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Russell PK, Mangiafico S, Fam BC, Clarke MV, Marin ES, Andrikopoulos S, Wiren KM, Zajac JD, Davey RA. The androgen receptor in bone marrow progenitor cells negatively regulates fat mass. J Endocrinol 2018; 237:15-27. [PMID: 29386237 DOI: 10.1530/joe-17-0656] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Accepted: 01/29/2018] [Indexed: 12/14/2022]
Abstract
It is well established that testosterone negatively regulates fat mass in humans and mice; however, the mechanism by which testosterone exerts these effects is poorly understood. We and others have shown that deletion of the androgen receptor (AR) in male mice results in a phenotype that mimics the three key clinical aspects of hypogonadism in human males; increased fat mass and decreased bone and muscle mass. We now show that replacement of the Ar gene specifically in mesenchymal progenitor cells (PCs) residing in the bone marrow of Global-ARKO mice, in the absence of the AR in all other tissues (PC-AR Gene Replacements), completely attenuates their increased fat accumulation. Inguinal subcutaneous white adipose tissue and intra-abdominal retroperitoneal visceral adipose tissue depots in PC-AR Gene Replacement mice were 50-80% lower than wild-type (WT) and 75-90% lower than Global-ARKO controls at 12 weeks of age. The marked decrease in subcutaneous and visceral fat mass in PC-AR Gene Replacements was associated with an increase in the number of small adipocytes and a healthier metabolic profile compared to WT controls, characterised by normal serum leptin and elevated serum adiponectin levels. Euglycaemic/hyperinsulinaemic clamp studies reveal that the PC-AR Gene Replacement mice have improved whole-body insulin sensitivity with higher glucose infusion rates compared to WT mice and increased glucose uptake into subcutaneous and intra-abdominal fat. In conclusion, these data provide the first evidence for an action of androgens via the AR in mesenchymal bone marrow PCs to negatively regulate fat mass and improve metabolic function.
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Affiliation(s)
- Patricia K Russell
- Department of MedicineAustin Health, University of Melbourne, Heidelberg, Victoria, Australia
| | - Salvatore Mangiafico
- Department of MedicineAustin Health, University of Melbourne, Heidelberg, Victoria, Australia
| | - Barbara C Fam
- Department of MedicineAustin Health, University of Melbourne, Heidelberg, Victoria, Australia
| | - Michele V Clarke
- Department of MedicineAustin Health, University of Melbourne, Heidelberg, Victoria, Australia
| | - Evelyn S Marin
- Department of MedicineAustin Health, University of Melbourne, Heidelberg, Victoria, Australia
| | - Sofianos Andrikopoulos
- Department of MedicineAustin Health, University of Melbourne, Heidelberg, Victoria, Australia
| | - Kristine M Wiren
- Research ServiceVeterans Affairs Medical Center, Portland, Oregon, USA
- Departments of Medicine and Behavioral NeuroscienceOregon Health & Science University, Portland, Oregon, USA
| | - Jeffrey D Zajac
- Department of MedicineAustin Health, University of Melbourne, Heidelberg, Victoria, Australia
| | - Rachel A Davey
- Department of MedicineAustin Health, University of Melbourne, Heidelberg, Victoria, Australia
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52
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Zhou T, Hu ZY, Zhang HP, Zhao K, Zhang Y, Li Y, Wei JJ, Yuan HF. Effects of Testosterone Supplementation on Body Composition in HIV Patients: A Meta-analysis of Double-blinded Randomized Controlled Trials. Curr Med Sci 2018; 38:191-198. [PMID: 30074170 DOI: 10.1007/s11596-018-1864-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2017] [Revised: 09/13/2017] [Indexed: 01/25/2023]
Abstract
This study was designed to evaluate the effects of testosterone supplementation (TS) on body composition in patients with HIV and the side effects of TS. A comprehensive literature search strategy was used to retrieve relevant randomized controlled trials (RCTs) examining the effects of TS on body composition. Atotal of 14 eligible studies were included, enrolling 388 and 349 randomized patients in TS and control groups, respectively. The quality of studies included was assessed, and data on total body weight (BW), lean body mass (LBM), fat mass (FM), serum total testosterone (TT), free testosterone (FT) levels, and adverse events were extracted and analyzed using Review Manager software 5.3. Meta-analysis results showed that TS was associated with a small but significant modification in total BW, serum TT, and FT levels in HIV-infected patients and in patients given various drug administrations. TS also significantly increased LBM in male patients, but no significant difference in LBM was observed between female counterparts treated with TS or not. Conversely, TS relative to placebo did not lead to a significant reduction in FM. No significant difference was observed between the two groups in terms of adverse effects. Our findings suggested that TS may be recommended to improve body composition in patients with HIV-related weight loss. However, owing to the high heterogeneity across included trials, further evaluations using large-scale, multi-center, blinded RCTs are needed.
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Affiliation(s)
- Ting Zhou
- Family Planning Research Institute, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Zhi-Yong Hu
- Family Planning Research Institute, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Hui-Ping Zhang
- Family Planning Research Institute, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Kai Zhao
- Family Planning Research Institute, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Yu Zhang
- Family Planning Research Institute, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Ying Li
- Family Planning Research Institute, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Jia-Jing Wei
- Family Planning Research Institute, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Hong-Fang Yuan
- Family Planning Research Institute, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China.
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53
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Testosterone boosts physical activity in male mice via dopaminergic pathways. Sci Rep 2018; 8:957. [PMID: 29343749 PMCID: PMC5772634 DOI: 10.1038/s41598-017-19104-0] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Accepted: 12/21/2017] [Indexed: 12/21/2022] Open
Abstract
Low testosterone (T) in men, especially its free fraction, has been associated with loss of energy. In accordance, orchidectomy (ORX) in rodents results in decreased physical activity. Still, the mechanisms through which T stimulates activity remain mostly obscure. Here, we studied voluntary wheel running behavior in three different mouse models of androgen deficiency: ORX, androgen receptor (AR) knock-out (ARKO) and sex hormone binding globulin (SHBG)-transgenic mice, a novel mouse model of “low free T”. Our results clearly show a fast and dramatic action of T stimulating wheel running, which is not explained by its action on muscle, as evidenced by neuromuscular studies and in a muscle-specific conditional ARKO mouse model. The action of T occurs via its free fraction, as shown by the results in SHBG-transgenic mice, and it implies both androgenic and estrogenic pathways. Both gene expression and functional studies indicate that T modulates the in vivo sensitivity to dopamine (DA) agonists. Furthermore, the restoration of wheel running by T is inhibited by treatment with DA antagonists. These findings reveal that the free fraction of T, both via AR and indirectly through aromatization into estrogens, stimulates physical activity behavior in male mice by acting on central DA pathways.
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54
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Cheung AS, de Rooy C, Levinger I, Rana K, Clarke MV, How JM, Garnham A, McLean C, Zajac JD, Davey RA, Grossmann M. Actin alpha cardiac muscle 1 gene expression is upregulated in the skeletal muscle of men undergoing androgen deprivation therapy for prostate cancer. J Steroid Biochem Mol Biol 2017; 174:56-64. [PMID: 28756295 DOI: 10.1016/j.jsbmb.2017.07.029] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/18/2017] [Revised: 07/24/2017] [Accepted: 07/25/2017] [Indexed: 02/06/2023]
Abstract
Androgen deprivation therapy (ADT) decreases muscle mass and function but no human studies have investigated the underlying genetic or cellular effects. We tested the hypothesis that ADT will lead to changes in skeletal muscle gene expression, which may explain the adverse muscle phenotype seen clinically. We conducted a prospective cohort study of 9 men with localised prostate cancer who underwent a vastus lateralis biopsy before and after 4 weeks of ADT. Next-generation RNA sequencing was performed and genes differentially expressed following ADT underwent gene ontology mining using Ingenuity Pathway Analysis. Differential expression of genes of interest was confirmed by quantitative PCR (Q-PCR) on gastrocnemius muscle of orchidectomised mice and sham controls (n=11/group). We found that in men, circulating total testosterone decreased from 16.5±4.3nmol/L at baseline to 0.4±0.15nmol/L post-ADT (p<0.001). RNA sequencing identified 19 differentially expressed genes post-ADT (all p<0.05 after adjusting for multiple testing). Gene ontology mining identified 8 genes to be of particular interest due to known roles in androgen-mediated signalling; ABCG1, ACTC1, ANKRD1, DMPK, THY1, DCLK1, CST3 were upregulated and SLC38A3 was downregulated post-ADT. Q-PCR in mouse gastrocnemius muscle confirmed that only one gene, Actc1 was concordantly upregulated (p<0.01) in orchidectomised mice compared with controls. In conclusion, given that ACTC1 upregulation is associated with improved muscle function in certain myopathies, we hypothesise that upregulation of ACTC1 may represent a compensatory response to ADT-induced muscle loss. Further studies will be required to evaluate the role and function of ACTC1.
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Affiliation(s)
- Ada S Cheung
- Department of Medicine (Austin Health), The University of Melbourne, Heidelberg, Victoria, Australia; Department of Endocrinology, Austin Health, Heidelberg, Victoria, Australia.
| | - Casey de Rooy
- Department of Medicine (Austin Health), The University of Melbourne, Heidelberg, Victoria, Australia
| | - Itamar Levinger
- Institute of Sport, Exercise, and Active Living (ISEAL), Victoria University, Victoria, Australia; Australian Institute for Musculoskeletal Science (AIMSS), Western Health, St. Albans, VIC, Australia
| | - Kesha Rana
- Department of Medicine (Austin Health), The University of Melbourne, Heidelberg, Victoria, Australia
| | - Michele V Clarke
- Department of Medicine (Austin Health), The University of Melbourne, Heidelberg, Victoria, Australia
| | - Jackie M How
- Department of Medicine (Austin Health), The University of Melbourne, Heidelberg, Victoria, Australia
| | - Andrew Garnham
- Centre for Physical Activity and Nutrition, School of Exercise and Nutrition Sciences, Deakin University, Burwood, Victoria, Australia
| | | | - Jeffrey D Zajac
- Department of Medicine (Austin Health), The University of Melbourne, Heidelberg, Victoria, Australia; Department of Endocrinology, Austin Health, Heidelberg, Victoria, Australia
| | - Rachel A Davey
- Department of Medicine (Austin Health), The University of Melbourne, Heidelberg, Victoria, Australia
| | - Mathis Grossmann
- Department of Medicine (Austin Health), The University of Melbourne, Heidelberg, Victoria, Australia; Department of Endocrinology, Austin Health, Heidelberg, Victoria, Australia
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55
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da Rocha AL, Pereira BC, Teixeira GR, Pinto AP, Frantz FG, Elias LLK, Lira FS, Pauli JR, Cintra DE, Ropelle ER, de Moura LP, Mekary RA, de Freitas EC, da Silva ASR. Treadmill Slope Modulates Inflammation, Fiber Type Composition, Androgen, and Glucocorticoid Receptors in the Skeletal Muscle of Overtrained Mice. Front Immunol 2017; 8:1378. [PMID: 29163473 PMCID: PMC5669301 DOI: 10.3389/fimmu.2017.01378] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2017] [Accepted: 10/06/2017] [Indexed: 12/16/2022] Open
Abstract
Overtraining (OT) may be defined as an imbalance between excessive training and adequate recovery period. Recently, a downhill running-based overtraining (OTR/down) protocol induced the nonfunctional overreaching state, which is defined as a performance decrement that may be associated with psychological and hormonal disruptions and promoted intramuscular and systemic inflammation. To discriminate the eccentric contraction effects on interleukin 1beta (IL-1β), IL-6, IL-10, IL-15, and SOCS-3, we compared the release of these cytokines in OTR/down with other two OT protocols with the same external load (i.e., the product between training intensity and volume), but performed in uphill (OTR/up) and without inclination (OTR). Also, we evaluated the effects of these OT models on the muscle morphology and fiber type composition, serum levels of fatigue markers and corticosterone, as well as androgen receptor (AR) and glucocorticoid receptor (GR) expressions. For extensor digitorum longus (EDL), OTR/down and OTR groups increased the cytokines and exhibited micro-injuries with polymorphonuclear infiltration. While OTR/down group increased the cytokines in soleus muscle, OTR/up group only increased IL-6. All OT groups presented micro-injuries with polymorphonuclear infiltration. In serum, while OTR/down and OTR/up protocols increased IL-1β, IL-6, and tumor necrosis factor alpha, OTR group increased IL-1β, IL-6, IL-15, and corticosterone. The type II fibers in EDL and soleus, total and phosphorylated AR levels in soleus, and total GR levels in EDL and soleus were differentially modulated by the OT protocols. In summary, the proinflammatory cytokines were more sensitive for OTR/down than for OTR/up and OTR. Also, the specific treadmill inclination of each OT model influenced most of the other evaluated parameters.
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Affiliation(s)
- Alisson L da Rocha
- Postgraduate Program in Rehabilitation and Functional Performance, Ribeirão Preto Medical School, University of São Paulo (USP), Ribeirão Preto, Brazil
| | - Bruno C Pereira
- Postgraduate Program in Rehabilitation and Functional Performance, Ribeirão Preto Medical School, University of São Paulo (USP), Ribeirão Preto, Brazil
| | - Giovana R Teixeira
- Department of Physical Education, State University of São Paulo (UNESP), Presidente Prudente, Brazil
| | - Ana P Pinto
- Postgraduate Program in Rehabilitation and Functional Performance, Ribeirão Preto Medical School, University of São Paulo (USP), Ribeirão Preto, Brazil
| | - Fabiani G Frantz
- Department of Clinical, Toxicological, and Bromatological Analysis, Faculty of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo (USP), Ribeirão Preto, Brazil
| | - Lucila L K Elias
- Department of Physiology, Ribeirao Preto Medical School, University of São Paulo (USP), Ribeirão Preto, Brazil
| | - Fábio S Lira
- Department of Physical Education, State University of São Paulo (UNESP), Presidente Prudente, Brazil
| | - José R Pauli
- Laboratory of Molecular Biology of Exercise (LaBMEx), School of Applied Sciences, University of Campinas (UNICAMP), Campinas, Brazil
| | - Dennys E Cintra
- Laboratory of Molecular Biology of Exercise (LaBMEx), School of Applied Sciences, University of Campinas (UNICAMP), Campinas, Brazil
| | - Eduardo R Ropelle
- Laboratory of Molecular Biology of Exercise (LaBMEx), School of Applied Sciences, University of Campinas (UNICAMP), Campinas, Brazil
| | - Leandro P de Moura
- Laboratory of Molecular Biology of Exercise (LaBMEx), School of Applied Sciences, University of Campinas (UNICAMP), Campinas, Brazil
| | - Rania A Mekary
- Department of Pharmaceutical Business and Administrative Sciences, MCPHS University, Boston, MA, United States.,Department of Surgery, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, United States
| | - Ellen C de Freitas
- School of Physical Education and Sport of Ribeirão Preto, University of São Paulo (USP), Ribeirão Preto, Brazil
| | - Adelino S R da Silva
- Postgraduate Program in Rehabilitation and Functional Performance, Ribeirão Preto Medical School, University of São Paulo (USP), Ribeirão Preto, Brazil.,School of Physical Education and Sport of Ribeirão Preto, University of São Paulo (USP), Ribeirão Preto, Brazil
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56
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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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57
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Ma Y, Fu S, Lu L, Wang X. Role of androgen receptor on cyclic mechanical stretch-regulated proliferation of C2C12 myoblasts and its upstream signals: IGF-1-mediated PI3K/Akt and MAPKs pathways. Mol Cell Endocrinol 2017; 450:83-93. [PMID: 28454723 DOI: 10.1016/j.mce.2017.04.021] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Revised: 04/17/2017] [Accepted: 04/24/2017] [Indexed: 12/28/2022]
Abstract
OBJECTS To detect the effects of androgen receptor (AR) on cyclic mechanical stretch-modulated proliferation of C2C12 myoblasts and its pathways: roles of IGF-1, PI3K and MAPK. METHODS C2C12 were randomly divided into five groups: un-stretched control, six or 8 h of fifteen percent stretch, and six or 8 h of twenty percent stretch. Cyclic mechanical stretch of C2C12 were completed using a computer-controlled FlexCell Strain Unit. Cell proliferation and IGF-1 concentration in medium were detected by CCK8 and ELISA, respectively. Expressions of AR and IGF-1R, and expressions and activities of PI3K, p38 and ERK1/2 in stretched C2C12 cells were determined by Western blot. RESULTS ①The proliferation of C2C12 cells, IGF-1 concentration in medium, expressions of AR and IGF-1R, and activities of PI3K, p38 and ERK1/2 were increased by 6 h of fifteen percent stretch, while decreased by twenty percent stretch for six or 8 h ②The fifteen percent stretch-increased proliferation of C2C12 cells was reversed by AR inhibitor, Flutamide. ③The increases of AR expression, activities of PI3K, p38 and ERK1/2 resulted from fifteen percent stretch were attenuated by IGF-1 neutralizing antibody, while twenty percent stretch-induced decreases of the above indicators were enhanced by recombinant IGF-1. ④Specific inhibitors of p38, ERK1/2 and PI3K all decreased the expression of AR in fifteen percent and twenty percent of stretched C2C12 cells. CONCLUSIONS Cyclic mechanical stretch modulated the proliferation of C2C12 cells, which may be attributed to the alterations of AR via IGF-1-PI3K/Akt and IGF-1-MAPK (p38, ERK1/2) pathways in C2C12 cells.
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Affiliation(s)
- Yiming Ma
- School of Kinesiology, Shanghai University of Sport, Shanghai 200438, China
| | - Shaoting Fu
- School of Kinesiology, Shanghai University of Sport, Shanghai 200438, China
| | - Lin Lu
- School of Kinesiology, Shanghai University of Sport, Shanghai 200438, China
| | - Xiaohui Wang
- School of Kinesiology, Shanghai University of Sport, Shanghai 200438, China.
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Ueberschlag-Pitiot V, Stantzou A, Messéant J, Lemaitre M, Owens DJ, Noirez P, Roy P, Agbulut O, Metzger D, Ferry A. Gonad-related factors promote muscle performance gain during postnatal development in male and female mice. Am J Physiol Endocrinol Metab 2017; 313:E12-E25. [PMID: 28351832 DOI: 10.1152/ajpendo.00446.2016] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/13/2016] [Revised: 02/22/2017] [Accepted: 03/22/2017] [Indexed: 11/22/2022]
Abstract
To better define the role of male and female gonad-related factors (MGRF, presumably testosterone, and FGRF, presumably estradiol, respectively) on mouse hindlimb skeletal muscle contractile performance/function gain during postnatal development, we analyzed the effect of castration initiated before puberty in male and female mice. We found that muscle absolute and specific (normalized to muscle weight) maximal forces were decreased in 6-mo-old male and female castrated mice compared with age- and sex-matched intact mice, without alteration in neuromuscular transmission. Moreover, castration decreased absolute and specific maximal powers, another important aspect of muscle performance, in 6-mo-old males, but not in females. Absolute maximal force was similarly reduced by castration in 3-mo-old muscle fiber androgen receptor (AR)-deficient and wild-type male mice, indicating that the effect of MGRF was muscle fiber AR independent. Castration reduced the muscle weight gain in 3-mo mice of both sexes and in 6-mo females but not in males. We also found that bone morphogenetic protein signaling through Smad1/5/9 was not altered by castration in atrophic muscle of 3-mo-old mice of both sexes. Moreover, castration decreased the sexual dimorphism regarding muscle performance. Together, these results demonstrated that in the long term, MGRF and FGRF promote muscle performance gain in mice during postnatal development, independently of muscle growth in males, largely via improving muscle contractile quality (force and power normalized), and that MGFR and FGRF also contribute to sexual dimorphism. However, the mechanisms underlying MGFR and FGRF actions remain to be determined.
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Affiliation(s)
- Vanessa Ueberschlag-Pitiot
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Université de Strasbourg, CNRS UMR7104/INSERM U964, Illkirch, France
| | - Amalia Stantzou
- Sorbonne Universités, Université Pierre et Marie Curie-Paris6, Myology Research Center, UM76 and INSERM U974 and CNRS FRE 3617 and Institut de Myologie, Paris, France
| | - Julien Messéant
- Sorbonne Universités, Université Pierre et Marie Curie-Paris6, Myology Research Center, UM76 and INSERM U974 and CNRS FRE 3617 and Institut de Myologie, Paris, France
| | - Megane Lemaitre
- Sorbonne Universités, Université Pierre et Marie Curie-Paris6, Myology Research Center, UM76 and INSERM U974 and CNRS FRE 3617 and Institut de Myologie, Paris, France
| | - Daniel J Owens
- Sorbonne Universités, Université Pierre et Marie Curie-Paris6, Myology Research Center, UM76 and INSERM U974 and CNRS FRE 3617 and Institut de Myologie, Paris, France
| | - Philippe Noirez
- Institut de Recherche Biomédicale et D'épidemiologie du Sport, EA 7329, Institut National du Sport de l'Expertise et de la Performance, Laboratory of Excellence GR-Ex, Paris, France
- Université Sorbonne Paris Cité, Université Paris Descartes, Paris, France; and
| | - Pauline Roy
- Sorbonne Universités, Université Pierre et Marie Curie-Paris6, Myology Research Center, UM76 and INSERM U974 and CNRS FRE 3617 and Institut de Myologie, Paris, France
| | - Onnik Agbulut
- Sorbonne Universités, Université Pierre et Marie Curie-Paris6, Institut de Biologie Paris-Seine, UMR CNRS 8256, Biological Adaptation and Ageing, Paris, France
| | - Daniel Metzger
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Université de Strasbourg, CNRS UMR7104/INSERM U964, Illkirch, France
| | - Arnaud Ferry
- Sorbonne Universités, Université Pierre et Marie Curie-Paris6, Myology Research Center, UM76 and INSERM U974 and CNRS FRE 3617 and Institut de Myologie, Paris, France;
- Université Sorbonne Paris Cité, Université Paris Descartes, Paris, France; and
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59
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Swift-Gallant A, Monks DA. Androgenic mechanisms of sexual differentiation of the nervous system and behavior. Front Neuroendocrinol 2017; 46:32-45. [PMID: 28455096 DOI: 10.1016/j.yfrne.2017.04.003] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/22/2017] [Revised: 04/21/2017] [Accepted: 04/24/2017] [Indexed: 01/23/2023]
Abstract
Testicular androgens are the major endocrine factor promoting masculine phenotypes in vertebrates, but androgen signaling is complex and operates via multiple signaling pathways and sites of action. Recently, selective androgen receptor mutants have been engineered to study androgenic mechanisms of sexual differentiation of the nervous system and behavior. The focus of these studies has been to evaluate androgenic mechanisms within the nervous system by manipulating androgen receptor conditionally in neural tissues. Here we review both the effects of neural loss of AR function as well as the effects of neural overexpression of AR in relation to global AR mutants. Although some studies have conformed to our expectations, others have proved challenging to assumptions underlying the dominant hypotheses. Notably, these studies have called into question both the primacy of direct, neural mechanisms and also the linearity of the relationship between androgenic dose and sexual differentiation of brain and behavior.
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Affiliation(s)
- A Swift-Gallant
- Department of Psychology, University of Toronto, 100 St. George Street, Toronto, ON M5S 3G3, Canada; Department of Psychology, University of Toronto Mississauga, 3359 Mississauga Rd. N., Mississauga, ON L5L 1C6, Canada
| | - D A Monks
- Department of Psychology, University of Toronto, 100 St. George Street, Toronto, ON M5S 3G3, Canada; Department of Cells and Systems Biology, University of Toronto, 100 St. George Street, Toronto, ON M5S 3G3, Canada; Department of Psychology, University of Toronto Mississauga, 3359 Mississauga Rd. N., Mississauga, ON L5L 1C6, Canada.
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60
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Kovanecz I, Masouminia M, Gelfand R, Vernet D, Rajfer J, Gonzalez-Cadavid NF. Myostatin, a profibrotic factor and the main inhibitor of striated muscle mass, is present in the penile and vascular smooth muscle. Int J Impot Res 2017; 29:194-201. [PMID: 28539643 DOI: 10.1038/ijir.2017.22] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2015] [Revised: 03/20/2017] [Accepted: 03/30/2017] [Indexed: 12/13/2022]
Abstract
Myostatin is present in striated myofibers but, except for myometrial cells, has not been reported within smooth muscle cells (SMC). We investigated in the rat whether myostatin is present in SMC within the penis and the vascular wall and, if so, whether it is transcriptionally expressed and associated with the loss of corporal SMC occurring in certain forms of erectile dysfunction (ED). Myostatin protein was detected by immunohistochemistry/fluorescence and western blots in the perineal striated muscles, and also in the SMC of the penile corpora, arteries and veins, and aorta. Myostatin was found in corporal SMC cultures, and its transcriptional expression (and its receptor) was shown there by DNA microarrays. Myostatin protein was measured by western blots in the penile shaft of rats subjected to bilateral cavernosal nerve resection (BCNR), that were left untreated, or treated (45 days) with muscle-derived stem cells (MDSC), or concurrent daily low-dose sildenafil. Myostatin was not increased by BCNR (compared with sham operated animals), but over expressed after treatment with MDSC. This was reduced by concurrent sildenafil. The presence of myostatin in corporal and vascular SMC, and its overexpression in the corpora by MDSC therapy, may have relevance for the stem cell treatment of corporal fibrosis and ED.
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Affiliation(s)
- I Kovanecz
- Division of Urology, Department of Surgery, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, CA, USA.,Department of Urology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - M Masouminia
- Division of Urology, Department of Surgery, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, CA, USA
| | - R Gelfand
- Division of Urology, Department of Surgery, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, CA, USA.,Department of Medicine, Charles Drew University of Medicine and Science, Los Angeles, CA, USA
| | - D Vernet
- Division of Urology, Department of Surgery, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, CA, USA.,Department of Medicine, Charles Drew University of Medicine and Science, Los Angeles, CA, USA
| | - J Rajfer
- Division of Urology, Department of Surgery, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, CA, USA.,Department of Urology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - N F Gonzalez-Cadavid
- Division of Urology, Department of Surgery, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, CA, USA.,Department of Urology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA.,Department of Medicine, Charles Drew University of Medicine and Science, Los Angeles, CA, USA
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Rossetti ML, Steiner JL, Gordon BS. Androgen-mediated regulation of skeletal muscle protein balance. Mol Cell Endocrinol 2017; 447:35-44. [PMID: 28237723 PMCID: PMC5407187 DOI: 10.1016/j.mce.2017.02.031] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/06/2017] [Revised: 02/20/2017] [Accepted: 02/20/2017] [Indexed: 02/06/2023]
Abstract
Androgens significantly alter muscle mass in part by shifting protein balance in favor of net protein accretion. During various atrophic conditions, the clinical impact of decreased production or bioavailability of androgens (termed hypogonadism) is important as a loss of muscle mass is intimately linked with survival outcome. While androgen replacement therapy increases muscle mass in part by restoring protein balance, this is not a comprehensive treatment option due to potential side effects. Therefore, an understanding of the mechanisms by which androgens alter protein balance is needed for the development of androgen-independent therapies. While the data in humans suggest androgens alter protein balance (both synthesis and breakdown) in the fasted metabolic state, a predominant molecular mechanism(s) behind this observation is still lacking. This failure is likely due in part to inconsistent experimental design between studies including failure to control nutrient/feeding status, the method of altering androgens, and the model systems utilized.
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Affiliation(s)
- Michael L Rossetti
- The Institute of Exercise Physiology and Wellness, The University of Central Florida, PO Box 161250, Orlando, FL 32816, United States
| | - Jennifer L Steiner
- Department of Cellular and Molecular Physiology, The Pennsylvania State University College of Medicine, 500 University Drive, Hershey, PA 17033, United States
| | - Bradley S Gordon
- The Institute of Exercise Physiology and Wellness, The University of Central Florida, PO Box 161250, Orlando, FL 32816, United States.
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Kraemer WJ, Ratamess NA, Nindl BC. Recovery responses of testosterone, growth hormone, and IGF-1 after resistance exercise. J Appl Physiol (1985) 2017; 122:549-558. [DOI: 10.1152/japplphysiol.00599.2016] [Citation(s) in RCA: 71] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Revised: 11/01/2016] [Accepted: 11/08/2016] [Indexed: 12/30/2022] Open
Abstract
The complexity and redundancy of the endocrine pathways during recovery related to anabolic function in the body belie an oversimplistic approach to its study. The purpose of this review is to examine the role of resistance exercise (RE) on the recovery responses of three major anabolic hormones, testosterone, growth hormone(s), and insulin-like growth factor 1. Each hormone has a complexity related to differential pathways of action as well as interactions with binding proteins and receptor interactions. Testosterone is the primary anabolic hormone, and its concentration changes during the recovery period depending on the upregulation or downregulation of the androgen receptor. Multiple tissues beyond skeletal muscle are targeted under hormonal control and play critical roles in metabolism and physiological function. Growth hormone (GH) demonstrates differential increases in recovery with RE based on the type of GH being assayed and workout being used. IGF-1 shows variable increases in recovery with RE and is intimately linked to a host of binding proteins that are essential to its integrative actions and mediating targeting effects. The RE stress is related to recruitment of muscle tissue with the glandular release of hormones as signals to target tissues to support homeostatic mechanisms for metabolism and tissue repair during the recovery process. Anabolic hormones play a crucial role in the body’s response to metabolism, repair, and adaptive capabilities especially in response to anabolic-type RE. Changes of these hormones following RE during recovery in the circulatory biocompartment of blood are reflective of the many mechanisms of action that are in play in the repair and recovery process.
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Affiliation(s)
| | - Nicholas A. Ratamess
- Department of Health and Exercise Science, The College of New Jersey, Ewing, New Jersey; and
| | - Bradley C. Nindl
- Department of Sports Medicine and Nutrition, University of Pittsburgh, Pittsburgh, Pennsylvania
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Kong BW, Hudson N, Seo D, Lee S, Khatri B, Lassiter K, Cook D, Piekarski A, Dridi S, Anthony N, Bottje W. RNA sequencing for global gene expression associated with muscle growth in a single male modern broiler line compared to a foundational Barred Plymouth Rock chicken line. BMC Genomics 2017; 18:82. [PMID: 28086790 PMCID: PMC5237145 DOI: 10.1186/s12864-016-3471-y] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2016] [Accepted: 12/23/2016] [Indexed: 01/08/2023] Open
Abstract
Background Modern broiler chickens exhibit very rapid growth and high feed efficiency compared to unselected chicken breeds. The improved production efficiency in modern broiler chickens was achieved by the intensive genetic selection for meat production. This study was designed to investigate the genetic alterations accumulated in modern broiler breeder lines during selective breeding conducted over several decades. Methods To identify genes important in determining muscle growth and feed efficiency in broilers, RNA sequencing (RNAseq) was conducted with breast muscle in modern pedigree male (PeM) broilers (n = 6 per group), and with an unselected foundation broiler line (Barred Plymouth Rock; BPR). The RNAseq analysis was carried out using Ilumina Hiseq (2 x 100 bp paired end read) and raw reads were assembled with the galgal4 reference chicken genome. With normalized RPM values, genes showing >10 average read counts were chosen and genes showing <0.05 p-value and >1.3 fold change were considered as differentially expressed (DE) between PeM and BPR. DE genes were subjected to Ingenuity Pathway Analysis (IPA) for bioinformatic functional interpretation. Results The results indicate that 2,464 DE genes were identified in the comparison between PeM and BPR. Interestingly, the expression of genes encoding mitochondrial proteins in chicken are significantly biased towards the BPR group, suggesting a lowered mitochondrial content in PeM chicken muscles compared to BPR chicken. This result is inconsistent with more slow muscle fibers bearing a lower mitochondrial content in the PeM. The molecular, cellular and physiological functions of DE genes in the comparison between PeM and BPR include organismal injury, carbohydrate metabolism, cell growth/proliferation, and skeletal muscle system development, indicating that cellular mechanisms in modern broiler lines are tightly associated with rapid growth and differential muscle fiber contents compared to the unselected BPR line. Particularly, PDGF (platelet derived growth factor) signaling and NFE2L2 (nuclear factor, erythroid 2-like 2; also known as NRF2) mediated oxidative stress response pathways appear to be activated in modern broiler compared to the foundational BPR line. Upstream and network analyses revealed that the MSTN (myostatin) –FST (follistatin) interactions and inhibition of AR (androgen receptor) were predicted to be effective regulatory factors for DE genes in modern broiler line. PRKAG3 (protein kinase, AMP-activated, gamma 3 non-catalytic subunit) and LIPE (lipase E) are predicted as core regulatory factors for myogenic development, nutrient and lipid metabolism. Conclusion The highly upregulated genes in PeM may represent phenotypes of subclinical myopathy commonly observed in the commercial broiler breast tissue, that can lead to muscle hardening, named as woody breast. By investigating global gene expression in a highly selected pedigree broiler line and a foundational breed (Barred Plymouth Rock), the results provide insight into cellular mechanisms that regulate muscle growth, fiber composition and feed efficiency. Electronic supplementary material The online version of this article (doi:10.1186/s12864-016-3471-y) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Byung-Whi Kong
- Department of Poultry Science, Center of Excellence for Poultry Science, University of Arkansas, Fayetteville, Arkansas, USA
| | - Nicholas Hudson
- School of Agriculture and Food Science, University of Queensland, Gatton, Australia
| | - Dongwon Seo
- Department of Poultry Science, Center of Excellence for Poultry Science, University of Arkansas, Fayetteville, Arkansas, USA
| | - Seok Lee
- Department of Poultry Science, Center of Excellence for Poultry Science, University of Arkansas, Fayetteville, Arkansas, USA
| | - Bhuwan Khatri
- Department of Poultry Science, Center of Excellence for Poultry Science, University of Arkansas, Fayetteville, Arkansas, USA
| | - Kentu Lassiter
- Department of Poultry Science, Center of Excellence for Poultry Science, University of Arkansas, Fayetteville, Arkansas, USA
| | - Devin Cook
- Department of Poultry Science, Center of Excellence for Poultry Science, University of Arkansas, Fayetteville, Arkansas, USA
| | - Alissa Piekarski
- Department of Poultry Science, Center of Excellence for Poultry Science, University of Arkansas, Fayetteville, Arkansas, USA
| | - Sami Dridi
- Department of Poultry Science, Center of Excellence for Poultry Science, University of Arkansas, Fayetteville, Arkansas, USA
| | - Nicholas Anthony
- Department of Poultry Science, Center of Excellence for Poultry Science, University of Arkansas, Fayetteville, Arkansas, USA
| | - Walter Bottje
- Department of Poultry Science, Center of Excellence for Poultry Science, University of Arkansas, Fayetteville, Arkansas, USA.
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65
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Almeida M, Laurent MR, Dubois V, Claessens F, O'Brien CA, Bouillon R, Vanderschueren D, Manolagas SC. Estrogens and Androgens in Skeletal Physiology and Pathophysiology. Physiol Rev 2017; 97:135-187. [PMID: 27807202 PMCID: PMC5539371 DOI: 10.1152/physrev.00033.2015] [Citation(s) in RCA: 460] [Impact Index Per Article: 65.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Estrogens and androgens influence the growth and maintenance of the mammalian skeleton and are responsible for its sexual dimorphism. Estrogen deficiency at menopause or loss of both estrogens and androgens in elderly men contribute to the development of osteoporosis, one of the most common and impactful metabolic diseases of old age. In the last 20 years, basic and clinical research advances, genetic insights from humans and rodents, and newer imaging technologies have changed considerably the landscape of our understanding of bone biology as well as the relationship between sex steroids and the physiology and pathophysiology of bone metabolism. Together with the appreciation of the side effects of estrogen-related therapies on breast cancer and cardiovascular diseases, these advances have also drastically altered the treatment of osteoporosis. In this article, we provide a comprehensive review of the molecular and cellular mechanisms of action of estrogens and androgens on bone, their influences on skeletal homeostasis during growth and adulthood, the pathogenetic mechanisms of the adverse effects of their deficiency on the female and male skeleton, as well as the role of natural and synthetic estrogenic or androgenic compounds in the pharmacotherapy of osteoporosis. We highlight latest advances on the crosstalk between hormonal and mechanical signals, the relevance of the antioxidant properties of estrogens and androgens, the difference of their cellular targets in different bone envelopes, the role of estrogen deficiency in male osteoporosis, and the contribution of estrogen or androgen deficiency to the monomorphic effects of aging on skeletal involution.
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Affiliation(s)
- Maria Almeida
- Division of Endocrinology and Metabolism, Center for Osteoporosis and Metabolic Bone Diseases, University of Arkansas for Medical Sciences and the Central Arkansas Veterans Healthcare System, Little Rock, Arkansas; Departments of Cellular and Molecular Medicine and Clinical and Experimental Medicine, KU Leuven, Leuven, Belgium; Center for Metabolic Bone Diseases, University Hospitals Leuven, Leuven, Belgium; and Institut National de la Santé et de la Recherche Médicale UMR1011, University of Lille and Institut Pasteur de Lille, Lille, France
| | - Michaël R Laurent
- Division of Endocrinology and Metabolism, Center for Osteoporosis and Metabolic Bone Diseases, University of Arkansas for Medical Sciences and the Central Arkansas Veterans Healthcare System, Little Rock, Arkansas; Departments of Cellular and Molecular Medicine and Clinical and Experimental Medicine, KU Leuven, Leuven, Belgium; Center for Metabolic Bone Diseases, University Hospitals Leuven, Leuven, Belgium; and Institut National de la Santé et de la Recherche Médicale UMR1011, University of Lille and Institut Pasteur de Lille, Lille, France
| | - Vanessa Dubois
- Division of Endocrinology and Metabolism, Center for Osteoporosis and Metabolic Bone Diseases, University of Arkansas for Medical Sciences and the Central Arkansas Veterans Healthcare System, Little Rock, Arkansas; Departments of Cellular and Molecular Medicine and Clinical and Experimental Medicine, KU Leuven, Leuven, Belgium; Center for Metabolic Bone Diseases, University Hospitals Leuven, Leuven, Belgium; and Institut National de la Santé et de la Recherche Médicale UMR1011, University of Lille and Institut Pasteur de Lille, Lille, France
| | - Frank Claessens
- Division of Endocrinology and Metabolism, Center for Osteoporosis and Metabolic Bone Diseases, University of Arkansas for Medical Sciences and the Central Arkansas Veterans Healthcare System, Little Rock, Arkansas; Departments of Cellular and Molecular Medicine and Clinical and Experimental Medicine, KU Leuven, Leuven, Belgium; Center for Metabolic Bone Diseases, University Hospitals Leuven, Leuven, Belgium; and Institut National de la Santé et de la Recherche Médicale UMR1011, University of Lille and Institut Pasteur de Lille, Lille, France
| | - Charles A O'Brien
- Division of Endocrinology and Metabolism, Center for Osteoporosis and Metabolic Bone Diseases, University of Arkansas for Medical Sciences and the Central Arkansas Veterans Healthcare System, Little Rock, Arkansas; Departments of Cellular and Molecular Medicine and Clinical and Experimental Medicine, KU Leuven, Leuven, Belgium; Center for Metabolic Bone Diseases, University Hospitals Leuven, Leuven, Belgium; and Institut National de la Santé et de la Recherche Médicale UMR1011, University of Lille and Institut Pasteur de Lille, Lille, France
| | - Roger Bouillon
- Division of Endocrinology and Metabolism, Center for Osteoporosis and Metabolic Bone Diseases, University of Arkansas for Medical Sciences and the Central Arkansas Veterans Healthcare System, Little Rock, Arkansas; Departments of Cellular and Molecular Medicine and Clinical and Experimental Medicine, KU Leuven, Leuven, Belgium; Center for Metabolic Bone Diseases, University Hospitals Leuven, Leuven, Belgium; and Institut National de la Santé et de la Recherche Médicale UMR1011, University of Lille and Institut Pasteur de Lille, Lille, France
| | - Dirk Vanderschueren
- Division of Endocrinology and Metabolism, Center for Osteoporosis and Metabolic Bone Diseases, University of Arkansas for Medical Sciences and the Central Arkansas Veterans Healthcare System, Little Rock, Arkansas; Departments of Cellular and Molecular Medicine and Clinical and Experimental Medicine, KU Leuven, Leuven, Belgium; Center for Metabolic Bone Diseases, University Hospitals Leuven, Leuven, Belgium; and Institut National de la Santé et de la Recherche Médicale UMR1011, University of Lille and Institut Pasteur de Lille, Lille, France
| | - Stavros C Manolagas
- Division of Endocrinology and Metabolism, Center for Osteoporosis and Metabolic Bone Diseases, University of Arkansas for Medical Sciences and the Central Arkansas Veterans Healthcare System, Little Rock, Arkansas; Departments of Cellular and Molecular Medicine and Clinical and Experimental Medicine, KU Leuven, Leuven, Belgium; Center for Metabolic Bone Diseases, University Hospitals Leuven, Leuven, Belgium; and Institut National de la Santé et de la Recherche Médicale UMR1011, University of Lille and Institut Pasteur de Lille, Lille, France
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Laurent MR, Jardí F, Dubois V, Schollaert D, Khalil R, Gielen E, Carmeliet G, Claessens F, Vanderschueren D. Androgens have antiresorptive effects on trabecular disuse osteopenia independent from muscle atrophy. Bone 2016; 93:33-42. [PMID: 27622887 DOI: 10.1016/j.bone.2016.09.011] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/07/2016] [Revised: 09/07/2016] [Accepted: 09/09/2016] [Indexed: 12/18/2022]
Abstract
Aging hypogonadal men are at increased risk of osteoporosis and sarcopenia. Testosterone is a potentially appealing strategy to prevent simultaneous bone and muscle loss. The androgen receptor (AR) mediates antiresorptive effects on trabecular bone via osteoblast-lineage cells, as well as muscle-anabolic actions. Sex steroids also modify the skeletal response to mechanical loading. However, it is unclear whether the effects of androgens on bone remain effective independent of mechanical stimulation or rather require indirect androgen effects via muscle. This study aims to characterize the effects and underlying mechanisms of androgens on disuse osteosarcopenia. Adult male mice received a unilateral botulinum toxin (BTx) injection, and underwent sham surgery or orchidectomy (ORX) without or with testosterone (ORX+T) or dihydrotestosterone (ORX+DHT) replacement. Compared to the contralateral internal control hindlimb, acute trabecular number and bone volume loss was increased by ORX and partially prevented DHT. T was more efficient and increased BV/TV in both hindlimbs over sham values, although it did not reduce the detrimental effect of BTx. Both androgens and BTx regulated trabecular osteoclast surface as well as tartrate-resistant acid phosphatase expression. Androgens also prevented BTx-induced body weight loss but did not significantly influence paralysis or muscle atrophy. BTx and ORX both reduced cortical thickness via endosteal expansion, which was prevented by T but not DHT. In long-term follow-up, the residual trabecular bone volume deficit in sham-BTx hindlimbs was prevented by DHT but T restored it more efficiently to pre-treatment levels. Conditional AR deletion in late osteoblasts and osteocytes or in the satellite cell lineage increased age-related trabecular bone loss in both hindlimbs without influencing the effect of BTx on trabecular osteopenia. We conclude that androgens have antiresorptive effects on trabecular disuse osteopenia which do not require AR actions on bone via muscle or via osteocytes.
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MESH Headings
- Acute Disease
- Androgens/pharmacology
- Androgens/therapeutic use
- Animals
- Body Weight
- Bone Diseases, Metabolic/complications
- Bone Diseases, Metabolic/drug therapy
- Bone Diseases, Metabolic/pathology
- Bone Diseases, Metabolic/physiopathology
- Bone Remodeling/drug effects
- Bone Resorption/complications
- Bone Resorption/drug therapy
- Bone Resorption/pathology
- Bone Resorption/physiopathology
- Calcification, Physiologic
- Cancellous Bone/diagnostic imaging
- Cancellous Bone/drug effects
- Cancellous Bone/pathology
- Cancellous Bone/physiopathology
- Cortical Bone/diagnostic imaging
- Cortical Bone/drug effects
- Cortical Bone/pathology
- Cortical Bone/physiopathology
- Extracellular Matrix Proteins/metabolism
- Female
- Gene Deletion
- Integrases/metabolism
- Male
- Mice, Inbred C57BL
- Muscular Atrophy/complications
- Muscular Atrophy/drug therapy
- Muscular Atrophy/pathology
- Muscular Atrophy/physiopathology
- Muscular Disorders, Atrophic/complications
- Muscular Disorders, Atrophic/drug therapy
- Muscular Disorders, Atrophic/pathology
- Muscular Disorders, Atrophic/physiopathology
- MyoD Protein/metabolism
- Organ Size
- Receptors, Androgen/metabolism
- X-Ray Microtomography
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Affiliation(s)
- Michaël R Laurent
- Laboratory of Molecular Endocrinology, Department of Cellular and Molecular Medicine, KU Leuven, Herestraat 49, PO box 901, 3000 Leuven, Belgium; Gerontology and Geriatrics, Department of Clinical and Experimental Medicine, KU Leuven, Herestraat 49, PO box 7003, 3000 Leuven, Belgium; Center for Metabolic Bone Diseases, University Hospitals Leuven, Herestraat 49, 3000 Leuven, Belgium.
| | - Ferran Jardí
- Clinical and Experimental Endocrinology, Department of Cellular and Molecular Medicine, KU Leuven, Herestraat 49, PO box 902, 3000 Leuven, Belgium.
| | - Vanessa Dubois
- Laboratory of Molecular Endocrinology, Department of Cellular and Molecular Medicine, KU Leuven, Herestraat 49, PO box 901, 3000 Leuven, Belgium.
| | - Dieter Schollaert
- Laboratory of Molecular Endocrinology, Department of Cellular and Molecular Medicine, KU Leuven, Herestraat 49, PO box 901, 3000 Leuven, Belgium.
| | - Rougin Khalil
- Clinical and Experimental Endocrinology, Department of Cellular and Molecular Medicine, KU Leuven, Herestraat 49, PO box 902, 3000 Leuven, Belgium.
| | - Evelien Gielen
- Gerontology and Geriatrics, Department of Clinical and Experimental Medicine, KU Leuven, Herestraat 49, PO box 7003, 3000 Leuven, Belgium; Center for Metabolic Bone Diseases, University Hospitals Leuven, Herestraat 49, 3000 Leuven, Belgium.
| | - Geert Carmeliet
- Clinical and Experimental Endocrinology, Department of Cellular and Molecular Medicine, KU Leuven, Herestraat 49, PO box 902, 3000 Leuven, Belgium.
| | - Frank Claessens
- Laboratory of Molecular Endocrinology, Department of Cellular and Molecular Medicine, KU Leuven, Herestraat 49, PO box 901, 3000 Leuven, Belgium.
| | - Dirk Vanderschueren
- Clinical and Experimental Endocrinology, Department of Cellular and Molecular Medicine, KU Leuven, Herestraat 49, PO box 902, 3000 Leuven, Belgium.
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Laurent MR, Dubois V, Claessens F, Verschueren SMP, Vanderschueren D, Gielen E, Jardí F. Muscle-bone interactions: From experimental models to the clinic? A critical update. Mol Cell Endocrinol 2016; 432:14-36. [PMID: 26506009 DOI: 10.1016/j.mce.2015.10.017] [Citation(s) in RCA: 91] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/31/2015] [Revised: 10/13/2015] [Accepted: 10/20/2015] [Indexed: 02/06/2023]
Abstract
Bone is a biomechanical tissue shaped by forces from muscles and gravitation. Simultaneous bone and muscle decay and dysfunction (osteosarcopenia or sarco-osteoporosis) is seen in ageing, numerous clinical situations including after stroke or paralysis, in neuromuscular dystrophies, glucocorticoid excess, or in association with vitamin D, growth hormone/insulin like growth factor or sex steroid deficiency, as well as in spaceflight. Physical exercise may be beneficial in these situations, but further work is still needed to translate acceptable and effective biomechanical interventions like vibration therapy from animal models to humans. Novel antiresorptive and anabolic therapies are emerging for osteoporosis as well as drugs for sarcopenia, cancer cachexia or muscle wasting disorders, including antibodies against myostatin or activin receptor type IIA and IIB (e.g. bimagrumab). Ideally, increasing muscle mass would increase muscle strength and restore bone loss from disuse. However, the classical view that muscle is unidirectionally dominant over bone via mechanical loading is overly simplistic. Indeed, recent studies indicate a role for neuronal regulation of not only muscle but also bone metabolism, bone signaling pathways like receptor activator of nuclear factor kappa-B ligand (RANKL) implicated in muscle biology, myokines affecting bone and possible bone-to-muscle communication. Moreover, pharmacological strategies inducing isolated myocyte hypertrophy may not translate into increased muscle power because tendons, connective tissue, neurons and energy metabolism need to adapt as well. We aim here to critically review key musculoskeletal molecular pathways involved in mechanoregulation and their effect on the bone-muscle unit as a whole, as well as preclinical and emerging clinical evidence regarding the effects of sarcopenia therapies on osteoporosis and vice versa.
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Affiliation(s)
- Michaël R Laurent
- Gerontology and Geriatrics, Department of Clinical and Experimental Medicine, KU Leuven, 3000 Leuven, Belgium; Laboratory of Molecular Endocrinology, Department of Cellular and Molecular Medicine, KU Leuven, 3000 Leuven, Belgium; Centre for Metabolic Bone Diseases, University Hospitals Leuven, 3000 Leuven, Belgium.
| | - Vanessa Dubois
- Laboratory of Molecular Endocrinology, Department of Cellular and Molecular Medicine, KU Leuven, 3000 Leuven, Belgium
| | - Frank Claessens
- Laboratory of Molecular Endocrinology, Department of Cellular and Molecular Medicine, KU Leuven, 3000 Leuven, Belgium
| | - Sabine M P Verschueren
- Research Group for Musculoskeletal Rehabilitation, Department of Rehabilitation Science, KU Leuven, 3000 Leuven, Belgium
| | - Dirk Vanderschueren
- Clinical and Experimental Endocrinology, Department of Clinical and Experimental Medicine, KU Leuven, 3000 Leuven, Belgium
| | - Evelien Gielen
- Gerontology and Geriatrics, Department of Clinical and Experimental Medicine, KU Leuven, 3000 Leuven, Belgium; Centre for Metabolic Bone Diseases, University Hospitals Leuven, 3000 Leuven, Belgium
| | - Ferran Jardí
- Clinical and Experimental Endocrinology, Department of Clinical and Experimental Medicine, KU Leuven, 3000 Leuven, Belgium
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Kim YJ, Tamadon A, Park HT, Kim H, Ku SY. The role of sex steroid hormones in the pathophysiology and treatment of sarcopenia. Osteoporos Sarcopenia 2016; 2:140-155. [PMID: 30775480 PMCID: PMC6372754 DOI: 10.1016/j.afos.2016.06.002] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/18/2016] [Revised: 06/09/2016] [Accepted: 06/17/2016] [Indexed: 12/18/2022] Open
Abstract
Sex steroids influence the maintenance and growth of muscles. Decline in androgens, estrogens and progesterone by aging leads to the loss of muscular function and mass, sarcopenia. These steroid hormones can interact with different signaling pathways through their receptors. To date, sex steroid hormone receptors and their exact roles are not completely defined in skeletal and smooth muscles. Although numerous studies focused on the effects of sex steroid hormones on different types of cells, still many unexplained molecular mechanisms in both skeletal and smooth muscle cells remain to be investigated. In this paper, many different molecular mechanisms that are activated or inhibited by sex steroids and those that influence the growth, proliferation, and differentiation of skeletal and smooth muscle cells are reviewed. Also, the similarities of cellular and molecular pathways of androgens, estrogens and progesterone in both skeletal and smooth muscle cells are highlighted. The reviewed signaling pathways and participating molecules can be targeted in the future development of novel therapeutics.
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Affiliation(s)
- Yong Jin Kim
- Department of Obstetrics and Gynecology, Korea University Guro Hospital, South Korea
| | - Amin Tamadon
- Department of Obstetrics and Gynecology, College of Medicine, Seoul National University, Seoul, South Korea
| | - Hyun Tae Park
- Department of Obstetrics and Gynecology, Korea University Anam Hospital, Korea University College of Medicine, South Korea
| | - Hoon Kim
- Department of Obstetrics and Gynecology, College of Medicine, Seoul National University, Seoul, South Korea
| | - Seung-Yup Ku
- Department of Obstetrics and Gynecology, College of Medicine, Seoul National University, Seoul, South Korea
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Rana K, Chiu MWS, Russell PK, Skinner JP, Lee NKL, Fam BC, Zajac JD, MacLean HE. Muscle-specific androgen receptor deletion shows limited actions in myoblasts but not in myofibers in different muscles in vivo. J Mol Endocrinol 2016; 57:125-38. [PMID: 27402875 DOI: 10.1530/jme-15-0320] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Accepted: 07/04/2016] [Indexed: 11/08/2022]
Abstract
The aim of this study was to investigate the direct muscle cell-mediated actions of androgens by comparing two different mouse lines. The cre-loxP system was used to delete the DNA-binding activity of the androgen receptor (AR) in mature myofibers (MCK mAR(ΔZF2)) in one model and the DNA-binding activity of the AR in both proliferating myoblasts and myofibers (α-actin mAR(ΔZF2)) in another model. We found that hind-limb muscle mass was normal in MCK mAR(ΔZF2) mice and that relative mass of only some hind-limb muscles was reduced in α-actin mAR(ΔZF2) mice. This suggests that myoblasts and myofibers are not the major cellular targets mediating the anabolic actions of androgens on male muscle during growth and development. Levator ani muscle mass was decreased in both mouse lines, demonstrating that there is a myofiber-specific effect in this unique androgen-dependent muscle. We found that the pattern of expression of genes including c-myc, Fzd4 and Igf2 is associated with androgen-dependent changes in muscle mass; therefore, these genes are likely to be mediators of anabolic actions of androgens. Further research is required to identify the major targets of androgen actions in muscle, which are likely to include indirect actions via other tissues.
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Affiliation(s)
- Kesha Rana
- Department of MedicineUniversity of Melbourne, Austin Health, Heidelberg, Victoria, Australia
| | - Maria W S Chiu
- Department of MedicineUniversity of Melbourne, Austin Health, Heidelberg, Victoria, Australia
| | - Patricia K Russell
- Department of MedicineUniversity of Melbourne, Austin Health, Heidelberg, Victoria, Australia
| | - Jarrod P Skinner
- Department of MedicineUniversity of Melbourne, Austin Health, Heidelberg, Victoria, Australia
| | - Nicole K L Lee
- Department of MedicineUniversity of Melbourne, Austin Health, Heidelberg, Victoria, Australia
| | - Barbara C Fam
- Department of MedicineUniversity of Melbourne, Austin Health, Heidelberg, Victoria, Australia
| | - Jeffrey D Zajac
- Department of MedicineUniversity of Melbourne, Austin Health, Heidelberg, Victoria, Australia
| | - Helen E MacLean
- Department of MedicineUniversity of Melbourne, Austin Health, Heidelberg, Victoria, Australia
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Dubois V, Laurent MR, Jardi F, Antonio L, Lemaire K, Goyvaerts L, Deldicque L, Carmeliet G, Decallonne B, Vanderschueren D, Claessens F. Androgen Deficiency Exacerbates High-Fat Diet-Induced Metabolic Alterations in Male Mice. Endocrinology 2016; 157:648-65. [PMID: 26562264 DOI: 10.1210/en.2015-1713] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Androgen deficiency is associated with obesity, metabolic syndrome, and type 2 diabetes mellitus in men, but the mechanisms behind these associations remain unclear. In this study, we investigated the combined effects of androgen deficiency and high-fat diet (HFD) on body composition and glucose homeostasis in C57BL/6J male mice. Two models of androgen deficiency were used: orchidectomy (ORX) and androgen receptor knockout mice. Both models displayed higher adiposity and serum leptin levels upon HFD, whereas no differences were seen on a regular diet. Fat accumulation in HFD ORX animals was accompanied by increased sedentary behavior and occurred in spite of reduced food intake. HFD ORX mice showed white adipocyte hypertrophy, correlated with decreased mitochondrial content but not function as well as increased lipogenesis and decreased lipolysis suggested by the up-regulation of fatty acid synthase and the down-regulation of hormone-sensitive lipase. Both ORX and androgen receptor knockout exacerbated HFD-induced glucose intolerance by impairing insulin action in liver and skeletal muscle, as evidenced by the increased triglyceride and decreased glycogen content in these tissues. In addition, serum IL-1β levels were elevated, and pancreatic insulin secretion was impaired after ORX. Testosterone but not dihydrotestosterone supplementation restored the castration effects on body composition and glucose homeostasis. We conclude that sex steroid deficiency in combination with HFD exacerbates adiposity, insulin resistance, and β-cell failure in 2 preclinical male mouse models. Our findings stress the importance of a healthy diet in a clinical context of androgen deficiency and may have implications for the prevention of metabolic alterations in hypogonadal men.
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Affiliation(s)
- Vanessa Dubois
- Molecular Endocrinology Laboratory (V.D., M.R.L., L.A., F.C.), Department of Cellular and Molecular Medicine, KU Leuven, 3000 Leuven, Belgium; Gerontology and Geriatrics (M.R.L.), KU Leuven, 3000 Leuven, Belgium; Clinical and Experimental Endocrinology (F.J., L.A., G.C., B.D., D.V.), Department of Clinical and Experimental Medicine, KU Leuven, 3000 Leuven, Belgium; Gene Expression Unit (K.L., L.G.), Department of Cellular and Molecular Medicine, KU Leuven, 3000 Leuven, Belgium; Exercise Physiology Research Group (L.D.), Department of Kinesiology, KU Leuven, 3000 Leuven, Belgium; and Institute of Neuroscience (L.D.), Université Catholique de Louvain, 1348 Louvain-la-Neuve, Belgium
| | - Michaël R Laurent
- Molecular Endocrinology Laboratory (V.D., M.R.L., L.A., F.C.), Department of Cellular and Molecular Medicine, KU Leuven, 3000 Leuven, Belgium; Gerontology and Geriatrics (M.R.L.), KU Leuven, 3000 Leuven, Belgium; Clinical and Experimental Endocrinology (F.J., L.A., G.C., B.D., D.V.), Department of Clinical and Experimental Medicine, KU Leuven, 3000 Leuven, Belgium; Gene Expression Unit (K.L., L.G.), Department of Cellular and Molecular Medicine, KU Leuven, 3000 Leuven, Belgium; Exercise Physiology Research Group (L.D.), Department of Kinesiology, KU Leuven, 3000 Leuven, Belgium; and Institute of Neuroscience (L.D.), Université Catholique de Louvain, 1348 Louvain-la-Neuve, Belgium
| | - Ferran Jardi
- Molecular Endocrinology Laboratory (V.D., M.R.L., L.A., F.C.), Department of Cellular and Molecular Medicine, KU Leuven, 3000 Leuven, Belgium; Gerontology and Geriatrics (M.R.L.), KU Leuven, 3000 Leuven, Belgium; Clinical and Experimental Endocrinology (F.J., L.A., G.C., B.D., D.V.), Department of Clinical and Experimental Medicine, KU Leuven, 3000 Leuven, Belgium; Gene Expression Unit (K.L., L.G.), Department of Cellular and Molecular Medicine, KU Leuven, 3000 Leuven, Belgium; Exercise Physiology Research Group (L.D.), Department of Kinesiology, KU Leuven, 3000 Leuven, Belgium; and Institute of Neuroscience (L.D.), Université Catholique de Louvain, 1348 Louvain-la-Neuve, Belgium
| | - Leen Antonio
- Molecular Endocrinology Laboratory (V.D., M.R.L., L.A., F.C.), Department of Cellular and Molecular Medicine, KU Leuven, 3000 Leuven, Belgium; Gerontology and Geriatrics (M.R.L.), KU Leuven, 3000 Leuven, Belgium; Clinical and Experimental Endocrinology (F.J., L.A., G.C., B.D., D.V.), Department of Clinical and Experimental Medicine, KU Leuven, 3000 Leuven, Belgium; Gene Expression Unit (K.L., L.G.), Department of Cellular and Molecular Medicine, KU Leuven, 3000 Leuven, Belgium; Exercise Physiology Research Group (L.D.), Department of Kinesiology, KU Leuven, 3000 Leuven, Belgium; and Institute of Neuroscience (L.D.), Université Catholique de Louvain, 1348 Louvain-la-Neuve, Belgium
| | - Katleen Lemaire
- Molecular Endocrinology Laboratory (V.D., M.R.L., L.A., F.C.), Department of Cellular and Molecular Medicine, KU Leuven, 3000 Leuven, Belgium; Gerontology and Geriatrics (M.R.L.), KU Leuven, 3000 Leuven, Belgium; Clinical and Experimental Endocrinology (F.J., L.A., G.C., B.D., D.V.), Department of Clinical and Experimental Medicine, KU Leuven, 3000 Leuven, Belgium; Gene Expression Unit (K.L., L.G.), Department of Cellular and Molecular Medicine, KU Leuven, 3000 Leuven, Belgium; Exercise Physiology Research Group (L.D.), Department of Kinesiology, KU Leuven, 3000 Leuven, Belgium; and Institute of Neuroscience (L.D.), Université Catholique de Louvain, 1348 Louvain-la-Neuve, Belgium
| | - Lotte Goyvaerts
- Molecular Endocrinology Laboratory (V.D., M.R.L., L.A., F.C.), Department of Cellular and Molecular Medicine, KU Leuven, 3000 Leuven, Belgium; Gerontology and Geriatrics (M.R.L.), KU Leuven, 3000 Leuven, Belgium; Clinical and Experimental Endocrinology (F.J., L.A., G.C., B.D., D.V.), Department of Clinical and Experimental Medicine, KU Leuven, 3000 Leuven, Belgium; Gene Expression Unit (K.L., L.G.), Department of Cellular and Molecular Medicine, KU Leuven, 3000 Leuven, Belgium; Exercise Physiology Research Group (L.D.), Department of Kinesiology, KU Leuven, 3000 Leuven, Belgium; and Institute of Neuroscience (L.D.), Université Catholique de Louvain, 1348 Louvain-la-Neuve, Belgium
| | - Louise Deldicque
- Molecular Endocrinology Laboratory (V.D., M.R.L., L.A., F.C.), Department of Cellular and Molecular Medicine, KU Leuven, 3000 Leuven, Belgium; Gerontology and Geriatrics (M.R.L.), KU Leuven, 3000 Leuven, Belgium; Clinical and Experimental Endocrinology (F.J., L.A., G.C., B.D., D.V.), Department of Clinical and Experimental Medicine, KU Leuven, 3000 Leuven, Belgium; Gene Expression Unit (K.L., L.G.), Department of Cellular and Molecular Medicine, KU Leuven, 3000 Leuven, Belgium; Exercise Physiology Research Group (L.D.), Department of Kinesiology, KU Leuven, 3000 Leuven, Belgium; and Institute of Neuroscience (L.D.), Université Catholique de Louvain, 1348 Louvain-la-Neuve, Belgium
| | - Geert Carmeliet
- Molecular Endocrinology Laboratory (V.D., M.R.L., L.A., F.C.), Department of Cellular and Molecular Medicine, KU Leuven, 3000 Leuven, Belgium; Gerontology and Geriatrics (M.R.L.), KU Leuven, 3000 Leuven, Belgium; Clinical and Experimental Endocrinology (F.J., L.A., G.C., B.D., D.V.), Department of Clinical and Experimental Medicine, KU Leuven, 3000 Leuven, Belgium; Gene Expression Unit (K.L., L.G.), Department of Cellular and Molecular Medicine, KU Leuven, 3000 Leuven, Belgium; Exercise Physiology Research Group (L.D.), Department of Kinesiology, KU Leuven, 3000 Leuven, Belgium; and Institute of Neuroscience (L.D.), Université Catholique de Louvain, 1348 Louvain-la-Neuve, Belgium
| | - Brigitte Decallonne
- Molecular Endocrinology Laboratory (V.D., M.R.L., L.A., F.C.), Department of Cellular and Molecular Medicine, KU Leuven, 3000 Leuven, Belgium; Gerontology and Geriatrics (M.R.L.), KU Leuven, 3000 Leuven, Belgium; Clinical and Experimental Endocrinology (F.J., L.A., G.C., B.D., D.V.), Department of Clinical and Experimental Medicine, KU Leuven, 3000 Leuven, Belgium; Gene Expression Unit (K.L., L.G.), Department of Cellular and Molecular Medicine, KU Leuven, 3000 Leuven, Belgium; Exercise Physiology Research Group (L.D.), Department of Kinesiology, KU Leuven, 3000 Leuven, Belgium; and Institute of Neuroscience (L.D.), Université Catholique de Louvain, 1348 Louvain-la-Neuve, Belgium
| | - Dirk Vanderschueren
- Molecular Endocrinology Laboratory (V.D., M.R.L., L.A., F.C.), Department of Cellular and Molecular Medicine, KU Leuven, 3000 Leuven, Belgium; Gerontology and Geriatrics (M.R.L.), KU Leuven, 3000 Leuven, Belgium; Clinical and Experimental Endocrinology (F.J., L.A., G.C., B.D., D.V.), Department of Clinical and Experimental Medicine, KU Leuven, 3000 Leuven, Belgium; Gene Expression Unit (K.L., L.G.), Department of Cellular and Molecular Medicine, KU Leuven, 3000 Leuven, Belgium; Exercise Physiology Research Group (L.D.), Department of Kinesiology, KU Leuven, 3000 Leuven, Belgium; and Institute of Neuroscience (L.D.), Université Catholique de Louvain, 1348 Louvain-la-Neuve, Belgium
| | - Frank Claessens
- Molecular Endocrinology Laboratory (V.D., M.R.L., L.A., F.C.), Department of Cellular and Molecular Medicine, KU Leuven, 3000 Leuven, Belgium; Gerontology and Geriatrics (M.R.L.), KU Leuven, 3000 Leuven, Belgium; Clinical and Experimental Endocrinology (F.J., L.A., G.C., B.D., D.V.), Department of Clinical and Experimental Medicine, KU Leuven, 3000 Leuven, Belgium; Gene Expression Unit (K.L., L.G.), Department of Cellular and Molecular Medicine, KU Leuven, 3000 Leuven, Belgium; Exercise Physiology Research Group (L.D.), Department of Kinesiology, KU Leuven, 3000 Leuven, Belgium; and Institute of Neuroscience (L.D.), Université Catholique de Louvain, 1348 Louvain-la-Neuve, Belgium
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71
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de Rooy C, Grossmann M, Zajac JD, Cheung AS. Targeting muscle signaling pathways to minimize adverse effects of androgen deprivation. Endocr Relat Cancer 2016; 23:R15-26. [PMID: 26432470 DOI: 10.1530/erc-15-0232] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 10/02/2015] [Indexed: 01/05/2023]
Abstract
Androgen deprivation therapy (ADT) is a highly effective treatment used in ∼30% of men with prostate cancer. Adverse effects of ADT on muscle are significant with consistent losses in muscle mass. However, effects of ADT on muscle strength and physical function, of most relevance to the patient, are less well understood. This is in part due to the fact that muscle effects of ADT at the cellular, genetic and protein level, critical to the understanding of the pathophysiology of sarcopenia, have come into focus only recently. This review highlights the complexity of androgen-dependent signaling in muscle with an emphasis on recent findings in the regulation of muscle growth and muscle atrophy pathways. Furthermore, the effects of ADT and testosterone on skeletal muscle histology, gene expression and protein transcription are discussed. A better mechanistic understanding of the regulation of muscle mass and function by androgens should not only pave the way for developing targeted promyogenic interventions for men with prostate cancer receiving ADT but also may have wider implications for age-associated sarcopenia in the general population.
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Affiliation(s)
- Casey de Rooy
- Department of MedicineUniversity of Melbourne, Heidelberg, Victoria, AustraliaDepartment of EndocrinologyAustin Health, Studley Road Heidelberg, Victoria, 3084, Australia
| | - Mathis Grossmann
- Department of MedicineUniversity of Melbourne, Heidelberg, Victoria, AustraliaDepartment of EndocrinologyAustin Health, Studley Road Heidelberg, Victoria, 3084, Australia Department of MedicineUniversity of Melbourne, Heidelberg, Victoria, AustraliaDepartment of EndocrinologyAustin Health, Studley Road Heidelberg, Victoria, 3084, Australia
| | - Jeffrey D Zajac
- Department of MedicineUniversity of Melbourne, Heidelberg, Victoria, AustraliaDepartment of EndocrinologyAustin Health, Studley Road Heidelberg, Victoria, 3084, Australia Department of MedicineUniversity of Melbourne, Heidelberg, Victoria, AustraliaDepartment of EndocrinologyAustin Health, Studley Road Heidelberg, Victoria, 3084, Australia
| | - Ada S Cheung
- Department of MedicineUniversity of Melbourne, Heidelberg, Victoria, AustraliaDepartment of EndocrinologyAustin Health, Studley Road Heidelberg, Victoria, 3084, Australia Department of MedicineUniversity of Melbourne, Heidelberg, Victoria, AustraliaDepartment of EndocrinologyAustin Health, Studley Road Heidelberg, Victoria, 3084, Australia
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72
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O'Hara L, Smith LB. Development and Characterization of Cell-Specific Androgen Receptor Knockout Mice. Methods Mol Biol 2016; 1443:219-248. [PMID: 27246343 DOI: 10.1007/978-1-4939-3724-0_14] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Conditional gene targeting has revolutionized molecular genetic analysis of nuclear receptor proteins, however development and analysis of such conditional knockouts is far from simple, with many caveats and pitfalls waiting to snare the novice or unprepared. In this chapter, we describe our experience of generating and analyzing mouse models with conditional ablation of the androgen receptor (AR) from tissues of the reproductive system and other organs. The guidance, suggestions, and protocols outlined in the chapter provide the key starting point for analyses of conditional-ARKO mice, completing them as described provides an excellent framework for further focussed project-specific analyses, and applies equally well to analysis of reproductive tissues from any mouse model generated through conditional gene targeting.
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Affiliation(s)
- Laura O'Hara
- MRC Centre for Reproductive Health, University of Edinburgh, Edinburgh, EH16 4TJ, UK
| | - Lee B Smith
- MRC Centre for Reproductive Health, University of Edinburgh, Edinburgh, EH16 4TJ, UK.
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73
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Dubois V, Simitsidellis I, Laurent MR, Jardi F, Saunders PTK, Vanderschueren D, Claessens F. Enobosarm (GTx-024) Modulates Adult Skeletal Muscle Mass Independently of the Androgen Receptor in the Satellite Cell Lineage. Endocrinology 2015; 156:4522-33. [PMID: 26393303 DOI: 10.1210/en.2015-1479] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Androgens increase skeletal muscle mass, but their clinical use is hampered by a lack of tissue selectivity and subsequent side effects. Selective androgen receptor modulators elicit muscle-anabolic effects while only sparingly affecting reproductive tissues. The selective androgen receptor modulator, GTx-024 (enobosarm), is being investigated for cancer cachexia, sarcopenia, and muscle wasting diseases. Here we investigate the role of muscle androgen receptor (AR) in the anabolic effect of GTx-024. In mice lacking AR in the satellite cell lineage (satARKO), the weight of the androgen-sensitive levator ani muscle was lower but was decreased further upon orchidectomy. GTx-024 was as effective as DHT in restoring levator ani weights to sham levels. Expression of the muscle-specific, androgen-responsive genes S-adenosylmethionine decarboxylase and myostatin was decreased by orchidectomy and restored by GTx-024 and DHT in control mice, whereas the expression was low and unaffected by androgen status in satARKO. In contrast, insulin-like growth factor 1Ea expression was not different between satARKO and control muscle, decreased upon castration, and was restored by DHT and GTx-024 in both genotypes. These data indicate that GTx-024 does not selectively modulate AR in the satellite cell lineage and that cells outside this lineage remain androgen responsive in satARKO muscle. Indeed, residual AR-positive cells were present in satARKO muscle, coexpressing the fibroblast-lineage marker vimentin. AR positive, muscle-resident fibroblasts could therefore be involved in the indirect effects of androgens on muscle. In conclusion, both DHT and GTx-024 target AR pathways in the satellite cell lineage, but cells outside this lineage also contribute to the anabolic effects of androgens.
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Affiliation(s)
- Vanessa Dubois
- Molecular Endocrinology Laboratory (V.D., M.R.L., F.C.), Department of Cellular and Molecular Medicine, Department of Gerontology and Geriatrics (M.R.L.), and Clinical and Experimental Endocrinology (F.J., D.V.), Department of Clinical and Experimental Medicine, KU Leuven, 3000 Leuven, Belgium; and Medical Research Council Centre for Inflammation Research (I.S., P.T.K.S.), University of Edinburgh, Edinburgh EH16 4SB, United Kingdom
| | - Ioannis Simitsidellis
- Molecular Endocrinology Laboratory (V.D., M.R.L., F.C.), Department of Cellular and Molecular Medicine, Department of Gerontology and Geriatrics (M.R.L.), and Clinical and Experimental Endocrinology (F.J., D.V.), Department of Clinical and Experimental Medicine, KU Leuven, 3000 Leuven, Belgium; and Medical Research Council Centre for Inflammation Research (I.S., P.T.K.S.), University of Edinburgh, Edinburgh EH16 4SB, United Kingdom
| | - Michaël R Laurent
- Molecular Endocrinology Laboratory (V.D., M.R.L., F.C.), Department of Cellular and Molecular Medicine, Department of Gerontology and Geriatrics (M.R.L.), and Clinical and Experimental Endocrinology (F.J., D.V.), Department of Clinical and Experimental Medicine, KU Leuven, 3000 Leuven, Belgium; and Medical Research Council Centre for Inflammation Research (I.S., P.T.K.S.), University of Edinburgh, Edinburgh EH16 4SB, United Kingdom
| | - Ferran Jardi
- Molecular Endocrinology Laboratory (V.D., M.R.L., F.C.), Department of Cellular and Molecular Medicine, Department of Gerontology and Geriatrics (M.R.L.), and Clinical and Experimental Endocrinology (F.J., D.V.), Department of Clinical and Experimental Medicine, KU Leuven, 3000 Leuven, Belgium; and Medical Research Council Centre for Inflammation Research (I.S., P.T.K.S.), University of Edinburgh, Edinburgh EH16 4SB, United Kingdom
| | - Philippa T K Saunders
- Molecular Endocrinology Laboratory (V.D., M.R.L., F.C.), Department of Cellular and Molecular Medicine, Department of Gerontology and Geriatrics (M.R.L.), and Clinical and Experimental Endocrinology (F.J., D.V.), Department of Clinical and Experimental Medicine, KU Leuven, 3000 Leuven, Belgium; and Medical Research Council Centre for Inflammation Research (I.S., P.T.K.S.), University of Edinburgh, Edinburgh EH16 4SB, United Kingdom
| | - Dirk Vanderschueren
- Molecular Endocrinology Laboratory (V.D., M.R.L., F.C.), Department of Cellular and Molecular Medicine, Department of Gerontology and Geriatrics (M.R.L.), and Clinical and Experimental Endocrinology (F.J., D.V.), Department of Clinical and Experimental Medicine, KU Leuven, 3000 Leuven, Belgium; and Medical Research Council Centre for Inflammation Research (I.S., P.T.K.S.), University of Edinburgh, Edinburgh EH16 4SB, United Kingdom
| | - Frank Claessens
- Molecular Endocrinology Laboratory (V.D., M.R.L., F.C.), Department of Cellular and Molecular Medicine, Department of Gerontology and Geriatrics (M.R.L.), and Clinical and Experimental Endocrinology (F.J., D.V.), Department of Clinical and Experimental Medicine, KU Leuven, 3000 Leuven, Belgium; and Medical Research Council Centre for Inflammation Research (I.S., P.T.K.S.), University of Edinburgh, Edinburgh EH16 4SB, United Kingdom
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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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Carson JA, Manolagas SC. Effects of sex steroids on bones and muscles: Similarities, parallels, and putative interactions in health and disease. Bone 2015; 80:67-78. [PMID: 26453497 PMCID: PMC4600533 DOI: 10.1016/j.bone.2015.04.015] [Citation(s) in RCA: 94] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Revised: 03/23/2015] [Accepted: 04/07/2015] [Indexed: 12/31/2022]
Abstract
Estrogens and androgens influence the growth and maintenance of bones and muscles and are responsible for their sexual dimorphism. A decline in their circulating levels leads to loss of mass and functional integrity in both tissues. In the article, we highlight the similarities of the molecular and cellular mechanisms of action of sex steroids in the two tissues; the commonality of a critical role of mechanical forces on tissue mass and function; emerging evidence for an interplay between mechanical forces and hormonal and growth factor signals in both bones and muscles; as well as the current state of evidence for or against a cross-talk between muscles and bone. In addition, we review evidence for the parallels in the development of osteoporosis and sarcopenia with advancing age and the potential common mechanisms responsible for the age-dependent involution of these two tissues. Lastly, we discuss the striking difference in the availability of several drug therapies for the prevention and treatment of osteoporosis, as compared to none for sarcopenia. This article is part of a Special Issue entitled "Muscle Bone Interactions".
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Affiliation(s)
- James A Carson
- Department of Exercise Science, Arnold School of Public Health, University of South Carolina, Columbia, SC 29208 USA
| | - Stavros C Manolagas
- Division of Endocrinology and Metabolism, Center for Osteoporosis and Metabolic Bone Diseases, University of Arkansas for Medical Sciences and the Central Arkansas Veterans Healthcare System, Little Rock, AR, USA.
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76
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Ma D, Gao P, Qian L, Wang Q, Cai C, Jiang S, Xiao G, Cui W. Over-Expression of Porcine Myostatin Missense Mutant Leads to A Gender Difference in Skeletal Muscle Growth between Transgenic Male and Female Mice. Int J Mol Sci 2015; 16:20020-32. [PMID: 26305245 PMCID: PMC4581338 DOI: 10.3390/ijms160820020] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2015] [Revised: 08/01/2015] [Accepted: 08/04/2015] [Indexed: 11/16/2022] Open
Abstract
Myostatin, a transforming growth factor-β family member, is a negative regulator of skeletal muscle development and growth. Piedmontese cattle breeds have a missense mutation, which results in a cysteine to tyrosine substitution in the mature myostatin protein (C313Y). This loss-of-function mutation in myostatin results in a double-muscled phenotype in cattle. Myostatin propeptide is an inhibitor of myostatin activity and is considered a potential agent to stimulate muscle growth in livestock. In this study, we generated transgenic mice overexpressing porcine myostatin missense mutant (pmMS), C313Y, and wild-type porcine myostatin propeptide (ppMS), respectively, to examine their effects on muscle growth in mice. Enhanced muscle growth was observed in both pmMS and ppMS transgenic female mice and also in ppMS transgenic male mice. However, there was no enhanced muscle growth observed in pmMS transgenic male mice. To explore why there is such a big difference in muscle growth between pmMS and ppMS transgenic male mice, the expression level of androgen receptor (AR) mutant AR45 was measured by Western blot. Results indicated that AR45 expression significantly increased in pmMS transgenic male mice while it decreased dramatically in ppMS transgenic male mice. Our data demonstrate that both pmMS and ppMS act as myostatin inhibitors in the regulation of muscle growth, but the effect of pmMS in male mice is reversed by an increased AR45 expression. These results provide useful insight and basic theory to future studies on improving pork quality by genetically manipulating myostatin expression or by regulating myostatin activity.
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Affiliation(s)
- Dezun Ma
- State Key Laboratory for Animal Nutrition, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China.
| | - Pengfei Gao
- State Key Laboratory for Animal Nutrition, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China.
| | - Lili Qian
- College of Biological Sciences, China Agricultural University, Beijing 100193, China.
| | - Qingqing Wang
- State Key Laboratory for Animal Nutrition, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China.
| | - Chunbo Cai
- College of Biological Sciences, China Agricultural University, Beijing 100193, China.
| | - Shengwang Jiang
- State Key Laboratory for Animal Nutrition, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China.
| | - Gaojun Xiao
- State Key Laboratory for Animal Nutrition, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China.
| | - Wentao Cui
- State Key Laboratory for Animal Nutrition, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China.
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77
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Biressi S, Gopinath SD. The quasi-parallel lives of satellite cells and atrophying muscle. Front Aging Neurosci 2015; 7:140. [PMID: 26257645 PMCID: PMC4510774 DOI: 10.3389/fnagi.2015.00140] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2015] [Accepted: 07/06/2015] [Indexed: 12/25/2022] Open
Abstract
Skeletal muscle atrophy or wasting accompanies various chronic illnesses and the aging process, thereby reducing muscle function. One of the most important components contributing to effective muscle repair in postnatal organisms, the satellite cells (SCs), have recently become the focus of several studies examining factors participating in the atrophic process. We critically examine here the experimental evidence linking SC function with muscle loss in connection with various diseases as well as aging, and in the subsequent recovery process. Several recent reports have investigated the changes in SCs in terms of their differentiation and proliferative capacity in response to various atrophic stimuli. In this regard, we review the molecular changes within SCs that contribute to their dysfunctional status in atrophy, with the intention of shedding light on novel potential pharmacological targets to counteract the loss of muscle mass.
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Affiliation(s)
- Stefano Biressi
- Dulbecco Telethon Institute and Centre for Integrative Biology (CIBIO), University of TrentoTrento, Italy
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78
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Laurent MR, Gielen E, Vanderschueren D. Estrogens, the be-all and end-all of male hypogonadal bone loss? Osteoporos Int 2015; 26:29-33. [PMID: 25377497 DOI: 10.1007/s00198-014-2865-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/13/2014] [Accepted: 08/19/2014] [Indexed: 10/24/2022]
Affiliation(s)
- M R Laurent
- Gerontology and Geriatrics, Department of Clinical and Experimental Medicine, KU Leuven, Leuven, Belgium,
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79
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Vanderschueren D, Laurent MR, Claessens F, Gielen E, Lagerquist MK, Vandenput L, Börjesson AE, Ohlsson C. Sex steroid actions in male bone. Endocr Rev 2014; 35:906-60. [PMID: 25202834 PMCID: PMC4234776 DOI: 10.1210/er.2014-1024] [Citation(s) in RCA: 184] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Sex steroids are chief regulators of gender differences in the skeleton, and male gender is one of the strongest protective factors against osteoporotic fractures. This advantage in bone strength relies mainly on greater cortical bone expansion during pubertal peak bone mass acquisition and superior skeletal maintenance during aging. During both these phases, estrogens acting via estrogen receptor-α in osteoblast lineage cells are crucial for male cortical and trabecular bone, as evident from conditional genetic mouse models, epidemiological studies, rare genetic conditions, genome-wide meta-analyses, and recent interventional trials. Genetic mouse models have also demonstrated a direct role for androgens independent of aromatization on trabecular bone via the androgen receptor in osteoblasts and osteocytes, although the target cell for their key effects on periosteal bone formation remains elusive. Low serum estradiol predicts incident fractures, but the highest risk occurs in men with additionally low T and high SHBG. Still, the possible clinical utility of serum sex steroids for fracture prediction is unknown. It is likely that sex steroid actions on male bone metabolism rely also on extraskeletal mechanisms and cross talk with other signaling pathways. We propose that estrogens influence fracture risk in aging men via direct effects on bone, whereas androgens exert an additional antifracture effect mainly via extraskeletal parameters such as muscle mass and propensity to fall. Given the demographic trends of increased longevity and consequent rise of osteoporosis, an increased understanding of how sex steroids influence male bone health remains a high research priority.
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Affiliation(s)
- Dirk Vanderschueren
- Clinical and Experimental Endocrinology (D.V.) and Gerontology and Geriatrics (M.R.L., E.G.), Department of Clinical and Experimental Medicine; Laboratory of Molecular Endocrinology, Department of Cellular and Molecular Medicine (M.R.L., F.C.); and Centre for Metabolic Bone Diseases (D.V., M.R.L., E.G.), KU Leuven, B-3000 Leuven, Belgium; and Center for Bone and Arthritis Research (M.K.L., L.V., A.E.B., C.O.), Department of Internal Medicine and Clinical Nutrition, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, 413 45 Gothenburg, Sweden
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80
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Rodriguez J, Vernus B, Chelh I, Cassar-Malek I, Gabillard JC, Hadj Sassi A, Seiliez I, Picard B, Bonnieu A. Myostatin and the skeletal muscle atrophy and hypertrophy signaling pathways. Cell Mol Life Sci 2014; 71:4361-71. [PMID: 25080109 PMCID: PMC11113773 DOI: 10.1007/s00018-014-1689-x] [Citation(s) in RCA: 255] [Impact Index Per Article: 25.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2014] [Revised: 07/16/2014] [Accepted: 07/17/2014] [Indexed: 12/16/2022]
Abstract
Myostatin, a member of the transforming growth factor-β superfamily, is a potent negative regulator of skeletal muscle growth and is conserved in many species, from rodents to humans. Myostatin inactivation can induce skeletal muscle hypertrophy, while its overexpression or systemic administration causes muscle atrophy. As it represents a potential target for stimulating muscle growth and/or preventing muscle wasting, myostatin regulation and functions in the control of muscle mass have been extensively studied. A wealth of data strongly suggests that alterations in skeletal muscle mass are associated with dysregulation in myostatin expression. Moreover, myostatin plays a central role in integrating/mediating anabolic and catabolic responses. Myostatin negatively regulates the activity of the Akt pathway, which promotes protein synthesis, and increases the activity of the ubiquitin-proteasome system to induce atrophy. Several new studies have brought new information on how myostatin may affect both ribosomal biogenesis and translation efficiency of specific mRNA subclasses. In addition, although myostatin has been identified as a modulator of the major catabolic pathways, including the ubiquitin-proteasome and the autophagy-lysosome systems, the underlying mechanisms are only partially understood. The goal of this review is to highlight outstanding questions about myostatin-mediated regulation of the anabolic and catabolic signaling pathways in skeletal muscle. Particular emphasis has been placed on (1) the cross-regulation between myostatin, the growth-promoting pathways and the proteolytic systems; (2) how myostatin inhibition leads to muscle hypertrophy; and (3) the regulation of translation by myostatin.
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Affiliation(s)
- J. Rodriguez
- INRA, UMR866 Dynamique Musculaire Et Métabolisme, Université Montpellier 1, Université Montpellier 2, 2 Place Viala, 34060 Montpellier, France
| | - B. Vernus
- INRA, UMR866 Dynamique Musculaire Et Métabolisme, Université Montpellier 1, Université Montpellier 2, 2 Place Viala, 34060 Montpellier, France
| | - I. Chelh
- INRA, VetAgro Sup, UMR1213 Herbivores, 63122 Saint-Genès-Champanelle, France
| | - I. Cassar-Malek
- INRA, VetAgro Sup, UMR1213 Herbivores, 63122 Saint-Genès-Champanelle, France
| | - J. C. Gabillard
- INRA, UR1037, Fish Physiology and Genomics, Campus de Beaulieu, 35000 Rennes, France
| | - A. Hadj Sassi
- INRA-USC2009, Université Bordeaux 1, Avenue des Facultés, 33405 Talence, France
| | - I. Seiliez
- INRA, UR1067 Nutrition, Métabolisme, Aquaculture, 64310 Saint-Pée-sur-Nivelle, France
| | - B. Picard
- INRA, VetAgro Sup, UMR1213 Herbivores, 63122 Saint-Genès-Champanelle, France
| | - A. Bonnieu
- INRA, UMR866 Dynamique Musculaire Et Métabolisme, Université Montpellier 1, Université Montpellier 2, 2 Place Viala, 34060 Montpellier, France
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