven myogenesis controls fiber type transformation. Dev Neurobiol 2012; 72:664-75. [PMID: 21954146 DOI: 10.1002/dneu.20983] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The developmental programs that contribute to myogenic stem cell proliferation and muscle fiber differentiation control fiber numbers and twitch type. In this study, we describe the use of an experimental model system-androgen-regulated laryngeal muscle of juvenile clawed frogs, Xenopus laevis-to examine the contribution of proliferation by specific populations of myogenic stem cells to expression of the larynx-specific myosin heavy chain isoform, LM. Androgen treatment of juveniles (Stage PM0) resulted in upregulation of an early (Myf-5) and a late (myogenin) myogenic regulatory factor; the time course of LM upregulation tracked that of myogenin. Myogenic stem cells stimulated to proliferate by androgen include a population that expresses Pax-7, a marker for the satellite cell myogenic stem cell population. Since androgen can switch muscle fiber types from fast to slow even in denervated larynges, we developed an ex vivo culture system to explore the relation between proliferation and LM expression. Cultured whole larynges maintain sensitivity to androgen, increasing in size and LM expression. Blockade of cell proliferation with cis-platin prevents the switch from slow to fast twitch muscle fibers as assayed by ATPase activity. Blockade of cell proliferation in vivo also resulted in inhibition of LM expression. Thus, both in vivo and ex vivo, inhibition of myogenic stem cell proliferation blocks androgen-induced LM expression and fiber type switching in juveniles.
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Affiliation(s)
- Brian Nasipak
- Department of Cell Biology, UMass Medical School, Worchester, MA 01655, USA
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Tsai MY, Shyr CR, Kang HY, Chang YC, Weng PL, Wang SY, Huang KE, Chang C. The reduced trabecular bone mass of adult ARKO male mice results from the decreased osteogenic differentiation of bone marrow stroma cells. Biochem Biophys Res Commun 2011; 411:477-82. [PMID: 21723262 DOI: 10.1016/j.bbrc.2011.06.113] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2011] [Accepted: 06/15/2011] [Indexed: 10/18/2022]
Abstract
Male mice with androgen receptor knock-out (ARKO) show significant bone loss at a young age. However, the lasting effect of AR inactivation on bone in aging male mice remains unclear. We designed this study to evaluate the effect of AR on bone quality in aging male mice and to find the possible causes of AR inactivation contributing to the bone loss. The mice were grouped according to their ages and AR status and their trabecular bones were examined by micro-CT analysis at 6, 12, 18, and 30 weeks old. We found that bone mass consistently decreased and the bone microarchitectures continuously deteriorated in male ARKO mice at designated time points. To determine the cause of the bone loss in ARKO mice, we further examined the role of AR in bone cell fate decision and differentiation and we conducted experiments on bone marrow stromal cells (BMSC) obtained from wild type (WT) and AR knockout (KO) mice. We found that ARKO mice had higher numbers of colony formation unit-fibroblast (CFU-F), and CD44 and CD34 positive cells in bone marrow than WT mice. Our Q-RT-PCR results showed lower expression of genes linked to osteogenesis in BMSCs isolated from ARKO mice. In conclusion, AR nullification disrupted bone microarchitecture and caused trabecular bone mass loss in male ARKO mice. And the fate of BMSCs was impacted by the loss of AR. Therefore, these findings suggest that AR may accelerate the use of progenitor cells and direct them into osteogenic differentiation to affect bone metabolism.
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Affiliation(s)
- Meng-Yin Tsai
- Center for Menopause and Reproductive Medicine Research, Department of Obstetrics and Gynecology, Kaohsiung Chang-Gung Memorial Hospital, Kaohsiung, Taiwan
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De Jager N, Hudson NJ, Reverter A, Wang YH, Nagaraj SH, Cafe LM, Greenwood PL, Barnard RT, Kongsuwan KP, Dalrymple BP. Chronic exposure to anabolic steroids induces the muscle expression of oxytocin and a more than fiftyfold increase in circulating oxytocin in cattle. Physiol Genomics 2011; 43:467-78. [DOI: 10.1152/physiolgenomics.00226.2010] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Molecular mechanisms in skeletal muscle associated with anabolic steroid treatment of cattle are unclear and we aimed to characterize transcriptional changes. Cattle were chronically exposed (68 ± 20 days) to a steroid hormone implant containing 200 mg trenbolone acetate and 20 mg estradiol (Revalor-H). Biopsy samples from 48 cattle (half treated) from longissimus dorsi (LD) muscle under local anesthesia were collected. Gene expression levels were profiled by microarray, covering 16,944 unique bovine genes: 121 genes were differentially expressed (DE) due to the implant (99.99% posterior probability of not being false positives). Among DE genes, a decrease in expression of a number of fat metabolism-associated genes, likely reflecting the lipid storage activity of intramuscular adipocytes, was observed. The expression of IGF1 and genes related to the extracellular matrix, slow twitch fibers, and cell cycle (including SOX8, a satellite cell marker) was increased in the treated muscle. Unexpectedly, a very large 21- (microarray) to 97 (real time quantitative PCR)-fold higher expression of the mRNA encoding the neuropeptide hormone oxytocin was observed in treated muscle. We also observed an ∼50-fold higher level of circulating oxytocin in the plasma of treated animals at the time of biopsy. Using a coexpression network strategy OXTR was identified as more likely than IGF1R to be a major mediator of the muscle response to Revalor-H. A re-investigation of in vivo cattle LD muscle samples during early to mid-fetal development identified a >128-fold increased expression of OXT, coincident with myofiber differentiation and fusion. We propose that oxytocin may be involved in mediating the anabolic effects of Revalor-H treatment.
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Affiliation(s)
- Nadia De Jager
- Australian Cooperative Research Centre for Beef Genetic Technologies, University of New England, Armidale, New South Wales
- Commonwealth Scientific and Industrial Research Organisation Livestock Industries, Queensland Bioscience Precinct
- School of Chemistry and Molecular Biosciences, Faculty of Science and
| | - Nicholas J. Hudson
- Australian Cooperative Research Centre for Beef Genetic Technologies, University of New England, Armidale, New South Wales
- Commonwealth Scientific and Industrial Research Organisation Livestock Industries, Queensland Bioscience Precinct
| | - Antonio Reverter
- Australian Cooperative Research Centre for Beef Genetic Technologies, University of New England, Armidale, New South Wales
- Commonwealth Scientific and Industrial Research Organisation Livestock Industries, Queensland Bioscience Precinct
| | - Yong-Hong Wang
- Australian Cooperative Research Centre for Beef Genetic Technologies, University of New England, Armidale, New South Wales
- Commonwealth Scientific and Industrial Research Organisation Livestock Industries, Queensland Bioscience Precinct
| | - Shivashankar H. Nagaraj
- Commonwealth Scientific and Industrial Research Organisation Livestock Industries, Queensland Bioscience Precinct
| | - Linda M. Cafe
- Australian Cooperative Research Centre for Beef Genetic Technologies, University of New England, Armidale, New South Wales
- Industry & Investment NSW, Beef Industry Centre, University of New England, Armidale, New South Wales, Australia
| | - Paul L. Greenwood
- Australian Cooperative Research Centre for Beef Genetic Technologies, University of New England, Armidale, New South Wales
- Industry & Investment NSW, Beef Industry Centre, University of New England, Armidale, New South Wales, Australia
| | - Ross T. Barnard
- School of Molecular and Microbial Sciences, Centre for Infectious Disease Research, University of Queensland, St. Lucia, Queensland; and
| | - Kritaya P. Kongsuwan
- Commonwealth Scientific and Industrial Research Organisation Livestock Industries, Queensland Bioscience Precinct
| | - Brian P. Dalrymple
- Australian Cooperative Research Centre for Beef Genetic Technologies, University of New England, Armidale, New South Wales
- Commonwealth Scientific and Industrial Research Organisation Livestock Industries, Queensland Bioscience Precinct
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Zhao JX, Hu J, Zhu MJ, Du M. Trenbolone enhances myogenic differentiation by enhancing β-catenin signaling in muscle-derived stem cells of cattle. Domest Anim Endocrinol 2011; 40:222-9. [PMID: 21402455 PMCID: PMC4100702 DOI: 10.1016/j.domaniend.2011.01.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/17/2010] [Revised: 01/24/2011] [Accepted: 01/26/2011] [Indexed: 01/18/2023]
Abstract
Testosterone is a key hormone regulating animal growth and development, which promotes skeletal muscle growth and inhibits fat deposition; however, the underlying mechanisms remain poorly defined. Because canonical Wingless and Int/β-catenin signaling promotes myogenesis, we hypothesized that testosterone regulates myogenesis through enhancing the β-catenin signaling pathway and the expression of its targeted genes. Muscle-derived stem cells were prepared from the skeletal muscle of fetal calf at day 180 of gestation and treated with or without trenbolone (10 nM), a synthetic analog of testosterone, in a myogenic medium. Trenbolone treatment increased the protein levels of MyoD and myosin heavy chain, as well as the androgen receptor content. The myogenic effect of trenbolone was blocked by cyproterone acetate, a specific inhibitor of androgen receptor, showing that the myogenic effect of trenbolone was mediated by the androgen receptor. Immunoprecipitation showed that androgen receptor and β-catenin formed a complex, which was increased by trenbolone treatment. Trenbolone activated adenosine monophosphate-activated protein kinase, which might phosphorylate β-catenin at Ser552, stabilizing β-catenin. Indeed, both cytoplasmic and nuclear β-catenin levels were increased after trenbolone treatment. As a result, β-catenin-mediated transcriptional activity was enhanced by trenbolone treatment. In conclusion, these data provide evidence that testosterone increases cellular β-catenin content which promotes the expression of β-catenin-targeted genes and myogenesis in the muscle-derived stem cells of cattle.
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Affiliation(s)
- J-X Zhao
- Department of Animal Science, University of Wyoming, 1000 E. University Avenue, Laramie, WY 82071, USA
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Ophoff J, Van Proeyen K, Callewaert F, De Gendt K, De Bock K, Vanden Bosch A, Verhoeven G, Hespel P, Vanderschueren D. Androgen signaling in myocytes contributes to the maintenance of muscle mass and fiber type regulation but not to muscle strength or fatigue. Endocrinology 2009; 150:3558-66. [PMID: 19264874 DOI: 10.1210/en.2008-1509] [Citation(s) in RCA: 93] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Muscle frailty is considered a major cause of disability in the elderly and chronically ill. However, the exact role of androgen receptor (AR) signaling in muscle remains unclear. Therefore, a postmitotic myocyte-specific AR knockout (mARKO) mouse model was created and investigated together with a mouse model with ubiquitous AR deletion. Muscles from mARKO mice displayed a marked reduction in AR protein (60-88%). Interestingly, body weights and lean body mass were lower in mARKO vs. control mice (-8%). The weight of the highly androgen-sensitive musculus levator ani was significantly reduced (-46%), whereas the weights of other peripheral skeletal muscles were not or only slightly reduced. mARKO mice had lower intra-abdominal fat but did not demonstrate a cortical or trabecular bone phenotype, indicating that selective ablation of the AR in myocytes affected male body composition but not skeletal homeostasis. Furthermore, muscle contractile performance in mARKO mice did not differ from their controls. Myocyte-specific AR ablation resulted in a conversion of fast toward slow fibers, without affecting muscle strength or fatigue. Similar results were obtained in ubiquitous AR deletion, showing lower body weight, whereas some but not all muscle weights were reduced. The percent slow fibers was increased, but no changes in muscle strength or fatigue could be detected. Together, our findings show that myocyte AR signaling contributes to the maintenance of muscle mass and fiber type regulation but not to muscle strength or fatigue. The levator ani weight remains the most sensitive and specific marker of AR-mediated anabolic action on muscle.
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MESH Headings
- Absorptiometry, Photon
- Animals
- Blotting, Western
- Creatine Kinase, MM Form/genetics
- Female
- Glycogen/metabolism
- Immunohistochemistry
- Intra-Abdominal Fat/metabolism
- Male
- Mice
- Mice, Knockout
- Mice, Mutant Strains
- Microscopy, Fluorescence
- Muscle Cells/metabolism
- Muscle Fatigue/genetics
- Muscle Fatigue/physiology
- Muscle Fibers, Skeletal/metabolism
- Muscle Strength/genetics
- Muscle Strength/physiology
- Muscles/metabolism
- Muscles/physiology
- Receptors, Androgen/genetics
- Receptors, Androgen/metabolism
- Receptors, Androgen/physiology
- Satellite Cells, Skeletal Muscle/metabolism
- Succinate Dehydrogenase/metabolism
- X-Ray Microtomography
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Affiliation(s)
- Jill Ophoff
- Department ofExperimental Medicine, Laboratory for Experimental Medicine and Endocrinology, Katholieke Universiteit Leuven, B-3000 Leuven, Belgium
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38
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Wannenes F, Caprio M, Gatta L, Fabbri A, Bonini S, Moretti C. Androgen receptor expression during C2C12 skeletal muscle cell line differentiation. Mol Cell Endocrinol 2008; 292:11-9. [PMID: 18588941 DOI: 10.1016/j.mce.2008.05.018] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/05/2008] [Revised: 05/05/2008] [Accepted: 05/19/2008] [Indexed: 11/23/2022]
Abstract
The Androgen Receptor (AR) pathway is involved in the development of skeletal muscle but the molecular basis of androgen-related myogenic enhancement is still unclear. We have investigated AR expression and localization during myoblasts-myotubes differentiation in skeletal muscle cell line C2C12. AR expression increases during proliferation and commitment phase and its levels remain elevated in myotubes. In proliferating and committed cells in the absence of testosterone, AR protein localizes in the nuclei whereas it is almost totally localized in the cytoplasm in myotubes. Low testosterone doses shift the receptor in the nuclei without increasing the amount of total protein. High doses of T induce a significant increase of AR expression during proliferation and differentiation. Little information is available on AR targets that drive the myogenic process. In our study, testosterone induces myogenin, myosin heavy chains (MyHC) and GRIP-1 expression, suggesting that AR and its coregulatory proteins are pivotal factors in skeletal muscle differentiation.
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Affiliation(s)
- Francesca Wannenes
- Department of Sciences of Human Movement and Sport, IUSM-University of Sport and Movement Sciences, Rome, Italy
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39
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Ting HJ, Chang C. Actin associated proteins function as androgen receptor coregulators: an implication of androgen receptor's roles in skeletal muscle. J Steroid Biochem Mol Biol 2008; 111:157-63. [PMID: 18590822 DOI: 10.1016/j.jsbmb.2008.06.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/14/2007] [Accepted: 06/05/2008] [Indexed: 11/28/2022]
Abstract
This review of androgen receptor (AR) coregulators, which also function as actin-binding proteins, intends to establish the connection between actin cytoskeletal components and androgen signaling, especially in skeletal muscle. In cellular and animal models, androgen activated AR modulates myoblasts proliferation, promotes sexual dimorphic muscle development, and alters muscle fiber type. In the clinical setting, administration of anabolic androgens can decrease cachexia and speed wound healing. During myogenesis and regeneration of skeletal muscle in embryo and adult, the membrane of myoblasts fuse and the actin cytoskeleton is rearranged to form an alignment with myosin to form myotubes then ultimately the myofibrils. Contraction of skeletal muscle promotes the growth of myocytes by coordinating signals from the neuromuscular junction to intra-myofibrils through costameres, the functional structure comprised of signal proteins closely associated with actin filaments and involved in muscular dystrophy. Therefore, the discovery of actin-binding proteins functioning as AR coregulators implies that androgen signaling is tightly regulated during the process of the development and regeneration of skeletal muscle. The search for selective androgen receptor modulators (SARM) that act precisely in skeletal muscle instead of other tissues could target the engineering of a SARM-AR complex that selectively recruits these coregulators.
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Affiliation(s)
- Huei-Ju Ting
- Department of Pathology and Urology, The Cancer Center, University of Rochester Medical Center, Rochester, NY 14642, USA
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40
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Harada N, Ohmori Y, Yamaji R, Higashimura Y, Okamoto K, Isohashi F, Nakano Y, Inui H. ARA24/Ran enhances the androgen-dependent NH2- and COOH-terminal interaction of the androgen receptor. Biochem Biophys Res Commun 2008; 373:373-7. [DOI: 10.1016/j.bbrc.2008.06.024] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2008] [Accepted: 06/10/2008] [Indexed: 11/15/2022]
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41
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MacLean HE, Chiu WSM, Notini AJ, Axell AM, Davey RA, McManus JF, Ma C, Plant DR, Lynch GS, Zajac JD. Impaired skeletal muscle development and function in male, but not female, genomic
androgen receptor
knockout mice. FASEB J 2008; 22:2676-89. [DOI: 10.1096/fj.08-105726] [Citation(s) in RCA: 141] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Affiliation(s)
- Helen E. MacLean
- Department of MedicineUniversity of Melbourne, Austin HealthHeidelbergVictoriaAustralia
| | - W. S. Maria Chiu
- Department of MedicineUniversity of Melbourne, Austin HealthHeidelbergVictoriaAustralia
| | - Amanda J. Notini
- Department of MedicineUniversity of Melbourne, Austin HealthHeidelbergVictoriaAustralia
| | - Anna-Maree Axell
- Department of MedicineUniversity of Melbourne, Austin HealthHeidelbergVictoriaAustralia
| | - Rachel A. Davey
- Department of MedicineUniversity of Melbourne, Austin HealthHeidelbergVictoriaAustralia
| | - Julie F. McManus
- Department of MedicineUniversity of Melbourne, Austin HealthHeidelbergVictoriaAustralia
| | - Cathy Ma
- Department of MedicineUniversity of Melbourne, Austin HealthHeidelbergVictoriaAustralia
| | - David R. Plant
- Department of PhysiologyUniversity of MelbourneMelbourneVictoriaAustralia
| | - Gordon S. Lynch
- Department of PhysiologyUniversity of MelbourneMelbourneVictoriaAustralia
| | - Jeffrey D. Zajac
- Department of MedicineUniversity of Melbourne, Austin HealthHeidelbergVictoriaAustralia
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42
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Dayton WR, White ME. Cellular and molecular regulation of muscle growth and development in meat animals1,2. J Anim Sci 2008; 86:E217-25. [PMID: 17709769 DOI: 10.2527/jas.2007-0456] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Although in vivo and in vitro studies have established that anabolic steroids, transforming growth factor-beta (TGF-beta), and myostatin affect muscle growth in meat-producing animals, their mechanisms of action are not completely understood. Anabolic steroids have been widely used as growth promoters in feedlot cattle for over 50 yr. A growing body of evidence suggests that increased muscle levels of IGF-I and increased muscle satellite cell numbers play a role in anabolic steroid enhanced muscle growth. In contrast to anabolic steroids, the members of the TGF-beta-myostatin family suppress muscle growth in vivo and suppress both proliferation and differentiation of cultured myogenic cells. Recent evidence suggests that IGFBP-3 and IGFBP-5 play a role in mediating the proliferation-suppressing actions of both TGF-beta and myostatin on cultured myogenic cells. Consequently, this review will focus on the roles of IGF-I and IGFBP in the cellular and molecular mechanisms of action of anabolic steroids and TGF-beta and myostatin, respectively.
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Affiliation(s)
- W R Dayton
- Department of Animal Science, University of Minnesota, St. Paul, MN 55108, USA.
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43
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Burnes LA, Kolker SJ, Danielson JF, Walder RY, Sluka KA. Enhanced muscle fatigue occurs in male but not female ASIC3-/- mice. Am J Physiol Regul Integr Comp Physiol 2008; 294:R1347-55. [PMID: 18305024 DOI: 10.1152/ajpregu.00687.2007] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Muscle fatigue is associated with a number of clinical diseases, including chronic pain conditions. Decreases in extracellular pH activates acid-sensing ion channel 3 (ASIC3), depolarizes muscle, protects against fatigue, and produces pain. We examined whether ASIC3-/- mice were more fatigable than ASIC3+/+ mice in a task-dependent manner. We developed two exercise protocols to measure exercise-induced muscle fatigue: (fatigue task 1, three 1-h runs; fatigue task 2, three 30-min runs). In fatigue task 1, male ASIC3+/+ mice muscle showed less fatigue than male ASIC3-/- mice and female ASIC3+/+ mice. No differences in fatigue were observed in fatigue task 2. We then tested whether the development of muscle fatigue was dependent on sex and modulated by testosterone. Female ASIC3+/+ mice that were ovariectomized and administered testosterone developed less muscle fatigue than female ASIC3+/+ mice and behaved similarly to male ASIC3+/+ mice. However, testosterone was unable to rescue the muscle fatigue responses in ovariectomized ASIC3-/- mice. Plasma levels of testosterone from male ASIC3-/- mice were significantly lower than in male ASIC3+/+ mice and were similar to female ASIC3+/+ mice. Muscle fiber types, measured by counting ATPase-stained whole muscle sections, were similar in calf muscles from male and female ASIC3+/+ mice. These data suggest that both ASIC3 and testosterone are necessary to protect against muscle fatigue in a task-dependent manner. Also, differences in expression of ASIC3 and the development of exercise-induced fatigue could explain the female predominance in clinical syndromes of pain that include muscle fatigue.
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Affiliation(s)
- Lynn A Burnes
- Graduate Program in Physical Therapy and Rehabilitation Science, Pain Research Program, Neuroscience Graduate Program, University of Iowa, Iowa City, IA 52242, USA
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44
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Cellular and molecular mechanisms underlying age-related skeletal muscle wasting and weakness. Biogerontology 2008; 9:213-28. [PMID: 18299960 DOI: 10.1007/s10522-008-9131-0] [Citation(s) in RCA: 280] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2007] [Accepted: 02/06/2008] [Indexed: 01/02/2023]
Abstract
Some of the most serious consequences of ageing are its effects on skeletal muscle. The term 'sarcopenia' describes the slow but progressive loss of muscle mass with advancing age and is characterised by a deterioration of muscle quantity and quality leading to a gradual slowing of movement and a decline in strength. The loss of muscle mass and strength is thought to be attributed to the progressive atrophy and loss of individual muscle fibres associated with the loss of motor units, and a concomitant reduction in muscle 'quality' due to the infiltration of fat and other non-contractile material. These age-related changes in skeletal muscle can be largely attributed to the complex interaction of factors affecting neuromuscular transmission, muscle architecture, fibre composition, excitation-contraction coupling, and metabolism. Given the magnitude of the growing public health problems associated with sarcopenia, there is considerable interest in the development and evaluation of therapeutic strategies to attenuate, prevent, or ultimately reverse age-related muscle wasting and weakness. The aim is to review our current understanding of some of the cellular and molecular mechanisms responsible for age-related changes in skeletal muscle.
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45
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Montano M, Flanagan JN, Jiang L, Sebastiani P, Rarick M, LeBrasseur NK, Morris CA, Jasuja R, Bhasin S. Transcriptional profiling of testosterone-regulated genes in the skeletal muscle of human immunodeficiency virus-infected men experiencing weight loss. J Clin Endocrinol Metab 2007; 92:2793-802. [PMID: 17440010 DOI: 10.1210/jc.2006-2722] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
CONTEXT HIV-associated wasting and weight loss remain clinically significant concerns even in the era of potent antiretroviral therapy. Although androgen treatment increases muscle mass, the cell-intrinsic mechanisms engaged remain poorly understood. OBJECTIVE This study was an unbiased approach to identify expression profiles associated with testosterone treatment using genome-wide microarray analysis of skeletal muscle biopsies. DESIGN, SETTING, AND PARTICIPANTS Forty-four HIV-positive men with weight loss were randomized to receive either 300 mg testosterone enanthate or placebo injections im weekly for 16 wk. Muscle biopsies were obtained at baseline and on treatment d 14. A subset of specimens was chosen for microarray analysis, with changes in selected genes confirmed by real-time PCR, Western blot analysis, and in vitro culture of muscle precursor cells. RESULTS Significantly greater gains in body mass (+2.05 and -1.07 kg, respectively; P = 0.003) and lean body mass by dual-energy x-ray absorptiometry (2.93 vs. 0.35 kg, respectively; P = 0.003) were observed in subjects treated with testosterone compared with placebo. Microarray analysis revealed up-regulation in genes involved in myogenesis and muscle protein synthesis, immune regulation, metabolic pathways, and chromatin remodeling. Representative genes were confirmed by real-time PCR and protein expression studies. In an independent analysis, gene networks that differentiate healthy young men from older men with sarcopenia had substantial overlap with those activated by testosterone treatment. CONCLUSIONS These data provide new insights into the mechanisms of androgen action and have implications for both development of muscle biomarkers and anabolic therapies for wasting and sarcopenia.
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Affiliation(s)
- Monty Montano
- Section of Infectious Diseases, Center for HIV-1/AIDS Care and Research, School of Public Health, Boston University, Boston, Massachusetts 02118, USA.
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Lynch GS, Schertzer JD, Ryall JG. Therapeutic approaches for muscle wasting disorders. Pharmacol Ther 2007; 113:461-87. [PMID: 17258813 DOI: 10.1016/j.pharmthera.2006.11.004] [Citation(s) in RCA: 100] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2006] [Revised: 11/10/2006] [Accepted: 11/10/2006] [Indexed: 12/12/2022]
Abstract
Muscle wasting and weakness are common in many disease states and conditions including aging, cancer cachexia, sepsis, denervation, disuse, inactivity, burns, HIV-acquired immunodeficiency syndrome (AIDS), chronic kidney or heart failure, unloading/microgravity, and muscular dystrophies. Although the maintenance of muscle mass is generally regarded as a simple balance between protein synthesis and protein degradation, these mechanisms are not strictly independent, but in fact they are coordinated by a number of different and sometimes complementary signaling pathways. Clearer details are now emerging about these different molecular pathways and the extent to which these pathways contribute to the etiology of various muscle wasting disorders. Therapeutic strategies for attenuating muscle wasting and improving muscle function vary in efficacy. Exercise and nutritional interventions have merit for slowing the rate of muscle atrophy in some muscle wasting conditions, but in most cases they cannot halt or reverse the wasting process. Hormonal and/or other drug strategies that can target key steps in the molecular pathways that regulate protein synthesis and protein degradation are needed. This review describes the signaling pathways that maintain muscle mass and provides an overview of some of the major conditions where muscle wasting and weakness are indicated. The review provides details on some therapeutic strategies that could potentially attenuate muscle atrophy, promote muscle growth, and ultimately improve muscle function. The emphasis is on therapies that can increase muscle mass and improve functional outcomes that will ultimately lead to improvement in the quality of life for affected patients.
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Affiliation(s)
- Gordon S Lynch
- Basic and Clinical Myology Laboratory, Department of Physiology, The University of Melbourne, Victoria 3010, Australia.
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Mulholland DJ, Dedhar S, Wu H, Nelson CC. PTEN and GSK3beta: key regulators of progression to androgen-independent prostate cancer. Oncogene 2006; 25:329-37. [PMID: 16421604 DOI: 10.1038/sj.onc.1209020] [Citation(s) in RCA: 165] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Prostate cancer (PrCa) is characterized by progression from an androgen-dependent phenotype to one that is inevitably androgen independent (AI) and lethal. Recent evidence strongly suggests that the phosphatidylinositol-3-kinase/Akt (PI3K/Akt) and androgen receptor (AR) signalling pathways provide prostatic epithelium with the necessary signalling events to escape the apoptotic response associated with androgen withdrawal therapy. Silencing of phosphatase and tensin homologue deleted on chromosome 10 (PTEN) and glycogen synthase kinase beta (GSK3beta) are frequently associated with advanced PrCa systems and likely serve critical roles in promoting AR and PI3K/Akt gain-of-function. That PTEN negatively regulates AR and is sufficient to promote metastatic PrCa in murine models strongly implies its role as a gatekeeper of progressive PrCa. In human PrCa, PTEN loss is correlated with substantial increases in Akt(Ser473) and integrin-linked kinase expression, both of which promote Ser(9) phospho-inhibition of GSK3beta and inactivation of apoptotic factors. Sufficient evidence also suggests that GSK3beta is not only a critical regulator of proproliferative signalling but also a promiscuous one as PI3K/Akt pools of GSK3beta are, at least in part, functionally interchangeable with those of the Wnt/beta-catenin pathway. Thus, GSK3beta may serve not only as a mediator of PI3K/Akt activation but may also regulate the potent transactivation and proproliferative effects that Wnt3a and beta-catenin confer upon AR. These data suggest that prostate-specific activation of GSK3beta may serve as a viable pharmacological option. Thus, in this review, we emphasize that temporal changes in GSK3beta and PTEN expression during progression to AI PrCa are important factors when considering the potential for therapies targeting the oncogenic contributions of PI3K/Akt and AR signalling pathways.
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Affiliation(s)
- D J Mulholland
- Department of Molecular and Medical Pharmacology, UCLA School of Medicine, Los Angeles, CA 90095, USA.
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