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Venkatesh VS, Nie T, Golub S, Stok KS, Hemmatian H, Desai R, Handelsman DJ, Zajac JD, Grossmann M, Davey RA. High circulating concentrations of estradiol are anabolic for bone mass and strength in an adult male to female transgender mouse model. Bone 2024; 186:117143. [PMID: 38866125 DOI: 10.1016/j.bone.2024.117143] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/25/2024] [Revised: 05/29/2024] [Accepted: 05/31/2024] [Indexed: 06/14/2024]
Abstract
The effects of gender affirming hormone therapy (GAHT) on bone microarchitecture and fracture risk in adult transgender women is unclear. To investigate the concept that skeletal integrity and strength in trans women may be improved by treatment with a higher dose of GAHT than commonly prescribed, we treated adult male mice with a sustained, high dose of estradiol. Adult male mice at 16 weeks of age were administered ~1.3 mg estradiol by silastic implant, implanted intraperitoneally, for 12 weeks. Controls included vehicle treated intact females and males. High-dose estradiol treatment in males stimulated the endocortical deposition of bone at the femoral mid-diaphysis, increasing cortical thickness and bone area. This led to higher stiffness, maximum force, and the work required to fracture the bone compared to male controls, while post-yield displacement was unaffected. Assessment of the material properties of the bone showed an increase in both elastic modulus and ultimate stress in the estradiol treated males. Treatment of male mice with high dose estradiol was also anabolic for trabecular bone, markedly increasing trabecular bone volume, number and thickness in the distal metaphysis which was accompanied by an increase in the histomorphometric markers of bone remodelling, mineralizing surface/bone surface, bone formation rate and osteoclast number. In conclusion, a high dose of estradiol is anabolic for cortical and trabecular bone in a male to female transgender mouse model, increasing both stiffness and strength. These findings suggest that increasing the current dose of GAHT administered to trans women, while considering other potential adverse effects, may be beneficial to preserving their bone microstructure and strength.
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Affiliation(s)
- Varun S Venkatesh
- Department of Medicine, Austin Health, University of Melbourne, Heidelberg, Victoria 3084, Australia; Department of Endocrinology, Austin Health, Heidelberg, Victoria, Australia.
| | - Tian Nie
- Department of Medicine, Austin Health, University of Melbourne, Heidelberg, Victoria 3084, Australia.
| | - Suzanne Golub
- Department of Medicine, Austin Health, University of Melbourne, Heidelberg, Victoria 3084, Australia.
| | - Kathryn S Stok
- Department of Biomedical Engineering, University of Melbourne, Parkville, Victoria 3010, Australia.
| | - Haniyeh Hemmatian
- Department of Medicine, Austin Health, University of Melbourne, Heidelberg, Victoria 3084, Australia.
| | - Reena Desai
- ANZAC Research Institute, University of Sydney and Andrology, Concord Repatriation General Hospital, Concord, New South Wales 2137, Australia.
| | - David J Handelsman
- ANZAC Research Institute, University of Sydney and Andrology, Concord Repatriation General Hospital, Concord, New South Wales 2137, Australia.
| | - Jeffrey D Zajac
- Department of Medicine, Austin Health, University of Melbourne, Heidelberg, Victoria 3084, Australia.
| | - Mathis Grossmann
- Department of Medicine, Austin Health, University of Melbourne, Heidelberg, Victoria 3084, Australia; Department of Endocrinology, Austin Health, Heidelberg, Victoria, Australia.
| | - Rachel A Davey
- Department of Medicine, Austin Health, University of Melbourne, Heidelberg, Victoria 3084, Australia.
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2
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Grigoryan S, Clines GA. Hormonal Control of Bone Architecture Throughout the Lifespan: Implications for Fracture Prediction and Prevention. Endocr Pract 2024; 30:687-694. [PMID: 38631489 DOI: 10.1016/j.eprac.2024.04.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/27/2024] [Revised: 03/31/2024] [Accepted: 04/09/2024] [Indexed: 04/19/2024]
Abstract
BACKGROUND Skeletal modeling in childhood and adolescence and continuous remodeling throughout the lifespan are designed to adapt to a changing environment and resist external forces and fractures. The flux of sex steroids in men and women, beginning from fetal development and evolving through infancy, childhood, puberty, young adulthood, peri/menopause transition, and postmenopause, is critical for bone size, peak bone mass, and fracture resistance. OBJECTIVE This review will highlight how changes in sex steroids throughout the lifespan affect bone cells and the consequence of these changes on bone architecture and strength. METHODS Literature review and discussion. RESULTS The contributions of estrogen and testosterone on skeletal development have been difficult to study due to the reciprocal and intertwining contributions of one on the other. Although orchiectomy in men renders circulating testosterone absent, circulating estrogen also declines due to testosterone being the substrate for estradiol. The discovery of men with absent estradiol or resistance to estrogen and the study of mouse models led to the understanding that estrogen has a larger direct role in skeletal development and maintenance in men and women. The mechanistic reason for larger bone size in men is incompletely understood but related to indirect effects of testosterone on the skeleton, such as higher muscle mass leading to larger mechanical loading. Declines in sex steroids during menopause in women and androgen deprivation therapies in men have profound and negative effects on the skeleton. Therapies to prevent such bone loss are available, but how such therapies can be tailored based on bone size and architecture remains an area of investigation. CONCLUSION In this review, the elegant interplay and contribution of sex steroids on bone architecture in men and women throughout the lifespan is described.
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Affiliation(s)
- Seda Grigoryan
- Division of Metabolism, Endocrinology & Diabetes, Department of Internal Medicine, University of Michigan School of Medicine, Ann Arbor, Michigan
| | - Gregory A Clines
- Division of Metabolism, Endocrinology & Diabetes, Department of Internal Medicine, University of Michigan School of Medicine, Ann Arbor, Michigan; Endocrinology Section, Veterans Affairs Medical Center, Ann Arbor, Michigan.
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3
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Kalyanaraman H, Casteel DE, China SP, Zhuang S, Boss GR, Pilz RB. A plasma membrane-associated form of the androgen receptor enhances nuclear androgen signaling in osteoblasts and prostate cancer cells. Sci Signal 2024; 17:eadi7861. [PMID: 38289986 PMCID: PMC10916501 DOI: 10.1126/scisignal.adi7861] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Accepted: 01/09/2024] [Indexed: 02/01/2024]
Abstract
Androgen binding to the androgen receptor (AR) in the cytoplasm induces the AR to translocate to the nucleus, where it regulates the expression of target genes. Here, we found that androgens rapidly activated a plasma membrane-associated signaling node that enhanced nuclear AR functions. In murine primary osteoblasts, dihydrotestosterone (DHT) binding to a membrane-associated form of AR stimulated plasma membrane-associated protein kinase G type 2 (PKG2), leading to the activation of multiple kinases, including ERK. Phosphorylation of AR at Ser515 by ERK increased the nuclear accumulation and binding of AR to the promoter of Ctnnb1, which encodes the transcription factor β-catenin. In male mouse osteoblasts and human prostate cancer cells, DHT induced the expression of Ctnnb1 and CTNN1B, respectively, as well as β-catenin target genes, stimulating the proliferation, survival, and differentiation of osteoblasts and the proliferation of prostate cancer cells in a PKG2-dependent fashion. Because β-catenin is a master regulator of skeletal homeostasis, these results explain the reported male-specific osteoporotic phenotype of mice lacking PKG2 in osteoblasts and imply that PKG2-dependent AR signaling is essential for maintaining bone mass in vivo. Our results suggest that widely used pharmacological PKG activators, such as sildenafil, could be beneficial for male and estrogen-deficient female patients with osteoporosis but detrimental in patients with prostate cancer.
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Affiliation(s)
- Hema Kalyanaraman
- Department of Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Darren E. Casteel
- Department of Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Shyamsundar Pal China
- Department of Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Shunhui Zhuang
- Department of Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Gerry R. Boss
- Department of Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Renate B. Pilz
- Department of Medicine, University of California, San Diego, La Jolla, CA 92093, USA
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4
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Nie T, Venkatesh VS, Golub S, Stok KS, Hemmatian H, Desai R, Handelsman DJ, Zajac JD, Grossmann M, Davey RA. Estradiol increases cortical and trabecular bone accrual and bone strength in an adolescent male-to-female mouse model of gender-affirming hormone therapy. Bone Res 2024; 12:1. [PMID: 38212599 PMCID: PMC10784310 DOI: 10.1038/s41413-023-00308-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Revised: 11/28/2023] [Accepted: 12/05/2023] [Indexed: 01/13/2024] Open
Abstract
The effects of gender-affirming hormone therapy on the skeletal integrity and fracture risk in transitioning adolescent trans girls are unknown. To address this knowledge gap, we developed a mouse model to simulate male-to-female transition in human adolescents in whom puberty is first arrested by using gonadotrophin-releasing hormone analogs with subsequent estradiol treatment. Puberty was suppressed by orchidectomy in male mice at 5 weeks of age. At 3 weeks post-surgery, male-to-female mice were treated with a high dose of estradiol (~0.85 mg) by intraperitoneal silastic implantation for 12 weeks. Controls included intact and orchidectomized males at 3 weeks post-surgery, vehicle-treated intact males, intact females and orchidectomized males at 12 weeks post-treatment. Compared to male controls, orchidectomized males exhibited decreased peak bone mass accrual and a decreased maximal force the bone could withstand prior to fracture. Estradiol treatment in orchidectomized male-to-female mice compared to mice in all control groups was associated with an increased cortical thickness in the mid-diaphysis, while the periosteal circumference increased to a level that was intermediate between intact male and female controls, resulting in increased maximal force and stiffness. In trabecular bone, estradiol treatment increased newly formed trabeculae arising from the growth plate as well as mineralizing surface/bone surface and bone formation rate, consistent with the anabolic action of estradiol on osteoblast proliferation. These data support the concept that skeletal integrity can be preserved and that long-term fractures may be prevented in trans girls treated with GnRHa and a sufficiently high dose of GAHT. Further study is needed to identify an optimal dose of estradiol that protects the bone without adverse side effects.
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Affiliation(s)
- Tian Nie
- Department of Medicine, Austin Health, University of Melbourne, Heidelberg, VIC, 3084, Australia
| | - Varun S Venkatesh
- Department of Medicine, Austin Health, University of Melbourne, Heidelberg, VIC, 3084, Australia
| | - Suzanne Golub
- Department of Medicine, Austin Health, University of Melbourne, Heidelberg, VIC, 3084, Australia
| | - Kathryn S Stok
- Department of Biomedical Engineering, University of Melbourne, Parkville, VIC, 3010, Australia
| | - Haniyeh Hemmatian
- Department of Medicine, Austin Health, University of Melbourne, Heidelberg, VIC, 3084, Australia
| | - Reena Desai
- ANZAC Research Institute, University of Sydney and Andrology, Concord Repatriation General Hospital, Concord, NSW, 2137, Australia
| | - David J Handelsman
- ANZAC Research Institute, University of Sydney and Andrology, Concord Repatriation General Hospital, Concord, NSW, 2137, Australia
| | - Jeffrey D Zajac
- Department of Medicine, Austin Health, University of Melbourne, Heidelberg, VIC, 3084, Australia
| | - Mathis Grossmann
- Department of Medicine, Austin Health, University of Melbourne, Heidelberg, VIC, 3084, Australia
| | - Rachel A Davey
- Department of Medicine, Austin Health, University of Melbourne, Heidelberg, VIC, 3084, Australia.
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5
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Venkatesh VS, Nie T, Zajac JD, Grossmann M, Davey RA. The Utility of Preclinical Models in Understanding the Bone Health of Transgender Individuals Undergoing Gender-Affirming Hormone Therapy. Curr Osteoporos Rep 2023; 21:825-841. [PMID: 37707757 PMCID: PMC10724092 DOI: 10.1007/s11914-023-00818-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 08/16/2023] [Indexed: 09/15/2023]
Abstract
PURPOSE OF REVIEW To summarise the evidence regarding the effects of gender-affirming hormone therapy (GAHT) on bone health in transgender people, to identify key knowledge gaps and how these gaps can be addressed using preclinical rodent models. RECENT FINDINGS Sex hormones play a critical role in bone physiology, yet there is a paucity of research regarding the effects of GAHT on bone microstructure and fracture risk in transgender individuals. The controlled clinical studies required to yield fracture data are unethical to conduct making clinically translatable preclinical research of the utmost importance. Novel genetic and surgical preclinical models have yielded significant mechanistic insight into the roles of sex steroids on skeletal integrity. Preclinical models of GAHT have the potential inform clinical approaches to preserve skeletal integrity and prevent fractures in transgender people undergoing GAHT. This review highlights the key considerations required to ensure the information gained from preclinical models of GAHT are informative.
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Affiliation(s)
- Varun S Venkatesh
- Department of Medicine, Austin Health, The University of Melbourne, Heidelberg, Victoria, 3084, Australia
| | - Tian Nie
- Department of Medicine, Austin Health, The University of Melbourne, Heidelberg, Victoria, 3084, Australia
| | - Jeffrey D Zajac
- Department of Medicine, Austin Health, The University of Melbourne, Heidelberg, Victoria, 3084, Australia
- Department of Endocrinology, Austin Health, Heidelberg, Victoria, 3084, Australia
| | - Mathis Grossmann
- Department of Medicine, Austin Health, The University of Melbourne, Heidelberg, Victoria, 3084, Australia
- Department of Endocrinology, Austin Health, Heidelberg, Victoria, 3084, Australia
| | - Rachel A Davey
- Department of Medicine, Austin Health, The University of Melbourne, Heidelberg, Victoria, 3084, Australia.
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6
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Rouge M, Legendre F, Elkhatib R, Delalande C, Cognié J, Reigner F, Barrière P, Deleuze S, Hanoux V, Galéra P, Bouraïma-Lelong H. Early Castration in Horses Does Not Impact Osteoarticular Metabolism. Int J Mol Sci 2023; 24:16778. [PMID: 38069100 PMCID: PMC10706761 DOI: 10.3390/ijms242316778] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Revised: 11/17/2023] [Accepted: 11/20/2023] [Indexed: 12/18/2023] Open
Abstract
The castration of stallions is traditionally performed after puberty, at around the age of 2 years old. No studies have focused on the effects of early castration on osteoarticular metabolism. Thus, we aimed to compare early castration (3 days after birth) with traditional castration (18 months of age) in horses. Testosterone and estradiol levels were monitored from birth to 33 months in both groups. We quantified the levels of biomarkers of cartilage and bone anabolism (CPII and N-MID) and catabolism (CTX-I and CTX-II), as well as of osteoarthritis (HA and COMP) and inflammation (IL-6 and PGE2). We observed a lack of parallelism between testosterone and estradiol synthesis after birth and during puberty in both groups. The extra-gonadal synthesis of steroids was observed around the 28-month mark, regardless of the castration age. We found the expression of estrogen receptor (ESR1) in cartilage and bone, whereas androgen receptor (AR) expression appeared to be restricted to bone. Nevertheless, with respect to osteoarticular metabolism, steroid hormone deprivation resulting from early castration had no discernable impact on the levels of biomarkers related to bone and cartilage metabolism, nor on those associated with OA and inflammation. Consequently, our research demonstrated that early castration does not disrupt bone and cartilage homeostasis.
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Affiliation(s)
- Marion Rouge
- Université de Caen-Normandie, OeReCa, 14000 Caen, France; (M.R.); (R.E.); (C.D.); (V.H.)
| | - Florence Legendre
- Université de Caen Normandie BIOTARGEN, 14000 Caen, France; (F.L.); (P.G.)
| | - Razan Elkhatib
- Université de Caen-Normandie, OeReCa, 14000 Caen, France; (M.R.); (R.E.); (C.D.); (V.H.)
| | - Christelle Delalande
- Université de Caen-Normandie, OeReCa, 14000 Caen, France; (M.R.); (R.E.); (C.D.); (V.H.)
| | - Juliette Cognié
- INRAE, Université de Tours, Centre de Recherche de Tours, UMR PRC, 37380 Nouzilly, France;
| | - Fabrice Reigner
- INRAE, Université de Tours, Centre de Recherche de Tours, UEPAO, 37380 Nouzilly, France; (F.R.); (P.B.)
| | - Philippe Barrière
- INRAE, Université de Tours, Centre de Recherche de Tours, UEPAO, 37380 Nouzilly, France; (F.R.); (P.B.)
| | | | - Vincent Hanoux
- Université de Caen-Normandie, OeReCa, 14000 Caen, France; (M.R.); (R.E.); (C.D.); (V.H.)
| | - Philippe Galéra
- Université de Caen Normandie BIOTARGEN, 14000 Caen, France; (F.L.); (P.G.)
| | - Hélène Bouraïma-Lelong
- Université de Caen-Normandie, OeReCa, 14000 Caen, France; (M.R.); (R.E.); (C.D.); (V.H.)
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7
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Xu X, Yang H, Bullock WA, Gallant MA, Ohlsson C, Bellido TM, Main RP. Osteocyte Estrogen Receptor β (Ot-ERβ) Regulates Bone Turnover and Skeletal Adaptive Response to Mechanical Loading Differently in Male and Female Growing and Adult Mice. J Bone Miner Res 2023; 38:186-197. [PMID: 36321245 PMCID: PMC10108310 DOI: 10.1002/jbmr.4731] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Revised: 10/15/2022] [Accepted: 10/29/2022] [Indexed: 11/06/2022]
Abstract
Age-related bone loss is a failure of balanced bone turnover and diminished skeletal mechanoadaptation. Estrogen receptors, ERα and ERβ, play critical roles in osteoprotective regulation activated by estrogen and mechanical signals. Previous studies mainly focused on ERα and showed that osteocyte-ERα (Ot-ERα) regulated trabecular, but not cortical bone, and played a minor role in load-induced cortical adaptation. However, the role of Ot-ERβ in bone mass regulation remains unrevealed. To address this issue, we characterized bone (re)modeling and gene expression in male and female mice with Ot-ERβ deletion (ERβ-dOT) and littermate control (LC) at 10 weeks (young) or 28 weeks (adult) of age, as well as their responses to in vivo tibial compressive loading. Increased cancellous bone mass appeared in the L4 vertebral body of young male ERβ-dOT mice. At the same time, femoral cortical bone gene expression showed signs consistent with elevated osteoblast and osteoclast activities (type-I collagen, Cat K, RANKL). Upregulated androgen receptor (AR) expression was observed in young male ERβ-dOT mice relative to LC, suggesting a compensatory effect of testosterone on male bone protection. In contrast, bone mass in L4 decreased in adult male ERβ-dOT mice, attributed to potentially increased bone resorption activity (Cat K) with no change in bone formation. There was no effect of ERβ-dOT on bone mass or gene expression in female mice. Sex-dependent regulation of Ot-ERβ also appeared in load-induced cortical responsiveness. Young female ERβ-dOT mice showed an enhanced tibial cortical anabolic adaptation compared with LC. In contrast, an attenuated cortical anabolic response presented at the proximal tibia in male ERβ-dOT mice at both ages. For the first time, our findings suggest that Ot-ERβ regulates bone (re)modeling and the response to mechanical signals through different mechanisms in males and females. © 2022 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).
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Affiliation(s)
- Xiaoyu Xu
- Weldon School of Biomedical EngineeringPurdue UniversityWest LafayetteINUSA
- Musculoskeletal Biology and Mechanics Lab, Department of Basic Medical SciencesPurdue UniversityWest LafayetteINUSA
| | - Haisheng Yang
- Department of Biomedical Engineering, Faculty of Environment and LifeBeijing University of TechnologyBeijingChina
| | | | - Maxim A. Gallant
- Musculoskeletal Biology and Mechanics Lab, Department of Basic Medical SciencesPurdue UniversityWest LafayetteINUSA
| | - Claes Ohlsson
- Sahlgrenska Osteoporosis Centre, Centre for Bone and Arthritis Research, Department of Internal Medicine and Clinical NutritionInstitute of Medicine, Sahlgrenska Academy, University of GothenburgGothenburgSweden
- Department of Drug TreatmentSahlgrenska University HospitalGothenburgSweden
| | - Teresita M. Bellido
- Department of Physiology and Cell BiologyUniversity of Arkansas for Medical SciencesLittle RockARUSA
| | - Russell P. Main
- Weldon School of Biomedical EngineeringPurdue UniversityWest LafayetteINUSA
- Musculoskeletal Biology and Mechanics Lab, Department of Basic Medical SciencesPurdue UniversityWest LafayetteINUSA
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8
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Vadivalagan C, Krishnan A, Chen SJ, Hseu YC, Muthu S, Dhar R, Aljabali AAA, Tambuwala MM. The Warburg effect in osteoporosis: Cellular signaling and epigenetic regulation of energy metabolic events to targeting the osteocalcin for phenotypic alteration. Cell Signal 2022; 100:110488. [PMID: 36208706 DOI: 10.1016/j.cellsig.2022.110488] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Revised: 09/30/2022] [Accepted: 10/01/2022] [Indexed: 02/08/2023]
Abstract
Osteoporosis is a silent disease of skeletal morphology that induces fragility and fracture risk in aged persons irrespective of gender. Juvenile secondary osteoporosis is rare and is influenced by familial genetic abnormalities. Despite the currently available therapeutic options, more-acute treatments are in need. Women suffer from osteoporosis after menopause, which is characterized by a decline in the secretion of sex hormones in the later phase of life. Several studies in the past two decades emphasized hormone-related pathways to combat osteoporosis. Some studies partially examined energy-related pathways, but achieving a more vivid picture of metabolism and bone remodeling in terms of the Warburg phenomenon is still warranted. Each cell requires sufficient energy for cellular propagation and growth; in particular, osteoporosis is an energy-dependent mechanism affected by a decreased cellular mass of the bone morphology. Energy utilization is the actual propagation of such diseases, and narrowing down these criteria will hopefully provide clues to formulate better therapeutic strategies. Oxidative glycolysis is a particular type of energy metabolic pathway in cancer cells that influences cellular proliferation. Therefore, the prospect of utilizing collective glucose metabolism by inducing the Warburg effect may improve cell propagation. The benefits of utilizing the energy from the Warburg effect may be a difficult task. However, it seems to improve their effectiveness in the osteoblast phenotype by connecting the selected pathways such as WNT, Notch, AKT, and Insulin signaling by targeting osteocalcin resulting in phenotypic alteration. Osteocalcin directs ATP utilization through the sclerostin SOST gene in the bone microenvironment. Thus, selective activation of ATP production involved in osteoblast maturation remains a prime strategy to fight osteoporosis.
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Affiliation(s)
- Chithravel Vadivalagan
- Department of Cosmeceutics, College of Biopharmaceutical and Food Sciences, China Medical University, Taichung 40402, Taiwan.
| | - Anand Krishnan
- Department of Chemical Pathology, School of Pathology, Faculty of Health Sciences, University of the Free State, Bloemfontein 9300, South Africa.
| | - Siang-Jyun Chen
- Institute of Nutrition, College of Health Care, China Medical University, Taichung, 406040, Taiwan
| | - You-Cheng Hseu
- Department of Cosmeceutics, College of Biopharmaceutical and Food Sciences, China Medical University, Taichung 40402, Taiwan; Department of Health and Nutrition Biotechnology, Asia University, 41354, Taiwan; Chinese Medicine Research Center, China Medical University, Taichung 40402, Taiwan; Research Center of Chinese Herbal Medicine, China Medical University, Taichung 40402, Taiwan.
| | - Sathish Muthu
- Department of Orthopaedics, Government Medical College and Hospital, Dindigul-624003, Tamil Nadu, India
| | - Rajib Dhar
- Department of Genetic Engineering, SRM Institute of Science and Technology, Kattankulathur, -603203, Tamilnadu, India
| | - Alaa A A Aljabali
- Department of Pharmaceutics and Pharmaceutical Technology, Yarmouk University, Irbid, 21163, Jordan
| | - Murtaza M Tambuwala
- Lincoln Medical School, University of Lincoln, Brayford Pool Campus, Lincoln LN6 7TS, UK.
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9
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Hayakawa A, Kurokawa T, Kanemoto Y, Sawada T, Mori J, Kato S. Skeletal and gene-regulatory functions of nuclear sex steroid hormone receptors. J Bone Miner Metab 2022; 40:361-374. [PMID: 35076781 DOI: 10.1007/s00774-021-01306-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Accepted: 12/16/2021] [Indexed: 10/19/2022]
Abstract
The wide variety of sex hormone actions underlie bone growth and health, and their actions mediate gene regulation by the cognate nuclear receptors. Nuclear androgen and estrogen receptors (AR, and ERα/ERβ) are hormone-dependent and DNA binding- transcription regulatory factors, and gene regulation by sex hormones often accompany with chromatin remodeling under aid of a number of co-regulators. As sex hormone biosynthesis is under highly regulated systemic and local regulations, the skeletal actions of sex hormones could be inferred from only the phenotypic abnormalities in skeleton in mouse genetic models deficient of nuclear receptors selectively in specific types of bone cells as well as at specific cell differentiation stages. Anabolic androgen actions and anti-bone resorptive estrogen actions are discussed here from the phenotypic abnormalities in such model mice. Though rapid gene regulation by sex hormones may not require chromatin reorganization, dynamic chromatin reconfiguration looks to facilitate profound and long-term hormonal actions. In this review, we focus the recent findings in gene regulation at a chromatin level, particularly of the function of enhancer RNAs transcribed from strong enhancers, and in the role of liquid-liquid phase separation state in transcription initiation through chromatin reconfiguration.
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Affiliation(s)
- Akira Hayakawa
- Graduate School of Life Science and Engineering, Iryo Sosei University, 5-5-1, Iino, Chuo-dai, Iwaki, Fukushima, 9708551, Japan
- Research Institute of Innovative Medicine, Tokiwa Foundation, Iwaki, Fukushima, Japan
| | - Tomohiro Kurokawa
- Graduate School of Life Science and Engineering, Iryo Sosei University, 5-5-1, Iino, Chuo-dai, Iwaki, Fukushima, 9708551, Japan
- Research Institute of Innovative Medicine, Tokiwa Foundation, Iwaki, Fukushima, Japan
- School of Medicine, Fukushima Medical University, Fukushima, Fukushima, 960-1295, Japan
| | - Yoshiaki Kanemoto
- Graduate School of Life Science and Engineering, Iryo Sosei University, 5-5-1, Iino, Chuo-dai, Iwaki, Fukushima, 9708551, Japan
- Research Institute of Innovative Medicine, Tokiwa Foundation, Iwaki, Fukushima, Japan
| | - Takahiro Sawada
- Graduate School of Life Science and Engineering, Iryo Sosei University, 5-5-1, Iino, Chuo-dai, Iwaki, Fukushima, 9708551, Japan
- Research Institute of Innovative Medicine, Tokiwa Foundation, Iwaki, Fukushima, Japan
| | - Jinichi Mori
- Graduate School of Life Science and Engineering, Iryo Sosei University, 5-5-1, Iino, Chuo-dai, Iwaki, Fukushima, 9708551, Japan
- Research Institute of Innovative Medicine, Tokiwa Foundation, Iwaki, Fukushima, Japan
- Department of Hematology, Jyoban Hospital, Tokiwa Foundation, Iwaki, Fukushima, Japan
- School of Medicine, Fukushima Medical University, Fukushima, Fukushima, 960-1295, Japan
| | - Shigeaki Kato
- Graduate School of Life Science and Engineering, Iryo Sosei University, 5-5-1, Iino, Chuo-dai, Iwaki, Fukushima, 9708551, Japan.
- Research Institute of Innovative Medicine, Tokiwa Foundation, Iwaki, Fukushima, Japan.
- School of Medicine, Fukushima Medical University, Fukushima, Fukushima, 960-1295, Japan.
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10
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Targeted activation of androgen receptor signaling in the periosteum improves bone fracture repair. Cell Death Dis 2022; 13:123. [PMID: 35136023 PMCID: PMC8826926 DOI: 10.1038/s41419-022-04595-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Revised: 12/30/2021] [Accepted: 01/27/2022] [Indexed: 12/03/2022]
Abstract
Low testosterone level is an independent predictor of osteoporotic fracture in elderly men as well as increased fracture risk in men undergoing androgen deprivation. Androgens and androgen receptor (AR) actions are essential for bone development and homeostasis but their linkage to fracture repair remains unclear. Here we found that AR is highly expressed in the periosteum cells and is co-localized with a mesenchymal progenitor cell marker, paired-related homeobox protein 1 (Prrx1), during bone fracture repair. Mice lacking the AR gene in the periosteum expressing Prrx1-cre (AR-/Y;Prrx1::Cre) but not in the chondrocytes (AR-/Y;Col-2::Cre) exhibits reduced callus size and new bone volume. Gene expression data analysis revealed that the expression of several collagens, integrins and cell adhesion molecules were downregulated in periosteum-derived progenitor cells (PDCs) from AR-/Y;Prrx1::Cre mice. Mechanistically, androgens-AR signaling activates the AR/ARA55/FAK complex and induces the collagen-integrin α2β1 gene expression that is required for promoting the AR-mediated PDCs migration. Using mouse cortical-defect and femoral graft transplantation models, we proved that elimination of AR in periosteum of host mice impairs fracture healing, regardless of AR existence of transplanted donor graft. While testosterone implanted scaffolds failed to complete callus bridging across the fracture gap in AR-/Y;Prrx1::Cre mice, cell-based transplantation using DPCs re-expressing AR could lead to rescue bone repair. In conclusion, targeting androgen/AR axis in the periosteum may provide a novel therapy approach to improve fracture healing.
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Artsi H, Cohen-Kfir E, Shahar R, Kalish-Achrai N, Lishinsky N, Dresner-Pollak R. SIRT1 haplo-insufficiency results in reduced cortical bone thickness, increased porosity and decreased estrogen receptor alpha in bone in adult 129/Sv female mice. Front Endocrinol (Lausanne) 2022; 13:1032262. [PMID: 36568088 PMCID: PMC9768543 DOI: 10.3389/fendo.2022.1032262] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Accepted: 11/15/2022] [Indexed: 12/12/2022] Open
Abstract
INTRODUCTION Sirtuin 1 (SIRT1) is a key player in aging and metabolism and regulates bone mass and architecture. Sexual dimorphism in skeletal effects of SIRT1 has been reported, with an unfavorable phenotype primarily in female mice. METHODS To investigate the mechanisms of gender differences in SIRT1 skeletal effect, we investigated femoral and vertebral cortical and cancellous bone in global Sirt1 haplo-insufficient 129/Sv mice aged 2,7,12 months lacking Sirt1 exons 5,6,7 (Sirt1+/Δ ) and their wild type (WT) counterparts. RESULTS In females, femoral bone mineral content, peak cortical thickness, and trabecular bone volume (BV/TV%), number and thickness were significantly lower in Sirt1+/Δ compared to WT mice. Increased femoral cortical porosity was observed in 7-month-old Sirt1+/Δ compared to WT female mice, accompanied by reduced biomechanical strength. No difference in vertebral indices was detected between Sirt1+/Δ and WT female mice. SIRT1 decreased with aging in WT female mice and was lower in vertebrae and femur in 18- and 30- versus 3-month-old 129/Sv and C57BL/6J female mice, respectively. Decreased bone estrogen receptor alpha (ERα) was observed in Sirt1+/Δ compared to WT female mice and was significantly higher in Sirt1 over-expressing C3HT101/2 murine mesenchymal stem cells. In males no difference in femoral indices was detected in Sirt1+/Δ versus WT mice, however vertebral BV/TV%, trabecular number and thickness were higher in Sirt1+/Δ vs. WT mice. No difference in androgen receptor (AR) was detected in bone in Sirt1+/Δ vs. WT male mice. Bone SIRT1 was significantly lower in male compared to female WT mice, suggesting that SIRT1 maybe more significant in female than male skeleton. DISCUSSION These findings demonstrate that 50% reduction in SIRT1 is sufficient to induce the hallmarks of skeletal aging namely, decreased cortical thickness and increased porosity in female mice, highlighting the role of SIRT1 as a regulator of cortical bone quantity and quality. The effects of SIRT1 in cortical bone are likely mediated in part by its regulation of ERα. The age-associated decline in bone SIRT1 positions SIRT1 as a potential therapeutic target to ameliorate age-related cortical bone deterioration in females. The crosstalk between ERα, AR and SIRT1 in the bone microenvironment remains to be further investigated.
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Affiliation(s)
- Hanna Artsi
- Department of Endocrinology and Metabolism, Division of Medicine, Hadassah Medical Organization, Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Einav Cohen-Kfir
- Department of Endocrinology and Metabolism, Division of Medicine, Hadassah Medical Organization, Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Ron Shahar
- Laboratory of Bone Biomechanics, Koret School of Veterinary Medicine, Faculty of Agriculture, Hebrew University of Jerusalem, Rehovot, Israel
| | - Noga Kalish-Achrai
- Laboratory of Bone Biomechanics, Koret School of Veterinary Medicine, Faculty of Agriculture, Hebrew University of Jerusalem, Rehovot, Israel
| | - Natan Lishinsky
- Department of Endocrinology and Metabolism, Division of Medicine, Hadassah Medical Organization, Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Rivka Dresner-Pollak
- Department of Endocrinology and Metabolism, Division of Medicine, Hadassah Medical Organization, Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem, Israel
- *Correspondence: Rivka Dresner-Pollak,
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12
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Huang J, Hagberg Thulin M, Damber JE, Welén K. The roles of RUNX2 and osteoclasts in regulating expression of steroidogenic enzymes in castration-resistant prostate cancer cells. Mol Cell Endocrinol 2021; 535:111380. [PMID: 34216642 DOI: 10.1016/j.mce.2021.111380] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/01/2021] [Revised: 06/08/2021] [Accepted: 06/29/2021] [Indexed: 12/25/2022]
Abstract
Intratumoral steroidogenesis is involved in development of castration-resistant prostate cancer (CRPC) as bone metastases. The osteoblast transcription factor RUNX2 influences steroidogenesis and is induced in CRPC cells by osteoblasts. This study investigates osteoclastic influence on RUNX2 in intratumoral steroidogenesis. Steroidogenic enzymes and steroid receptors were detected with immunohistochemistry in xenograft intratibial tumors from CRPC cells. In vitro, expression of RUNX2 was increased by osteoclasts in osteoblastic LNCaP-19 cells, but not in osteolytic PC-3. Silencing of RUNX2 downregulates expression of CYP11A1, CYP17A1 and HSD3B1 in LNCaP-19 cells co-cultured with osteoclasts, leading to inhibition of KLK3 expression. Osteoclasts promoted CYP11A1 and RUNX2 promoted AKR1C3, HSD17B3 and CYP19A1, but suppressed ESR2 in PC-3 cells. This study shows that osteoclasts promote RUNX2 regulated induction of key steroidogenic enzymes, influencing activation of androgen receptor in CRPC cells. The potential of RUNX2 as a target to inhibit progression of skeletal metastases of CRPC needs further investigation.
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Affiliation(s)
- Junchi Huang
- Department of Urology, Sahlgrenska Center for Cancer Research, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Sweden
| | - Malin Hagberg Thulin
- Department of Urology, Sahlgrenska Center for Cancer Research, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Sweden; Department of Internal Medicine and Clinical Nutrition, Centre for Bone and Arthritis Research, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Sweden
| | - Jan-Erik Damber
- Department of Urology, Sahlgrenska Center for Cancer Research, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Sweden; Region Västra Götaland, Sahlgrenska University Hospital, Department of Urology, Gothenburg, Sweden
| | - Karin Welén
- Department of Urology, Sahlgrenska Center for Cancer Research, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Sweden.
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13
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Moon HH, Clines KL, O'Day PJ, Al-Barghouthi BM, Farber EA, Farber CR, Auchus RJ, Clines GA. Osteoblasts Generate Testosterone From DHEA and Activate Androgen Signaling in Prostate Cancer Cells. J Bone Miner Res 2021; 36:1566-1579. [PMID: 33900658 PMCID: PMC8565089 DOI: 10.1002/jbmr.4313] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Revised: 04/13/2021] [Accepted: 04/17/2021] [Indexed: 01/25/2023]
Abstract
Bone metastasis is a complication of prostate cancer in up to 90% of men afflicted with advanced disease. Therapies that reduce androgen exposure remain at the forefront of treatment. However, most prostate cancers transition to a state whereby reducing testicular androgen action becomes ineffective. A common mechanism of this transition is intratumoral production of testosterone (T) using the adrenal androgen precursor dehydroepiandrosterone (DHEA) through enzymatic conversion by 3β- and 17β-hydroxysteroid dehydrogenases (3βHSD and 17βHSD). Given the ability of prostate cancer to form blastic metastases in bone, we hypothesized that osteoblasts might be a source of androgen synthesis. RNA expression analyses of murine osteoblasts and human bone confirmed that at least one 3βHSD and 17βHSD enzyme isoform was expressed, suggesting that osteoblasts are capable of generating androgens from adrenal DHEA. Murine osteoblasts were treated with 100 nM and 1 μM DHEA or vehicle control. Conditioned media from these osteoblasts were assayed for intermediate and active androgens by liquid chromatography-tandem mass spectrometry. As DHEA was consumed, the androgen intermediates androstenediol and androstenedione were generated and subsequently converted to T. Conditioned media of DHEA-treated osteoblasts increased androgen receptor (AR) signaling, prostate-specific antigen (PSA) production, and cell numbers of the androgen-sensitive prostate cancer cell lines C4-2B and LNCaP. DHEA did not induce AR signaling in osteoblasts despite AR expression in this cell type. We describe an unreported function of osteoblasts as a source of T that is especially relevant during androgen-responsive metastatic prostate cancer invasion into bone. © 2021 American Society for Bone and Mineral Research (ASBMR). This article has been contributed to by US Government employees and their work is in the public domain in the USA.
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Affiliation(s)
- Henry H Moon
- Department of Internal Medicine, Division of Metabolism, Endocrinology & Diabetes, University of Michigan, Ann Arbor, MI, USA
| | - Katrina L Clines
- Department of Internal Medicine, Division of Metabolism, Endocrinology & Diabetes, University of Michigan, Ann Arbor, MI, USA
| | - Patrick J O'Day
- Department of Internal Medicine, Division of Metabolism, Endocrinology & Diabetes, University of Michigan, Ann Arbor, MI, USA
| | | | - Emily A Farber
- Center for Public Health Genomics, University of Virginia, Charlottesville, VA, USA
| | - Charles R Farber
- Center for Public Health Genomics, University of Virginia, Charlottesville, VA, USA.,Departments of Public Health Sciences, and Biochemistry and Molecular Genetics, University of Virginia, Charlottesville, VA, USA
| | - Richard J Auchus
- Department of Internal Medicine, Division of Metabolism, Endocrinology & Diabetes, University of Michigan, Ann Arbor, MI, USA.,Endocrinology & Metabolism Section, Medicine Service, Veterans Affairs Medical Center, Ann Arbor, MI, USA
| | - Gregory A Clines
- Department of Internal Medicine, Division of Metabolism, Endocrinology & Diabetes, University of Michigan, Ann Arbor, MI, USA.,Endocrinology & Metabolism Section, Medicine Service, Veterans Affairs Medical Center, Ann Arbor, MI, USA
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14
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Zhao W, Peng Y, Hu Y, Guo XE, Li J, Cao J, Pan J, Feng JQ, Cardozo C, Jarvis J, Bauman WA, Qin W. Electrical stimulation of hindlimb skeletal muscle has beneficial effects on sublesional bone in a rat model of spinal cord injury. Bone 2021; 144:115825. [PMID: 33348128 PMCID: PMC7868091 DOI: 10.1016/j.bone.2020.115825] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Revised: 12/15/2020] [Accepted: 12/16/2020] [Indexed: 12/16/2022]
Abstract
Spinal cord injury (SCI) results in marked atrophy of sublesional skeletal muscle and substantial loss of bone. In this study, the effects of prolonged electrical stimulation (ES) and/or testosterone enanthate (TE) on muscle mass and bone formation in a rat model of SCI were tested. Compared to sham-transected animals, a significant reduction of the mass of soleus, plantaris and extensor digitorum longus (EDL) muscles was observed in animals 6 weeks post-SCI. Notably, ES or ES + TE resulted in the increased mass of the EDL muscles. ES or ES + TE significantly decreased mRNA levels of muscle atrophy markers (e.g., MAFbx and MurF1) in the EDL. Significant decreases in bone mineral density (BMD) (-27%) and trabecular bone volume (-49.3%) at the distal femur were observed in animals 6 weeks post injury. TE, ES and ES + TE treatment significantly increased BMD by +6.4%, +5.4%, +8.5% and bone volume by +22.2%, and +56.2% and+ 60.2%, respectively. Notably, ES alone or ES + TE resulted in almost complete restoration of cortical stiffness estimated by finite element analysis in SCI animals. Osteoblastogenesis was evaluated by colony-forming unit-fibroblastic (CFU-F) staining using bone marrow mesenchymal stem cells obtained from the femur. SCI decreased the CFU-F+ cells by -56.8% compared to sham animals. TE or ES + TE treatment after SCI increased osteoblastogenesis by +74.6% and +67.2%, respectively. An osteoclastogenesis assay revealed significantly increased TRAP+ multinucleated cells (+34.8%) in SCI animals compared to sham animals. TE, ES and TE + ES treatment following SCI markedly decreased TRAP+ cells by -51.3%, -40.3% and -46.9%, respectively. Each intervention greatly reduced the ratio of RANKL to OPG mRNA of sublesional long bone. Collectively, our findings demonstrate that after neurologically complete paralysis, dynamic muscle resistance exercise by ES reduced muscle atrophy, downregulated genes involved in muscle wasting, and restored mechanical loading to sublesional bone to a degree that allowed for the preservation of bone by inhibition of bone resorption and/or by facilitating bone formation.
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Affiliation(s)
- Wei Zhao
- National Center for the Medical Consequences of SCI, James J. Peters VA Medical Center, Bronx, NY, USA; Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Yuanzhen Peng
- National Center for the Medical Consequences of SCI, James J. Peters VA Medical Center, Bronx, NY, USA
| | - Yizhong Hu
- Department of Biomedical Engineering, Columbia University, New York, NY, USA
| | - X Edward Guo
- Department of Biomedical Engineering, Columbia University, New York, NY, USA
| | - Jiliang Li
- Indiana University Purdue University Indianapolis, Indianapolis, IN, USA
| | - Jay Cao
- United States Department of Agriculture Agricultural Research Service Human Nutrition Research Center, Grand Forks, ND, USA
| | - Jiangping Pan
- National Center for the Medical Consequences of SCI, James J. Peters VA Medical Center, Bronx, NY, USA
| | - Jian Q Feng
- Baylor College of Dentistry, TX A&M, Dallas, TX, USA
| | - Christopher Cardozo
- National Center for the Medical Consequences of SCI, James J. Peters VA Medical Center, Bronx, NY, USA; Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY, USA; Department of Rehabilitation Medicine, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Jonathan Jarvis
- School of Sport and Exercise Sciences, Liverpool John Moores University, Liverpool L3 3AF, United Kingdom
| | - William A Bauman
- National Center for the Medical Consequences of SCI, James J. Peters VA Medical Center, Bronx, NY, USA; Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY, USA; Department of Rehabilitation Medicine, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Weiping Qin
- National Center for the Medical Consequences of SCI, James J. Peters VA Medical Center, Bronx, NY, USA; Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
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15
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Chen JF, Lin PW, Tsai YR, Yang YC, Kang HY. Androgens and Androgen Receptor Actions on Bone Health and Disease: From Androgen Deficiency to Androgen Therapy. Cells 2019; 8:cells8111318. [PMID: 31731497 PMCID: PMC6912771 DOI: 10.3390/cells8111318] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2019] [Revised: 10/21/2019] [Accepted: 10/22/2019] [Indexed: 12/12/2022] Open
Abstract
Androgens are not only essential for bone development but for the maintenance of bone mass. Therefore, conditions with androgen deficiency, such as male hypogonadism, androgen-insensitive syndromes, and prostate cancer with androgen deprivation therapy are strongly associated with bone loss and increased fracture risk. Here we summarize the skeletal effects of androgens—androgen receptors (AR) actions based on in vitro and in vivo studies from animals and humans, and discuss bone loss due to androgens/AR deficiency to clarify the molecular basis for the anabolic action of androgens and AR in bone homeostasis and unravel the functions of androgen/AR signaling in healthy and disease states. Moreover, we provide evidence for the skeletal benefits of androgen therapy and elucidate why androgens are more beneficial than male sexual hormones, highlighting their therapeutic potential as osteoanabolic steroids in improving bone fracture repair. Finally, the application of selective androgen receptor modulators may provide new approaches for the treatment of osteoporosis and fractures as well as building stronger bones in diseases dependent on androgens/AR status.
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Affiliation(s)
- Jia-Feng Chen
- Division of Rheumatology, Allergy and Immunology, Department of Internal Medicine, Kaohsiung Chang-Gung Memorial Hospital and Chang Gung University, College of Medicine, Kaohsiung 833, Taiwan;
- Graduate Institute of Clinical Medical Sciences, College of Medicine, Chang Gung University, Kaohsiung 833, Taiwan; (P.-W.L.); (Y.-R.T.); (Y.-C.Y.)
| | - Pei-Wen Lin
- Graduate Institute of Clinical Medical Sciences, College of Medicine, Chang Gung University, Kaohsiung 833, Taiwan; (P.-W.L.); (Y.-R.T.); (Y.-C.Y.)
- Center for Menopause and Reproductive Medicine Research, Department of Obstetrics and Gynecology, Kaohsiung Chang-Gung Memorial Hospital and Chang Gung University, College of Medicine, Kaohsiung 833, Taiwan
| | - Yi-Ru Tsai
- Graduate Institute of Clinical Medical Sciences, College of Medicine, Chang Gung University, Kaohsiung 833, Taiwan; (P.-W.L.); (Y.-R.T.); (Y.-C.Y.)
- Center for Menopause and Reproductive Medicine Research, Department of Obstetrics and Gynecology, Kaohsiung Chang-Gung Memorial Hospital and Chang Gung University, College of Medicine, Kaohsiung 833, Taiwan
- An-Ten Obstetrics and Gynecology Clinic, Kaohsiung 802, Taiwan
| | - Yi-Chien Yang
- Graduate Institute of Clinical Medical Sciences, College of Medicine, Chang Gung University, Kaohsiung 833, Taiwan; (P.-W.L.); (Y.-R.T.); (Y.-C.Y.)
- Department of Dermatology, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung 833, Taiwan
| | - Hong-Yo Kang
- Graduate Institute of Clinical Medical Sciences, College of Medicine, Chang Gung University, Kaohsiung 833, Taiwan; (P.-W.L.); (Y.-R.T.); (Y.-C.Y.)
- Center for Menopause and Reproductive Medicine Research, Department of Obstetrics and Gynecology, Kaohsiung Chang-Gung Memorial Hospital and Chang Gung University, College of Medicine, Kaohsiung 833, Taiwan
- Correspondence: ; Tel.: +886-7-731-7123 (ext. 8898)
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16
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Ma W, Peltzer K, Qi L, Xu G, Liu Z, Wang J, Mao M, Chekhonin VP, Wang X, Zhang C. Female sex is associated with a lower risk of bone metastases and favourable prognosis in non-sex-specific cancers. BMC Cancer 2019; 19:1001. [PMID: 31653236 PMCID: PMC6815063 DOI: 10.1186/s12885-019-6168-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Accepted: 09/16/2019] [Indexed: 11/21/2022] Open
Abstract
Background The objectives were to investigate the disparity in the prevalence of bone metastases (BM) between the sexes and to assess the effect of female sex on the development and prognosis of BM. Methods Cases of invasive non-sex-specific cancers diagnosed between 2010 and 2015 in the Surveillance, Epidemiology, and End Results (SEER) program were used. The prevalence of BM was calculated by combining the prevalence of BM among different cancers. Multivariable logistic regression and proportion hazard regression were conducted to investigate the effect of female sex, and the results were pooled by meta-analysis. Results The pooled prevalence of BM among male and female patients was 2.3% (95% CI: 1.6–3.2%) and 1.8% (95% CI: 1.2–2.6%), respectively. The pooled prevalence of BM dramatically decreased for patients aged 11–40 years old, plateaued for patients aged 41–90 years old and increased for patients aged > 90 years old in both male and female patients. Meta-analysis suggested that female sex had a protective effect on the development of BM (pooled OR = 0.80; 95% CI: 0.75–0.84; p < .001) and a favourable prognosis for respiratory system cancers (pooled HR = 0.81; 95% CI: 0.71–0.92; p < .001). However, no significant associations existed for other cancers. Male non-sex-specific cancer patients and those with male-leaning genetic variations or hormonal status have a greater likelihood of developing BM than female patients. Conclusions Female sex was associated with fewer BM in various non-sex-specific cancers, and the effect was constant with changes in age. Female sex showed a protective effect exclusively on the prognosis of respiratory system cancers.
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Affiliation(s)
- Wenjuan Ma
- Department of Breast Imaging, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin's Clinical Research Center for Cancer, Tianjin, China
| | - Karl Peltzer
- Department of Research & Innovation, University of Limpopo, Turfloop, Mankweng, South Africa
| | - Lisha Qi
- Department of Pathology, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin's Clinical Research Center for Cancer, Tianjin, China
| | - Guijun Xu
- Department of Bone and Soft Tissue Tumors, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin's Clinical Research Center for Cancer, Huanhu Xi Road, Tianjin, 300060, China
| | - Zheng Liu
- Department of Bone and Soft Tissue Tumors, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin's Clinical Research Center for Cancer, Huanhu Xi Road, Tianjin, 300060, China
| | - Jingyi Wang
- Department of Pathology, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin's Clinical Research Center for Cancer, Tianjin, China
| | - Min Mao
- Department of Pathology and Southwest Cancer Center, First Affiliated Hospital, Army Medical University, Chongqing, 400038, China
| | - Vladimir P Chekhonin
- Department of Fundamental and Applied Neurobiology, V. P. Serbsky National Medical Research Center for Psychiatry and Narcology, the Ministry of Health of the Russian Federation, Moscow, Russia
| | - Xin Wang
- Department of Epidemiology and Biostatistics, First Affiliated Hospital, Army Medical University, 30 Gaotanyan Street, Shapingba District, 400038, China.
| | - Chao Zhang
- Department of Bone and Soft Tissue Tumors, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin's Clinical Research Center for Cancer, Huanhu Xi Road, Tianjin, 300060, China.
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Dimitri P. The Impact of Childhood Obesity on Skeletal Health and Development. J Obes Metab Syndr 2019; 28:4-17. [PMID: 31089575 PMCID: PMC6484936 DOI: 10.7570/jomes.2019.28.1.4] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Revised: 01/24/2019] [Accepted: 02/18/2019] [Indexed: 12/26/2022] Open
Abstract
Increased risk of fracture identified in obese children has led to a focus on the relationship between fat, bone, and the impact of obesity during skeletal development. Early studies have suggested that despite increased fracture risk, obese children have a higher bone mass. However, body size corrections applied to account for wide variations in size between children led to the finding that obese children have a lower total body and regional bone mass relative to their body size. Advances in skeletal imaging have shifted the focus from quantity of bone in obese children to evaluating the changes in bone microarchitecture that result in a change in bone quality and strength. The findings suggest that bone strength in the appendicular skeleton does not appropriately adapt to an increase in body size which results in a mismatch between bone strength and force from falls. Recent evidence points to differing influences of fat compartments on skeletal development-visceral fat may have a negative impact on bone which may be related to the associated adverse metabolic environment, while marrow adipose tissue may have an independent effect on trabecular bone development in obese children. The role of brown fat has received recent attention, demonstrating differences in the influence on bone mass between white and brown adipose tissues. Obesity results in a shift in growth and pubertal hormones as well as influences bone development through the altered release of adipokines. The change in the hormonal milieu provides an important insight into the skeletal changes observed in childhood obesity.
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Affiliation(s)
- Paul Dimitri
- Academic Unit of Child Health, The University of Sheffield, Sheffield, UK
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18
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Jardí F, Kim N, Laurent MR, Khalil R, Deboel L, Schollaert D, van Lenthe GH, Decallonne B, Carmeliet G, Claessens F, Vanderschueren D. Androgen Receptor in Neurons Slows Age-Related Cortical Thinning in Male Mice. J Bone Miner Res 2019; 34:508-519. [PMID: 30496619 DOI: 10.1002/jbmr.3625] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Revised: 10/30/2018] [Accepted: 11/05/2018] [Indexed: 12/26/2022]
Abstract
Androgens via the androgen receptor (AR) are required for optimal male bone health. The target cell(s) for the effects of androgens on cortical bone remain(s) incompletely understood. In females, estrogen receptor alpha in neurons is a negative regulator of cortical and trabecular bone. Whether neuronal AR regulates bone mass in males remains unexplored. Here, we inactivated AR in neurons using a tamoxifen-inducible CreERT2 under the control of the neuronal promoter Thy1. Tamoxifen induced a 70% to 80% reduction of AR mRNA levels in Thy1-CreERT2-positive brain regions cerebral cortex and brainstem as well as in the peripheral nervous tissue of male neuronal AR knockout (N-ARKO) mice. Hypothalamic AR mRNA levels were only marginally reduced and the hypothalamic-pituitary-gonadal axis remained unaffected, as determined by normal levels of serum testosterone, luteinizing hormone (LH), and follicle-stimulating hormone (FSH). In contrast to orchidectomy, deletion of neuronal AR did not alter body weight, body composition, hindlimb muscle mass, grip strength, or wheel running. MicroCT analysis of the femur revealed no changes in bone accrual during growth in N-ARKO mice. However, 36- and 46-week-old N-ARKO mice displayed an accelerated age-related cortical involution, namely a more pronounced loss of cortical thickness and strength, which occurred in the setting of androgen sufficiency. Neuronal AR inactivation decreased the cancellous bone volume fraction in L5 vertebra but not in the appendicular skeleton of aging mice. MicroCT findings were corroborated in the tibia and after normalization of hormonal levels. Serum markers of bone turnover and histomorphometry parameters were comparable between genotypes, except for a 30% increase in osteoclast surface in the trabecular compartment of 36-week-old N-ARKO mice. Cortical bone loss in N-ARKO mice was associated with an upregulation of Ucp1 expression in brown adipose tissue, a widely used readout for sympathetic tone. We conclude that androgens preserve cortical integrity in aging male mice via AR in neurons. © 2018 American Society for Bone and Mineral Research.
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Affiliation(s)
- Ferran Jardí
- Clinical and Experimental Endocrinology, Department of Chronic Diseases, Metabolism and Aging (CHROMETA), KU Leuven, Leuven, Belgium
| | - Nari Kim
- Clinical and Experimental Endocrinology, Department of Chronic Diseases, Metabolism and Aging (CHROMETA), KU Leuven, Leuven, Belgium
| | - Michaël R Laurent
- Molecular Endocrinology Laboratory, Department of Cellular and Molecular Medicine, KU Leuven, Leuven, Belgium.,Gerontology and Geriatrics, Department of Chronic Diseases, Metabolism and Aging (CHROMETA), KU Leuven, Leuven, Belgium
| | - Rougin Khalil
- Clinical and Experimental Endocrinology, Department of Chronic Diseases, Metabolism and Aging (CHROMETA), KU Leuven, Leuven, Belgium
| | - Ludo Deboel
- Clinical and Experimental Endocrinology, Department of Chronic Diseases, Metabolism and Aging (CHROMETA), KU Leuven, Leuven, Belgium
| | - Dieter Schollaert
- Clinical and Experimental Endocrinology, Department of Chronic Diseases, Metabolism and Aging (CHROMETA), KU Leuven, Leuven, Belgium
| | - G H van Lenthe
- Biomechanics Section, Department of Mechanical Engineering, KU Leuven, Leuven, Belgium
| | - Brigitte Decallonne
- Clinical and Experimental Endocrinology, Department of Chronic Diseases, Metabolism and Aging (CHROMETA), KU Leuven, Leuven, Belgium
| | - Geert Carmeliet
- Clinical and Experimental Endocrinology, Department of Chronic Diseases, Metabolism and Aging (CHROMETA), KU Leuven, Leuven, Belgium
| | - Frank Claessens
- Molecular Endocrinology Laboratory, Department of Cellular and Molecular Medicine, KU Leuven, Leuven, Belgium
| | - Dirk Vanderschueren
- Clinical and Experimental Endocrinology, Department of Chronic Diseases, Metabolism and Aging (CHROMETA), KU Leuven, Leuven, Belgium
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19
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Wu J, Henning P, Sjögren K, Koskela A, Tuukkanen J, Movérare-Skrtic S, Ohlsson C. The androgen receptor is required for maintenance of bone mass in adult male mice. Mol Cell Endocrinol 2019; 479:159-169. [PMID: 30308267 DOI: 10.1016/j.mce.2018.10.008] [Citation(s) in RCA: 17] [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: 05/14/2018] [Revised: 08/10/2018] [Accepted: 10/07/2018] [Indexed: 12/12/2022]
Abstract
Previous studies evaluating the role of the androgen receptor (AR) for bone mass have used mouse models with global or tissue-specific lifelong inactivation of the AR. However, these mouse models have the AR inactivated already early in life and the relative roles of the AR during development, sexual maturation and in adult mice cannot be evaluated separately. The aim of the present study was to determine the specific roles of the AR in bone during sexual maturation and in adult mice. The AR was conditionally ablated at four (pre-pubertal) or ten (post-pubertal) weeks of age in male mice using tamoxifen-inducible Cre-mediated recombination. Both the pre-pubertal and the post-pubertal AR inactivation were efficient demonstrated by substantially lower AR mRNA levels in seminal vesicle, bone and white adipose tissue as well as markedly reduced weights of reproductive tissues when comparing inducible ARKO mice and control mice at 14 weeks of age. Total body BMD, as analyzed by DXA, as well as tibia diaphyseal cortical bone thickness and proximal metaphyseal trabecular bone volume fraction, as analyzed by μCT, were significantly reduced by both pre-pubertal and post-pubertal AR inactivation. These bone effects were associated with an increased bone turnover, indicating a high bone turnover osteoporosis. Pre-pubertal but not post-pubertal AR inactivation resulted in substantially increased fat mass. In conclusion, the AR is required for maintenance of both trabecular and cortical bone in adult male mice while AR expression during puberty is crucial for normal fat mass homeostasis in adult male mice.
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Affiliation(s)
- Jianyao Wu
- Centre for Bone and Arthritis Research, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Petra Henning
- Centre for Bone and Arthritis Research, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Klara Sjögren
- Centre for Bone and Arthritis Research, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Antti Koskela
- Department of Anatomy and Cell Biology, Medical Research Center, University of Oulu, Oulu, Finland
| | - Juha Tuukkanen
- Department of Anatomy and Cell Biology, Medical Research Center, University of Oulu, Oulu, Finland
| | - Sofia Movérare-Skrtic
- Centre for Bone and Arthritis Research, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Claes Ohlsson
- Centre for Bone and Arthritis Research, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
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20
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Abstract
In both sexes, estrogen is one of the most essential hormones for maintaining bone integrity. Also, especially in men, androgen has beneficial effects on bone independent of estrogen. However, estrogen replacement therapy for postmenopausal women increases the risk of developing breast cancer and endometrial cancer, and androgen replacement therapy for partial androgen deficiency of the aging male increases the risk of developing prostate cancer. Various mechanisms have been proposed on the effects of gonadal hormones on bone, such as effects through cytokines including IL-6 and effects on the OPG/RANKL ratio. In addition, large amounts of new information deriving from high-throughput gene expression analysis raise the possibility of multiple other effects on bone cells. Both estrogen and androgen exert their effects via the estrogen receptor (ER) or the androgen receptor (AR), which belongs to the nuclear receptor superfamily. Compounds such as selective estrogen receptor modulators (SERMs) and selective androgen receptor modulators (SARMs) also bind ER and AR, respectively. However, SERMs and SARMs alter the ER or AR structure differently from estrogen or androgen, resulting in other downstream gene responses. As a result they can exert favorable effects on bone while suppressing the undesirable actions of estrogen and androgen. Elucidation of ER and AR ligand-specific and tissue-specific gene regulation mechanisms will also provide information on the signal transduction mechanisms of other nuclear receptors and will be valuable for the development of new therapeutic agents.
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21
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Manolagas SC. The Quest for Osteoporosis Mechanisms and Rational Therapies: How Far We've Come, How Much Further We Need to Go. J Bone Miner Res 2018; 33:371-385. [PMID: 29405383 PMCID: PMC6816306 DOI: 10.1002/jbmr.3400] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Revised: 01/25/2018] [Accepted: 01/27/2018] [Indexed: 12/30/2022]
Abstract
During the last 40 years, understanding of bone biology and the pathogenesis of osteoporosis, the most common and impactful bone disease of old age, has improved dramatically thanks to basic and clinical research advances, genetic insights from humans and rodents, and newer imaging technologies. Culprits of osteoporosis are no longer a matter of speculation based on in vitro observations. Instead, they can be identified and dissected at the cellular and molecular level using genetic approaches; and their effect on distinct bone envelopes and anatomic regions can be functionally assessed in vivo. The landscape of pharmacotherapies for osteoporosis has also changed profoundly with the emergence of several potent antiresorptive drugs as well as anabolic agents, displacing estrogen replacement as the treatment of choice. In spite of these major positive developments, the optimal duration of the available therapies and their long-term safety remain matters of conjecture and some concern. Moreover, antiresorptive therapies are used indiscriminately for patients of all ages on the assumption that suppressing remodeling is always beneficial for bone, but rebound remodeling upon their discontinuation suggests otherwise. In this invited perspective, I highlight the latest state of knowledge of bone-intrinsic and extrinsic mechanisms responsible for the development of osteoporosis in both sexes; differences between the mechanisms responsible for the effects of aging and estrogen deficiency; and the role of old osteocytes in the development of cortical porosity. In addition, I highlight advances toward the goal of developing drugs for several degenerative diseases of old age at once, including osteoporosis, by targeting shared mechanisms of aging. © 2018 American Society for Bone and Mineral Research.
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Affiliation(s)
- 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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22
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Khosla S, Monroe DG. Regulation of Bone Metabolism by Sex Steroids. Cold Spring Harb Perspect Med 2018; 8:cshperspect.a031211. [PMID: 28710257 DOI: 10.1101/cshperspect.a031211] [Citation(s) in RCA: 144] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Osteoporosis is a significant public health problem, and a major cause of the disease is estrogen deficiency following menopause in women. In addition, considerable evidence now shows that estrogen is also a major regulator of bone metabolism in men. Since the original description of the effects of estrogen deficiency on bone by Fuller Albright more than 70 years ago, there has been enormous progress in understanding the mechanisms of estrogen and testosterone action on bone using human and mouse models. Although we understand more about the effects of estrogen on bone as compared with testosterone, both sex steroids do play important roles, perhaps in a somewhat compartment-specific (i.e., cancellous vs. cortical bone) manner. This review summarizes our current knowledge of sex steroid action on bone based on human and mouse studies, identifies both agreements and potential discrepancies between these studies, and suggests directions for future research in this important area.
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Affiliation(s)
- Sundeep Khosla
- Robert and Arlene Kogod Center on Aging and Endocrine Research Unit, Mayo Clinic College of Medicine, Rochester, Minnesota 55905
| | - David G Monroe
- Robert and Arlene Kogod Center on Aging and Endocrine Research Unit, Mayo Clinic College of Medicine, Rochester, Minnesota 55905
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23
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Takayama KI. The biological and clinical advances of androgen receptor function in age-related diseases and cancer [Review]. Endocr J 2017; 64:933-946. [PMID: 28824023 DOI: 10.1507/endocrj.ej17-0328] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Hormonal alterations with aging contribute to the pathogenesis of several diseases. Androgens mediate their effects predominantly through binding to the androgen receptor (AR), a member of the ligand-dependent nuclear receptor superfamily. By androgen treatment, AR is recruited to specific genomic loci dependent on tissue specific pioneer factors to regulate target gene expression. Recent studies have revealed the epigenetic modulation by AR-associated histone modifiers and the roles of non-coding RNAs in AR signaling. Androgens are male sex hormone to induce differentiation of the male reproductive system required for the establishment of adult sexual function. As shown by several reports using AR knockout mouse models, androgens also have anabolic functions in several tissues such as bone, muscle and central nervous systems. Notably, AR has a central role in prostate cancer progression. Prostate cancer is the most frequently diagnosed cancer in men. Androgen-deprivation therapy for cancer patients and decline of serum androgen with aging promote several diseases associated with aging and quality of life of older men such as osteoporosis, sarcopenia and dementia. Thus, androgen replacement therapy for treating late onset hypogonadism (LOH) or new epigenetic regulators have the potential to overcome the symptoms caused by the low androgen, although adverse effects for cardiovascular diseases have been reported. Given the increasing longevity and consequent rise of age-related diseases and prostate cancer patients, a more understanding of the AR actions in male health remains a high research priority.
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Affiliation(s)
- Ken-Ichi Takayama
- Department of Functional Biogerontology, Tokyo Metropolitan Institute of Gerontology, Itabashi-ku, Tokyo 173-0015, Japan
- Department of Geriatric Medicine, Graduate School of Medicine, the University of Tokyo, Japan
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24
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Zhong ZA, Kot A, Lay YAE, Zhang H, Jia J, Lane NE, Yao W. Sex-Dependent, Osteoblast Stage-Specific Effects of Progesterone Receptor on Bone Acquisition. J Bone Miner Res 2017; 32:1841-1852. [PMID: 28569405 PMCID: PMC5611815 DOI: 10.1002/jbmr.3186] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Revised: 05/22/2017] [Accepted: 05/27/2017] [Indexed: 12/12/2022]
Abstract
The role of the progesterone receptor (PR) in the regulation of sexual dimorphism in bone has yet to be determined. Here we utilized genetic fate mapping and Western blotting to demonstrate age-dependent PR expression in the mouse femoral metaphysis and diaphysis. To define sex-dependent and osteoblast stage-specific effects of PR on bone acquisition, we selectively deleted PR at different stages of osteoblast differentiation. We found that when Prx1-Cre mice were crossed with PR floxed mice to generate a mesenchymal stem cell (MSC) conditional KO model (Prx1; PRcKO), the mutant mice developed greater trabecular bone volume with higher mineral apposition rate and bone formation. This may be explained by increased number of MSCs and greater osteogenic potential, particularly in males. Age-related trabecular bone loss was similar between the Prx1; PRcKO mice and their WT littermates in both sexes. Hormone deficiency during the period of rapid bone growth induced rapid trabecular bone loss in both the WT and the Prx1; PRcKO mice in both sexes. No differences in trabecular bone mass was observed when PR was deleted in mature osteoblasts using osteocalcin-Cre (Bglap-Cre). Also, there were no differences in cortical bone mass in all three PRcKO mice. In conclusion, PR inactivation in early osteoprogenitor cells but not in mature osteoblasts influenced trabecular bone accrual in a sex-dependent manner. PR deletion in osteoblast lineage cells did not affect cortical bone mass. © 2017 American Society for Bone and Mineral Research.
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Affiliation(s)
- Zhendong A. Zhong
- Center for Musculoskeletal Health, Department of Internal Medicine, University of California Davis Medical Center, Sacramento, CA 95817, USA
- Center for Cancer and Cell Biology, Program in Skeletal Disease and Tumor Microenvironment, Van Andel Research Institute, Grand Rapids MI 49503, USA
| | - Alexander Kot
- Center for Musculoskeletal Health, Department of Internal Medicine, University of California Davis Medical Center, Sacramento, CA 95817, USA
| | - Yu-An E. Lay
- Center for Musculoskeletal Health, Department of Internal Medicine, University of California Davis Medical Center, Sacramento, CA 95817, USA
| | - Hongliang Zhang
- Center for Musculoskeletal Health, Department of Internal Medicine, University of California Davis Medical Center, Sacramento, CA 95817, USA
- Department of Emergency Medicine, Center for Rare Diseases, Second Xiangya Hospital of the Central-South University, Hunan, Changsha, China
| | - Junjing Jia
- Center for Musculoskeletal Health, Department of Internal Medicine, University of California Davis Medical Center, Sacramento, CA 95817, USA
| | - Nancy E. Lane
- Center for Musculoskeletal Health, Department of Internal Medicine, University of California Davis Medical Center, Sacramento, CA 95817, USA
| | - Wei Yao
- Center for Musculoskeletal Health, Department of Internal Medicine, University of California Davis Medical Center, Sacramento, CA 95817, USA
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25
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A Case of Male Osteoporosis: A 37-Year-Old Man with Multiple Vertebral Compression Fractures. Case Rep Endocrinol 2017; 2017:6328524. [PMID: 28791186 PMCID: PMC5534275 DOI: 10.1155/2017/6328524] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2017] [Accepted: 06/14/2017] [Indexed: 11/30/2022] Open
Abstract
While the contributing role of testosterone to bone health is rather modest compared to other factors such as estradiol levels, male hypogonadism is associated with low bone mass and fragility fractures. Along with stimulating physical puberty by achieving virilization and a normal muscle mass and improving psychosocial wellbeing, the goals of testosterone replacement therapy in male hypogonadism also include attainment of age-specific bone mineral density. We report on a 37-year-old man who presented with multiple vertebral compression fractures several years following termination of testosterone replacement therapy for presumed constitutional delay in growth and puberty. Here, we discuss the management of congenital hypogonadotropic hypogonadism with hyposmia (Kallmann syndrome), with which the patient was ultimately diagnosed, the role of androgens in the acquisition of bone mass during puberty and its maintenance thereafter, and outline specific management strategies for patients with hypogonadism and high risk for fragility fractures.
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26
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Farach-Carson MC, Lin SH, Nalty T, Satcher RL. Sex Differences and Bone Metastases of Breast, Lung, and Prostate Cancers: Do Bone Homing Cancers Favor Feminized Bone Marrow? Front Oncol 2017; 7:163. [PMID: 28824875 PMCID: PMC5545941 DOI: 10.3389/fonc.2017.00163] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2017] [Accepted: 07/19/2017] [Indexed: 12/18/2022] Open
Abstract
Sex-associated differences in bone metastasis formation from breast, lung, and prostate cancer exist in clinical studies, but have not been systematically reviewed. Differences in the bone marrow niche can be attributed to sexual dimorphism, to genetic variations that affect sex hormone levels, or to the direct effects of sex hormones, natural or exogenously delivered. This review describes the present understanding of sex-associated and sex hormone level differences in the marrow niche and in formation of bone metastasis during the transition of these three cancers from treatable disease to an often untreatable, lethal metastatic one. Our purpose is to provide insight into some underlying molecular mechanisms for hormonal influence in bone metastasis formation, and to the potential influence of sexual dimorphism, genetic differences affecting sex assignment, and sex hormone level differences on the bone niche and its favorability for metastasis formation. We reviewed publications in PubMed and EMBASE, including full length manuscripts, case reports, and clinical studies of relevance to our topic. We focused on bone metastasis formation in breast, lung, and prostate cancer because all three commonly present with bone metastases. Several clear observations emerged. For breast cancer bone metastasis formation, estrogen receptor (ER) signaling pathways indicate a role for ER beta (ERβ). Estrogen influences the bone microenvironment, creating and conditioning a favorable niche for colonization and breast cancer progression. For lung cancer, studies support the hypothesis that females have a more favorable bone microenvironment for metastasis formation. For prostate cancer, a decrease in the relative androgen to estrogen balance or a “feminization” of bone marrow favors bone metastasis formation, with a potentially important role for ERβ that may be similar to that in breast cancer. Long-term estrogen administration or androgen blockade in males may feminize the bone marrow niche to one more favorable for bone metastases in prostate cancer. Administration of androgens in females, especially combined with mastectomy, may reduce risk of developing bone metastatic breast cancer. We conclude that it should be considered that females, those with female-leaning genetic variations, or hormonal states that feminize the bone marrow, may offer favorable sites for bone metastases.
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Affiliation(s)
- Mary C Farach-Carson
- Department of Diagnostic and Biomedical Sciences, School of Dentistry, The University of Texas Health Science Center at Houston, Houston, TX, United States
| | - Sue-Hwa Lin
- Department of Translational Molecular Pathology, The University of Texas MD Anderson Cancer Center, Houston, TX, United States
| | - Theresa Nalty
- Department of Orthopaedic Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, United States
| | - Robert L Satcher
- Department of Orthopaedic Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, United States
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27
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Golds G, Houdek D, Arnason T. Male Hypogonadism and Osteoporosis: The Effects, Clinical Consequences, and Treatment of Testosterone Deficiency in Bone Health. Int J Endocrinol 2017; 2017:4602129. [PMID: 28408926 PMCID: PMC5376477 DOI: 10.1155/2017/4602129] [Citation(s) in RCA: 67] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/29/2016] [Accepted: 02/07/2017] [Indexed: 01/22/2023] Open
Abstract
It is well recognized that bone loss accelerates in hypogonadal states, with female menopause being the classic example of sex hormones affecting the regulation of bone metabolism. Underrepresented is our knowledge of the clinical and metabolic consequences of overt male hypogonadism, as well as the more subtle age-related decline in testosterone on bone quality. While menopause and estrogen deficiency are well-known risk factors for osteoporosis in women, the effects of age-related testosterone decline in men on bone health are less well known. Much of our knowledge comes from observational studies and retrospective analysis on small groups of men with variable causes of primary or secondary hypogonadism and mild to overt testosterone deficiencies. This review aims to present the current knowledge of the consequences of adult male hypogonadism on bone metabolism. The direct and indirect effects of testosterone on bone cells will be explored as well as the important differences in male osteoporosis and assessment as compared to that in females. The clinical consequence of both primary and secondary hypogonadism, as well as testosterone decline in older males, on bone density and fracture risk in men will be summarized. Finally, the therapeutic options and their efficacy in male osteoporosis and hypogonadism will be discussed.
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Affiliation(s)
- Gary Golds
- Department of Medicine, University of Saskatchewan, Saskatoon, SK, Canada S7N 0W8
| | - Devon Houdek
- Department of Medicine, University of Saskatchewan, Saskatoon, SK, Canada S7N 0W8
| | - Terra Arnason
- Division of Endocrinology and Metabolism, Department of Medicine, University of Saskatchewan, Saskatoon, SK, Canada S7N 0W8
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28
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Siddiqui JA, Partridge NC. Physiological Bone Remodeling: Systemic Regulation and Growth Factor Involvement. Physiology (Bethesda) 2017; 31:233-45. [PMID: 27053737 DOI: 10.1152/physiol.00061.2014] [Citation(s) in RCA: 246] [Impact Index Per Article: 35.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Bone remodeling is essential for adult bone homeostasis. It comprises two phases: bone formation and resorption. The balance between the two phases is crucial for sustaining bone mass and systemic mineral homeostasis. This review highlights recent work on physiological bone remodeling and discusses our knowledge of how systemic and growth factors regulate this process.
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Affiliation(s)
- Jawed A Siddiqui
- Department of Basic Science and Craniofacial Biology, New York University College of Dentistry, New York, New York
| | - Nicola C Partridge
- Department of Basic Science and Craniofacial Biology, New York University College of Dentistry, New York, New York
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29
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Ucer S, Iyer S, Kim HN, Han L, Rutlen C, Allison K, Thostenson JD, de Cabo R, Jilka RL, O’Brien C, Almeida M, Manolagas SC. The Effects of Aging and Sex Steroid Deficiency on the Murine Skeleton Are Independent and Mechanistically Distinct. J Bone Miner Res 2017; 32:560-574. [PMID: 27714847 PMCID: PMC5340621 DOI: 10.1002/jbmr.3014] [Citation(s) in RCA: 79] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Revised: 09/22/2016] [Accepted: 09/30/2016] [Indexed: 12/17/2022]
Abstract
Old age and sex steroid deficiency are the two most critical factors for the development of osteoporosis. It remains unknown, however, whether the molecular culprits of the two conditions are similar or distinct. We show herein that at 19.5 months of age-a time by which the age-dependent decline of cortical and cancellous bone mass and cortical porosity were fully manifested in C57BL/6J mice-these animals remained functionally estrogen sufficient. Transgenic mice with conditional expression of mitochondria-targeted catalase-a potent H2 O2 inactivating enzyme-in cells of the myeloid lineage (mitoCAT;LysM-Cre mice) were protected from the loss of cortical, but not cancellous, bone caused by gonadectomy in either sex. Consistent with these findings, in vitro studies with ERα-deficient Prx1+ cells and gonadectomized young adult mice showed that in both sexes decreased ERα signaling in Prx1+ cells leads to an increase in SDF1, a.k.a. CXCL12, an osteoclastogenic cytokine whose effects were abrogated in macrophages from mitoCAT;LysM-Cre mice. In contrast to sex steroid deficiency, the adverse effects of aging on either cortical or cancellous bone were unaffected in mitoCAT;LysM-Cre mice. On the other hand, attenuation of H2 O2 generation in cells of the mesenchymal lineage targeted by Prx1-Cre partially prevented the loss of cortical bone caused by old age. Our results suggest the effects of sex steroid deficiency and aging on the murine skeleton are independent and result from distinct mechanisms. In the former, the prevailing mechanism of the cortical bone loss in both sexes is increased osteoclastogenesis caused by estrogen deficiency; this is likely driven, at least in part, by mesenchymal/stromal cell-derived SDF1. Decreased osteoblastogenesis, owing in part to increased H2 O2, combined with increased osteoclastogenesis caused by aging mechanisms independent of estrogen deficiency, are the prevailing mechanisms of the loss of cortical bone with old age. © 2016 American Society for Bone and Mineral Research.
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Affiliation(s)
- Serra Ucer
- 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
| | - Srividhya Iyer
- 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
| | - Ha-Neui Kim
- 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
| | - Li Han
- 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
| | - Christine Rutlen
- 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
| | - Kelly Allison
- 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
| | - Jeff D Thostenson
- Department of Biostatistics, University of Arkansas for Medical Sciences, Little Rock, AR, USA
| | - Rafael de Cabo
- Translational Gerontology Branch, National Institute on Aging, Baltimore, MD, USA
| | - Robert L Jilka
- 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
| | - Charles 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, AR, USA
| | - 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, AR, 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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Abstract
Nuclear receptors are a family of transcription factors that can be activated by lipophilic ligands. They are fundamental regulators of development, reproduction, and energy metabolism. In bone, nuclear receptors enable bone cells, including osteoblasts, osteoclasts, and osteocytes, to sense their dynamic microenvironment and maintain normal bone development and remodeling. Our views of the molecular mechanisms in this process have advanced greatly in the past decade. Drugs targeting nuclear receptors are widely used in the clinic for treating patients with bone disorders such as osteoporosis by modulating bone formation and resorption rates. Deficiency in the natural ligands of certain nuclear receptors can cause bone loss; for example, estrogen loss in postmenopausal women leads to osteoporosis and increases bone fracture risk. In contrast, excessive ligands of other nuclear receptors, such as glucocorticoids, can also be detrimental to bone health. Nonetheless, the ligand-induced osteoprotective effects of many other nuclear receptors, e.g., vitamin D receptor, are still in debate and require further characterizations. This review summarizes previous studies on the roles of nuclear receptors in bone homeostasis and incorporates the most recent findings. The advancement of our understanding in this field will help researchers improve the applications of agonists, antagonists, and selective modulators of nuclear receptors for therapeutic purposes; in particular, determining optimal pharmacological drug doses, preventing side effects, and designing new drugs that are more potent and specific.
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31
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Ajdžanović VZ, Filipović BR, Šošić Jurjević BT, Milošević VL. Testosterone supplementation, glucocorticoid milieu and bone homeostasis in the ageing male. Fundam Clin Pharmacol 2017; 31:372-382. [PMID: 28186359 DOI: 10.1111/fcp.12277] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2016] [Revised: 01/04/2017] [Accepted: 02/07/2017] [Indexed: 12/27/2022]
Abstract
Male ageing is entwined with a continuous fall in free testosterone levels, which contributes to the pathogenesis of bone loss. Glucocorticoid excess, either dependent on the ageing process or iatrogenically induced, was found to additionally impair the bone structure and metabolism. Cautious testosterone supplementation in this respect may positively affect the glucocorticoid milieu and bone homeostasis, while testosterone-induced changes in the glucocorticoid output could serve as a determinant of bone-related therapeutic outcome. Namely, bone mineral content/density, the parameters of trabecular bone structure as well as bone strength are enhanced, serum calcitonin levels tend to increase, while serum osteocalcin, serum parathyroid hormone and urinary calcium decrease, all upon testosterone administration to the ageing male. In parallel, testosterone application decreases glucocorticoid secretion in the animal models of male ageing, while clinical data in this field are still inconsistent. Importantly, a physiological link exists between testosterone-induced changes in glucocorticoid levels and the tendency of bone status improvement in the ageing male. We believe that the assessment of circulating adrenocorticotropic hormone concentrations together with glucocorticoid levels, reflecting the hypothalamic-pituitary-adrenal axis feedback loop operativeness during testosterone supplementation, represents a well-balanced bone-related therapeutic update.
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Affiliation(s)
- Vladimir Z Ajdžanović
- Department of Cytology, Institute for Biological Research 'Siniša Stanković', University of Belgrade, Despot Stefan Blvd. 142, 11060, Belgrade, Serbia
| | - Branko R Filipović
- Department of Cytology, Institute for Biological Research 'Siniša Stanković', University of Belgrade, Despot Stefan Blvd. 142, 11060, Belgrade, Serbia
| | - Branka T Šošić Jurjević
- Department of Cytology, Institute for Biological Research 'Siniša Stanković', University of Belgrade, Despot Stefan Blvd. 142, 11060, Belgrade, Serbia
| | - Verica Lj Milošević
- Department of Cytology, Institute for Biological Research 'Siniša Stanković', University of Belgrade, Despot Stefan Blvd. 142, 11060, Belgrade, Serbia
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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: 462] [Impact Index Per Article: 66.0] [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: 24] [Impact Index Per Article: 3.0] [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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Śliwiński L, Cegieła U, Pytlik M, Folwarczna J, Janas A, Zbrojkiewicz M. Effects of fenoterol on the skeletal system depend on the androgen level. Pharmacol Rep 2016; 69:260-267. [PMID: 28126642 DOI: 10.1016/j.pharep.2016.09.023] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2016] [Revised: 09/22/2016] [Accepted: 09/28/2016] [Indexed: 11/30/2022]
Abstract
BACKGROUND The role of sympathetic nervous system in the osseous tissue remodeling is not clear enough. METHODS The effects of fenoterol, a selective β2-adrenomimetic drug, on the skeletal system of normal and androgen deficient (orchidectomized) rats were studied in vivo. Osteoclastogenesis and mRNA expression in osteoblasts were investigated in vitro in mouse cell cultures. RESULTS Fenoterol administered to animals with physiological androgen level unfavorably affected the skeletal system, damaging the bone microarchitecture. Androgen deficiency induced osteoporotic changes, and fenoterol protected the osseous tissue from consequences of androgen deficiency. The results of in vitro studies correlated with the in vivo observations. A significantly increased number of osteoclasts in bone marrow cell cultures to which testosterone and fenoterol were added simultaneously was demonstrated. In cultures without the addition of testosterone, fenoterol significantly inhibited osteoclastogenesis in comparison with control cultures. CONCLUSIONS The results indicate the favorable action of fenoterol in conditions of testosterone deficiency, and its destructive influence upon the skeleton in the presence of androgens. The results confirm the key role of sympathetic nervous system in the regulation of bone remodeling.
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Affiliation(s)
- Leszek Śliwiński
- Department of Pharmacology, School of Pharmacy with the Division of Laboratory Medicine in Sosnowiec, Medical University of Silesia, Katowice, Poland.
| | - Urszula Cegieła
- Department of Pharmacology, School of Pharmacy with the Division of Laboratory Medicine in Sosnowiec, Medical University of Silesia, Katowice, Poland
| | - Maria Pytlik
- Department of Pharmacology, School of Pharmacy with the Division of Laboratory Medicine in Sosnowiec, Medical University of Silesia, Katowice, Poland
| | - Joanna Folwarczna
- Department of Pharmacology, School of Pharmacy with the Division of Laboratory Medicine in Sosnowiec, Medical University of Silesia, Katowice, Poland
| | - Aleksandra Janas
- Department of Pharmacology, School of Pharmacy with the Division of Laboratory Medicine in Sosnowiec, Medical University of Silesia, Katowice, Poland
| | - Małgorzata Zbrojkiewicz
- Department of Pharmacology, School of Pharmacy with the Division of Laboratory Medicine in Sosnowiec, Medical University of Silesia, Katowice, Poland
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Wang YG, Han XG, Yang Y, Qiao H, Dai KR, Fan QM, Tang TT. Functional differences between AMPK α1 and α2 subunits in osteogenesis, osteoblast-associated induction of osteoclastogenesis, and adipogenesis. Sci Rep 2016; 6:32771. [PMID: 27600021 PMCID: PMC5013406 DOI: 10.1038/srep32771] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2016] [Accepted: 08/15/2016] [Indexed: 12/21/2022] Open
Abstract
The endocrine role of the skeleton-which is impaired in human diseases including osteoporosis, obesity and diabetes-has been highlighted previously. In these diseases, the role of AMPK, a sensor and regulator of energy metabolism, is of biological and clinical importance. Since AMPK’s main catalytic subunit α has two isoforms, it is unclear whether functional differences between them exist in the skeletal system. The current study overexpressed AMPKα1 and α2 in MC3T3-E1 cells, primary osteoblasts and mouse BMSCs by lentiviral transduction. Cells overexpressing AMPKα2 showed higher osteogenesis potential than AMPKα1, wherein androgen receptor (AR) and osteoactivin played important roles. RANKL and M-CSF were secreted at lower levels from cells overexpressing α2 than α1, resulting in decreased osteoblast-associated osteoclastogenesis. Adipogenesis was inhibited to a greater degree in 3T3-L1 cells overexpressing α2 than α1, which was modulated by AR. An abnormal downregulation of AMPKα2 was observed in human BMSCs exhibiting the fibrous dysplasia (FD) phenotype. Overexpression of AMPKα2 in these cells rescued the defect in osteogenesis, suggesting that AMPKα2 plays a role in FD pathogenesis. These findings highlight functional differences between AMPKα1 and α2, and provide a basis for investigating the molecular mechanisms of diseases associated with impaired functioning of the skeletal system.
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Affiliation(s)
- Yu-Gang Wang
- Shanghai Key Laboratory of Orthopedic Implants, Department of Orthopedic Surgery, Shanghai Ninth People's Hospital, Shanghai JiaoTong University School of Medicine, 639 Zhizaoju Road, Shanghai 200011, People's Republic of China
| | - Xiu-Guo Han
- Shanghai Key Laboratory of Orthopedic Implants, Department of Orthopedic Surgery, Shanghai Ninth People's Hospital, Shanghai JiaoTong University School of Medicine, 639 Zhizaoju Road, Shanghai 200011, People's Republic of China
| | - Ying Yang
- Shanghai Key Laboratory of Orthopedic Implants, Department of Orthopedic Surgery, Shanghai Ninth People's Hospital, Shanghai JiaoTong University School of Medicine, 639 Zhizaoju Road, Shanghai 200011, People's Republic of China
| | - Han Qiao
- Shanghai Key Laboratory of Orthopedic Implants, Department of Orthopedic Surgery, Shanghai Ninth People's Hospital, Shanghai JiaoTong University School of Medicine, 639 Zhizaoju Road, Shanghai 200011, People's Republic of China
| | - Ke-Rong Dai
- Shanghai Key Laboratory of Orthopedic Implants, Department of Orthopedic Surgery, Shanghai Ninth People's Hospital, Shanghai JiaoTong University School of Medicine, 639 Zhizaoju Road, Shanghai 200011, People's Republic of China
| | - Qi-Ming Fan
- Shanghai Key Laboratory of Orthopedic Implants, Department of Orthopedic Surgery, Shanghai Ninth People's Hospital, Shanghai JiaoTong University School of Medicine, 639 Zhizaoju Road, Shanghai 200011, People's Republic of China
| | - Ting-Ting Tang
- Shanghai Key Laboratory of Orthopedic Implants, Department of Orthopedic Surgery, Shanghai Ninth People's Hospital, Shanghai JiaoTong University School of Medicine, 639 Zhizaoju Road, Shanghai 200011, People's Republic of China
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Liu Z, Mohan S, Yakar S. Does the GH/IGF-1 axis contribute to skeletal sexual dimorphism? Evidence from mouse studies. Growth Horm IGF Res 2016; 27:7-17. [PMID: 26843472 PMCID: PMC5488285 DOI: 10.1016/j.ghir.2015.12.004] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/29/2015] [Revised: 11/24/2015] [Accepted: 12/03/2015] [Indexed: 11/22/2022]
Abstract
The contribution of the gonadotropic axis to skeletal sexual dimorphism (SSD) was clarified in recent years. Studies with animal models of estrogen receptor (ER) or androgen receptor (AR) null mice, as well as mice with bone cell-specific ablation of ER or AR, revealed that both hormones play major roles in skeletal acquisition, and that estrogen regulates skeletal accrual in both sexes. The growth hormone (GH) and its downstream effector, the insulin-like growth factor-1 (IGF-1) are also major determinants of peak bone mass during puberty and young adulthood, and play important roles in maintaining bone integrity during aging. A few studies in both humans and animal models suggest that in addition to the differences in sex steroid actions on bone, sex-specific effects of GH and IGF-1 play essential roles in SSD. However, the contributions of the somatotropic (GH/IGF-1) axis to SSD are controversial and data is difficult to interpret. GH/IGF-1 are pleotropic hormones that act in an endocrine and autocrine/paracrine fashion on multiple tissues, affecting body composition as well as metabolism. Thus, understanding the contribution of the somatotropic axis to SSD requires the use of mouse models that will differentiate between these two modes of action. Elucidation of the relative contribution of GH/IGF-1 axis to SSD is significant because GH is approved for the treatment of normal children with short stature and children with congenital growth disorders. Thus, if the GH/IGF-1 axis determines SSD, treatment with GH may be tailored according to sex. In the following review, we give an overview of the roles of sex steroids in determining SSD and how they may interact with the GH/IGF-1 axis in bone. We summarize several mouse models with impaired somatotropic axis and speculate on the possible contribution of that axis to SSD.
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Affiliation(s)
- Zhongbo Liu
- David B. Kriser Dental Center, Department of Basic Science and Craniofacial Biology New York University College of Dentistry New York, NY 10010-408, US
| | - Subburaman Mohan
- Musculoskeletal Disease Center, Loma Linda VA Healthcare Systems, Loma Linda, CA 92357
| | - Shoshana Yakar
- David B. Kriser Dental Center, Department of Basic Science and Craniofacial Biology New York University College of Dentistry New York, NY 10010-408, US.
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Finkelstein JS, Lee H, Leder BZ, Burnett-Bowie SAM, Goldstein DW, Hahn CW, Hirsch SC, Linker A, Perros N, Servais AB, Taylor AP, Webb ML, Youngner JM, Yu EW. Gonadal steroid-dependent effects on bone turnover and bone mineral density in men. J Clin Invest 2016; 126:1114-25. [PMID: 26901812 DOI: 10.1172/jci84137] [Citation(s) in RCA: 113] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2015] [Accepted: 12/10/2015] [Indexed: 01/03/2023] Open
Abstract
BACKGROUND Severe gonadal steroid deficiency induces bone loss in adult men; however, the specific roles of androgen and estrogen deficiency in hypogonadal bone loss are unclear. Additionally, the threshold levels of testosterone and estradiol that initiate bone loss are uncertain. METHODS One hundred ninety-eight healthy men, ages 20-50, received goserelin acetate, which suppresses endogenous gonadal steroid production, and were randomized to treatment with 0, 1.25, 2.5, 5, or 10 grams of testosterone gel daily for 16 weeks. An additional cohort of 202 men was randomized to receive these treatments plus anastrozole, which suppresses conversion of androgens to estrogens. Thirty-seven men served as controls and received placebos for goserelin and testosterone. Changes in bone turnover markers, bone mineral density (BMD) by dual-energy x-ray absorptiometry (DXA), and BMD by quantitative computed tomography (QCT) were assessed in all men. Bone microarchitecture was assessed in 100 men. RESULTS As testosterone dosage decreased, the percent change in C-telopeptide increased. These increases were considerably greater when aromatization of testosterone to estradiol was also suppressed, suggesting effects of both testosterone and estradiol deficiency. Decreases in DXA BMD were observed when aromatization was suppressed but were modest in most groups. QCT spine BMD fell substantially in all testosterone-dose groups in which aromatization was also suppressed, and this decline was independent of testosterone dose. Estradiol deficiency disrupted cortical microarchitecture at peripheral sites. Estradiol levels above 10 pg/ml and testosterone levels above 200 ng/dl were generally sufficient to prevent increases in bone resorption and decreases in BMD in men. CONCLUSIONS Estrogens primarily regulate bone homeostasis in adult men, and testosterone and estradiol levels must decline substantially to impact the skeleton. TRIAL REGISTRATION ClinicalTrials.gov, NCT00114114. FUNDING AbbVie Inc., AstraZeneca Pharmaceuticals LP, NIH.
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Hagberg Thulin M, Nilsson ME, Thulin P, Céraline J, Ohlsson C, Damber JE, Welén K. Osteoblasts promote castration-resistant prostate cancer by altering intratumoral steroidogenesis. Mol Cell Endocrinol 2016; 422:182-191. [PMID: 26586211 DOI: 10.1016/j.mce.2015.11.013] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/03/2015] [Revised: 11/10/2015] [Accepted: 11/10/2015] [Indexed: 11/23/2022]
Abstract
The skeleton is the preferred site for prostate cancer (PC) metastasis leading to incurable castration-resistant disease. The increased expression of genes encoding steroidogenic enzymes found in bone metastatic tissue from patients suggests that up-regulated steroidogenesis might contribute to tumor growth at the metastatic site. Because of the overall sclerotic phenotype, we hypothesize that osteoblasts regulate the intratumoral steroidogenesis of castration resistant prostate cancer (CRPC) in bone. We here show that osteoblasts alter the steroidogenic transcription program in CRPC cells, closely mimicking the gene expression pattern described in CRPC. Osteoblast-stimulated LNCaP-19 cells displayed an increased expression of genes encoding for steroidogenic enzymes (CYP11A1, HSD3B1, and AKR1C3), estrogen signaling-related genes (CYP19A1, and ESR2), and genes for DHT-inactivating enzymes (UGT2B7, UGT2B15, and UGT2B17). The observed osteoblast-induced effect was exclusive to osteogenic CRPC cells (LNCaP-19) in contrast to osteolytic PC-3 and androgen-dependent LNCaP cells. The altered steroid enzymatic pattern was specific for the intratibial tumors and verified by immunohistochemistry in tissue specimens from LNCaP-19 xenograft tumors. Additionally, the overall steroidogenic effect was reflected by corresponding levels of progesterone and testosterone in serum from castrated mice with intratibial xenografts. A bi-directional interplay was demonstrated since both proliferation and Esr2 expression of osteoblasts were induced by CRPC cells in steroid-depleted conditions. Together, our results demonstrate that osteoblasts are important mediators of the intratumoral steroidogenesis of CRPC and for castration-resistant growth in bone. Targeting osteoblasts may therefore be important in the development of new therapeutic approaches.
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Affiliation(s)
- Malin Hagberg Thulin
- Sahlgrenska Cancer Center, Department of Urology, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
| | - Maria E Nilsson
- Center for Bone and Arthritis Research, Department of Internal Medicine and Clinical Nutrition, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Pontus Thulin
- Sahlgrenska Cancer Center, Department of Urology, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Jocelyn Céraline
- INSERM UMR_S 1113, FMTS, Université de Strasbourg, Strasbourg, France
| | - Claes Ohlsson
- Center for Bone and Arthritis Research, Department of Internal Medicine and Clinical Nutrition, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Jan-Erik Damber
- Sahlgrenska Cancer Center, Department of Urology, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Karin Welén
- Sahlgrenska Cancer Center, Department of Urology, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
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Wu J, Movérare-Skrtic S, Börjesson AE, Lagerquist MK, Sjögren K, Windahl SH, Koskela A, Grahnemo L, Islander U, Wilhelmson AS, Tivesten Å, Tuukkanen J, Ohlsson C. Enzalutamide Reduces the Bone Mass in the Axial But Not the Appendicular Skeleton in Male Mice. Endocrinology 2016; 157:969-77. [PMID: 26587782 DOI: 10.1210/en.2015-1566] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Testosterone is a crucial regulator of the skeleton, but the role of the androgen receptor (AR) for the maintenance of the adult male skeleton is unclear. In the present study, the role of the AR for bone metabolism and skeletal growth after sexual maturation was evaluated by means of the drug enzalutamide, which is a new AR antagonist used in the treatment of prostate cancer patients. Nine-week-old male mice were treated with 10, 30, or 100 mg/kg·d of enzalutamide for 21 days or were surgically castrated and were compared with vehicle-treated gonadal intact mice. Although orchidectomy reduced the cortical bone thickness and trabecular bone volume fraction in the appendicular skeleton, these parameters were unaffected by enzalutamide. In contrast, both enzalutamide and orchidectomy reduced the bone mass in the axial skeleton as demonstrated by a reduced lumbar spine areal bone mineral density (P < .001) and trabecular bone volume fraction in L5 vertebrae (P < .001) compared with vehicle-treated gonadal intact mice. A compression test of the L5 vertebrae revealed that the mechanical strength in the axial skeleton was significantly reduced by enzalutamide (maximal load at failure -15.3% ± 3.5%; P < .01). The effects of enzalutamide in the axial skeleton were associated with a high bone turnover. In conclusion, enzalutamide reduces the bone mass in the axial but not the appendicular skeleton in male mice after sexual maturation. We propose that the effect of testosterone on the axial skeleton in male mice is mainly mediated via the AR.
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Affiliation(s)
- Jianyao Wu
- Centre for Bone and Arthritis Research (J.W., S.M.-S., A.E.B., M.K.L., K.S., S.H.W., L.G., U.I., C.O.), Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, S-413 45 Gothenburg, Sweden; Rheumatology and Bone Diseases Unit (A.E.B.), Centre for Genomic and Experimental Medicine, Medical Research Council Institute of Genetics and Molecular Medicine, Western General Hospital, University of Edinburgh, Edinburgh EH4 2XU, Scotland, United Kingdom; Centre for Comparative and Clinical Anatomy (S.H.W.), School of Veterinary Science, University of Bristol, Bristol BS28EJ, United Kingdom; Department of Anatomy and Cell Biology (A.K., J.T.), Medical Research Center, University of Oulu, FI-90014 Oulu, Finland; and The Wallenberg Laboratory for Cardiovascular and Metabolic Research (A.S.W., ÅT.), Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, SE-41345 Gothenburg, Sweden
| | - Sofia Movérare-Skrtic
- Centre for Bone and Arthritis Research (J.W., S.M.-S., A.E.B., M.K.L., K.S., S.H.W., L.G., U.I., C.O.), Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, S-413 45 Gothenburg, Sweden; Rheumatology and Bone Diseases Unit (A.E.B.), Centre for Genomic and Experimental Medicine, Medical Research Council Institute of Genetics and Molecular Medicine, Western General Hospital, University of Edinburgh, Edinburgh EH4 2XU, Scotland, United Kingdom; Centre for Comparative and Clinical Anatomy (S.H.W.), School of Veterinary Science, University of Bristol, Bristol BS28EJ, United Kingdom; Department of Anatomy and Cell Biology (A.K., J.T.), Medical Research Center, University of Oulu, FI-90014 Oulu, Finland; and The Wallenberg Laboratory for Cardiovascular and Metabolic Research (A.S.W., ÅT.), Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, SE-41345 Gothenburg, Sweden
| | - Anna E Börjesson
- Centre for Bone and Arthritis Research (J.W., S.M.-S., A.E.B., M.K.L., K.S., S.H.W., L.G., U.I., C.O.), Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, S-413 45 Gothenburg, Sweden; Rheumatology and Bone Diseases Unit (A.E.B.), Centre for Genomic and Experimental Medicine, Medical Research Council Institute of Genetics and Molecular Medicine, Western General Hospital, University of Edinburgh, Edinburgh EH4 2XU, Scotland, United Kingdom; Centre for Comparative and Clinical Anatomy (S.H.W.), School of Veterinary Science, University of Bristol, Bristol BS28EJ, United Kingdom; Department of Anatomy and Cell Biology (A.K., J.T.), Medical Research Center, University of Oulu, FI-90014 Oulu, Finland; and The Wallenberg Laboratory for Cardiovascular and Metabolic Research (A.S.W., ÅT.), Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, SE-41345 Gothenburg, Sweden
| | - Marie K Lagerquist
- Centre for Bone and Arthritis Research (J.W., S.M.-S., A.E.B., M.K.L., K.S., S.H.W., L.G., U.I., C.O.), Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, S-413 45 Gothenburg, Sweden; Rheumatology and Bone Diseases Unit (A.E.B.), Centre for Genomic and Experimental Medicine, Medical Research Council Institute of Genetics and Molecular Medicine, Western General Hospital, University of Edinburgh, Edinburgh EH4 2XU, Scotland, United Kingdom; Centre for Comparative and Clinical Anatomy (S.H.W.), School of Veterinary Science, University of Bristol, Bristol BS28EJ, United Kingdom; Department of Anatomy and Cell Biology (A.K., J.T.), Medical Research Center, University of Oulu, FI-90014 Oulu, Finland; and The Wallenberg Laboratory for Cardiovascular and Metabolic Research (A.S.W., ÅT.), Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, SE-41345 Gothenburg, Sweden
| | - Klara Sjögren
- Centre for Bone and Arthritis Research (J.W., S.M.-S., A.E.B., M.K.L., K.S., S.H.W., L.G., U.I., C.O.), Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, S-413 45 Gothenburg, Sweden; Rheumatology and Bone Diseases Unit (A.E.B.), Centre for Genomic and Experimental Medicine, Medical Research Council Institute of Genetics and Molecular Medicine, Western General Hospital, University of Edinburgh, Edinburgh EH4 2XU, Scotland, United Kingdom; Centre for Comparative and Clinical Anatomy (S.H.W.), School of Veterinary Science, University of Bristol, Bristol BS28EJ, United Kingdom; Department of Anatomy and Cell Biology (A.K., J.T.), Medical Research Center, University of Oulu, FI-90014 Oulu, Finland; and The Wallenberg Laboratory for Cardiovascular and Metabolic Research (A.S.W., ÅT.), Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, SE-41345 Gothenburg, Sweden
| | - Sara H Windahl
- Centre for Bone and Arthritis Research (J.W., S.M.-S., A.E.B., M.K.L., K.S., S.H.W., L.G., U.I., C.O.), Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, S-413 45 Gothenburg, Sweden; Rheumatology and Bone Diseases Unit (A.E.B.), Centre for Genomic and Experimental Medicine, Medical Research Council Institute of Genetics and Molecular Medicine, Western General Hospital, University of Edinburgh, Edinburgh EH4 2XU, Scotland, United Kingdom; Centre for Comparative and Clinical Anatomy (S.H.W.), School of Veterinary Science, University of Bristol, Bristol BS28EJ, United Kingdom; Department of Anatomy and Cell Biology (A.K., J.T.), Medical Research Center, University of Oulu, FI-90014 Oulu, Finland; and The Wallenberg Laboratory for Cardiovascular and Metabolic Research (A.S.W., ÅT.), Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, SE-41345 Gothenburg, Sweden
| | - Antti Koskela
- Centre for Bone and Arthritis Research (J.W., S.M.-S., A.E.B., M.K.L., K.S., S.H.W., L.G., U.I., C.O.), Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, S-413 45 Gothenburg, Sweden; Rheumatology and Bone Diseases Unit (A.E.B.), Centre for Genomic and Experimental Medicine, Medical Research Council Institute of Genetics and Molecular Medicine, Western General Hospital, University of Edinburgh, Edinburgh EH4 2XU, Scotland, United Kingdom; Centre for Comparative and Clinical Anatomy (S.H.W.), School of Veterinary Science, University of Bristol, Bristol BS28EJ, United Kingdom; Department of Anatomy and Cell Biology (A.K., J.T.), Medical Research Center, University of Oulu, FI-90014 Oulu, Finland; and The Wallenberg Laboratory for Cardiovascular and Metabolic Research (A.S.W., ÅT.), Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, SE-41345 Gothenburg, Sweden
| | - Louise Grahnemo
- Centre for Bone and Arthritis Research (J.W., S.M.-S., A.E.B., M.K.L., K.S., S.H.W., L.G., U.I., C.O.), Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, S-413 45 Gothenburg, Sweden; Rheumatology and Bone Diseases Unit (A.E.B.), Centre for Genomic and Experimental Medicine, Medical Research Council Institute of Genetics and Molecular Medicine, Western General Hospital, University of Edinburgh, Edinburgh EH4 2XU, Scotland, United Kingdom; Centre for Comparative and Clinical Anatomy (S.H.W.), School of Veterinary Science, University of Bristol, Bristol BS28EJ, United Kingdom; Department of Anatomy and Cell Biology (A.K., J.T.), Medical Research Center, University of Oulu, FI-90014 Oulu, Finland; and The Wallenberg Laboratory for Cardiovascular and Metabolic Research (A.S.W., ÅT.), Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, SE-41345 Gothenburg, Sweden
| | - Ulrika Islander
- Centre for Bone and Arthritis Research (J.W., S.M.-S., A.E.B., M.K.L., K.S., S.H.W., L.G., U.I., C.O.), Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, S-413 45 Gothenburg, Sweden; Rheumatology and Bone Diseases Unit (A.E.B.), Centre for Genomic and Experimental Medicine, Medical Research Council Institute of Genetics and Molecular Medicine, Western General Hospital, University of Edinburgh, Edinburgh EH4 2XU, Scotland, United Kingdom; Centre for Comparative and Clinical Anatomy (S.H.W.), School of Veterinary Science, University of Bristol, Bristol BS28EJ, United Kingdom; Department of Anatomy and Cell Biology (A.K., J.T.), Medical Research Center, University of Oulu, FI-90014 Oulu, Finland; and The Wallenberg Laboratory for Cardiovascular and Metabolic Research (A.S.W., ÅT.), Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, SE-41345 Gothenburg, Sweden
| | - Anna S Wilhelmson
- Centre for Bone and Arthritis Research (J.W., S.M.-S., A.E.B., M.K.L., K.S., S.H.W., L.G., U.I., C.O.), Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, S-413 45 Gothenburg, Sweden; Rheumatology and Bone Diseases Unit (A.E.B.), Centre for Genomic and Experimental Medicine, Medical Research Council Institute of Genetics and Molecular Medicine, Western General Hospital, University of Edinburgh, Edinburgh EH4 2XU, Scotland, United Kingdom; Centre for Comparative and Clinical Anatomy (S.H.W.), School of Veterinary Science, University of Bristol, Bristol BS28EJ, United Kingdom; Department of Anatomy and Cell Biology (A.K., J.T.), Medical Research Center, University of Oulu, FI-90014 Oulu, Finland; and The Wallenberg Laboratory for Cardiovascular and Metabolic Research (A.S.W., ÅT.), Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, SE-41345 Gothenburg, Sweden
| | - Åsa Tivesten
- Centre for Bone and Arthritis Research (J.W., S.M.-S., A.E.B., M.K.L., K.S., S.H.W., L.G., U.I., C.O.), Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, S-413 45 Gothenburg, Sweden; Rheumatology and Bone Diseases Unit (A.E.B.), Centre for Genomic and Experimental Medicine, Medical Research Council Institute of Genetics and Molecular Medicine, Western General Hospital, University of Edinburgh, Edinburgh EH4 2XU, Scotland, United Kingdom; Centre for Comparative and Clinical Anatomy (S.H.W.), School of Veterinary Science, University of Bristol, Bristol BS28EJ, United Kingdom; Department of Anatomy and Cell Biology (A.K., J.T.), Medical Research Center, University of Oulu, FI-90014 Oulu, Finland; and The Wallenberg Laboratory for Cardiovascular and Metabolic Research (A.S.W., ÅT.), Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, SE-41345 Gothenburg, Sweden
| | - Juha Tuukkanen
- Centre for Bone and Arthritis Research (J.W., S.M.-S., A.E.B., M.K.L., K.S., S.H.W., L.G., U.I., C.O.), Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, S-413 45 Gothenburg, Sweden; Rheumatology and Bone Diseases Unit (A.E.B.), Centre for Genomic and Experimental Medicine, Medical Research Council Institute of Genetics and Molecular Medicine, Western General Hospital, University of Edinburgh, Edinburgh EH4 2XU, Scotland, United Kingdom; Centre for Comparative and Clinical Anatomy (S.H.W.), School of Veterinary Science, University of Bristol, Bristol BS28EJ, United Kingdom; Department of Anatomy and Cell Biology (A.K., J.T.), Medical Research Center, University of Oulu, FI-90014 Oulu, Finland; and The Wallenberg Laboratory for Cardiovascular and Metabolic Research (A.S.W., ÅT.), Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, SE-41345 Gothenburg, Sweden
| | - Claes Ohlsson
- Centre for Bone and Arthritis Research (J.W., S.M.-S., A.E.B., M.K.L., K.S., S.H.W., L.G., U.I., C.O.), Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, S-413 45 Gothenburg, Sweden; Rheumatology and Bone Diseases Unit (A.E.B.), Centre for Genomic and Experimental Medicine, Medical Research Council Institute of Genetics and Molecular Medicine, Western General Hospital, University of Edinburgh, Edinburgh EH4 2XU, Scotland, United Kingdom; Centre for Comparative and Clinical Anatomy (S.H.W.), School of Veterinary Science, University of Bristol, Bristol BS28EJ, United Kingdom; Department of Anatomy and Cell Biology (A.K., J.T.), Medical Research Center, University of Oulu, FI-90014 Oulu, Finland; and The Wallenberg Laboratory for Cardiovascular and Metabolic Research (A.S.W., ÅT.), Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, SE-41345 Gothenburg, Sweden
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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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Di Nisio A, De Toni L, Speltra E, Rocca MS, Taglialavoro G, Ferlin A, Foresta C. Regulation of Sclerostin Production in Human Male Osteocytes by Androgens: Experimental and Clinical Evidence. Endocrinology 2015; 156:4534-44. [PMID: 26393301 DOI: 10.1210/en.2015-1244] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
In this study we aimed to elucidate a possible role of T in the regulation of sclerostin, a glycoprotein secreted by osteocytes known to regulate bone mass. To this end, we evaluated the effect of T stimulation on sclerostin production and gene expression in human cultured osteocytes. In addition, we evaluated serum sclerostin levels in a cohort of 20 hypogonadal male patients, compared with 20 age-matched eugonadal controls. Stimulation with DHT decreased sclerostin expression in cultured osteocytes in a time- and dose-dependent manner. Confirming a direct androgen receptor-mediated effect on sclerostin production, flutamide coincubation and silencing of androgen receptor gene in osteocytes abolished the DHT effects. In addition, hypogonadal patients showed higher serum sclerostin levels with respect to controls (145.87 ± 50.83 pg/mL vs 84.02 ± 32.15 pg/mL; P < .001) and in both probands and controls, serum T levels were negatively correlated with sclerostin (R = -0.664, P = 0.007, and R = -0.447, P = .045, respectively). Finally, multiple stepwise regression analysis showed that T represented the only independent predictor of sclerostin levels. In conclusion, by showing a direct correlation between T and sclerostin, both in vivo and in vitro, this study adds further support to the emerging clinical and experimental studies focusing on sclerostin as a therapeutic target for osteoporosis treatment.
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Affiliation(s)
- Andrea Di Nisio
- Department of Medicine (A.D.N., L.D.T., E.S., M.S.R., A.F., C.F.), Operative Unit of Andrology and Medicine of Human Reproduction, and Department of Surgical, Oncological, and Gastroenterological Sciences (G.T.), University of Padova, 35128 Padova, Italy
| | - Luca De Toni
- Department of Medicine (A.D.N., L.D.T., E.S., M.S.R., A.F., C.F.), Operative Unit of Andrology and Medicine of Human Reproduction, and Department of Surgical, Oncological, and Gastroenterological Sciences (G.T.), University of Padova, 35128 Padova, Italy
| | - Elena Speltra
- Department of Medicine (A.D.N., L.D.T., E.S., M.S.R., A.F., C.F.), Operative Unit of Andrology and Medicine of Human Reproduction, and Department of Surgical, Oncological, and Gastroenterological Sciences (G.T.), University of Padova, 35128 Padova, Italy
| | - Maria Santa Rocca
- Department of Medicine (A.D.N., L.D.T., E.S., M.S.R., A.F., C.F.), Operative Unit of Andrology and Medicine of Human Reproduction, and Department of Surgical, Oncological, and Gastroenterological Sciences (G.T.), University of Padova, 35128 Padova, Italy
| | - Giuseppe Taglialavoro
- Department of Medicine (A.D.N., L.D.T., E.S., M.S.R., A.F., C.F.), Operative Unit of Andrology and Medicine of Human Reproduction, and Department of Surgical, Oncological, and Gastroenterological Sciences (G.T.), University of Padova, 35128 Padova, Italy
| | - Alberto Ferlin
- Department of Medicine (A.D.N., L.D.T., E.S., M.S.R., A.F., C.F.), Operative Unit of Andrology and Medicine of Human Reproduction, and Department of Surgical, Oncological, and Gastroenterological Sciences (G.T.), University of Padova, 35128 Padova, Italy
| | - Carlo Foresta
- Department of Medicine (A.D.N., L.D.T., E.S., M.S.R., A.F., C.F.), Operative Unit of Andrology and Medicine of Human Reproduction, and Department of Surgical, Oncological, and Gastroenterological Sciences (G.T.), University of Padova, 35128 Padova, Italy
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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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Clarke MV, Russell PK, Findlay DM, Sastra S, Anderson PH, Skinner JP, Atkins GJ, Zajac JD, Davey RA. A Role for the Calcitonin Receptor to Limit Bone Loss During Lactation in Female Mice by Inhibiting Osteocytic Osteolysis. Endocrinology 2015; 156:3203-14. [PMID: 26135836 DOI: 10.1210/en.2015-1345] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
During lactation, the large transfer of calcium from the mother to the milk is primarily sourced from the maternal skeleton. To determine whether the calcitonin receptor (CTR) plays a physiological role to protect the skeleton from excessive resorption during lactation, we assessed the maternal skeleton of global CTR knockout (CTRKO) and littermate control mice at the end of lactation (postnatal day 21). Micro-computed tomography analyses showed no effect on trabecular or cortical bone in the distal femur and L1 vertebra of maternal global CTR deletion at the end of lactation in global CTRKO mice compared with that in control mice. Bone resorption, as assessed by osteoclast number and activity at the end of lactation, was unaffected by maternal CTR deletion. Cathepsin K, carbonic anhydrase 2, matrix metalloproteinase 13, and receptor activator of nuclear factor-κB ligand mRNA levels, however, were markedly elevated by 3- to 6.5-fold in whole bone of lactating global CTRKO females. Because these genes have been shown to be up-regulated in osteocytes during lactation when osteocytes resorb their surrounding bone matrix, together with their reported expression of the CTR, we determined the osteocyte lacunar area in cortical bone. After lactation, the top 20% of osteocyte lacunar area in global CTRKO mice was 10% larger than the top 20% in control mice. These data are consistent with an increased osteocytic osteolysis in global CTRKO mice during lactation, which is further supported by the increased serum calcium observed in global CTRKO mice after lactation. These results provide evidence for a physiological role for the CTR to protect the maternal skeleton during lactation by a direct action on osteocytes to inhibit osteolysis.
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Affiliation(s)
- Michele V Clarke
- Department of Medicine (M.V.C., P.K.R., S.S., J.P.S., J.D.Z., R.A.D.), Austin Health, University of Melbourne, Heidelberg, 3084 Victoria, Australia; Centre for Orthopaedic and Trauma Research (D.M.F., G.J.A.), University of Adelaide, 5005 Adelaide, Australia; and School of Pharmacy and Medical Sciences (P.H.A.), University of South Australia, 5005 Adelaide, Australia
| | - Patricia K Russell
- Department of Medicine (M.V.C., P.K.R., S.S., J.P.S., J.D.Z., R.A.D.), Austin Health, University of Melbourne, Heidelberg, 3084 Victoria, Australia; Centre for Orthopaedic and Trauma Research (D.M.F., G.J.A.), University of Adelaide, 5005 Adelaide, Australia; and School of Pharmacy and Medical Sciences (P.H.A.), University of South Australia, 5005 Adelaide, Australia
| | - David M Findlay
- Department of Medicine (M.V.C., P.K.R., S.S., J.P.S., J.D.Z., R.A.D.), Austin Health, University of Melbourne, Heidelberg, 3084 Victoria, Australia; Centre for Orthopaedic and Trauma Research (D.M.F., G.J.A.), University of Adelaide, 5005 Adelaide, Australia; and School of Pharmacy and Medical Sciences (P.H.A.), University of South Australia, 5005 Adelaide, Australia
| | - Stephen Sastra
- Department of Medicine (M.V.C., P.K.R., S.S., J.P.S., J.D.Z., R.A.D.), Austin Health, University of Melbourne, Heidelberg, 3084 Victoria, Australia; Centre for Orthopaedic and Trauma Research (D.M.F., G.J.A.), University of Adelaide, 5005 Adelaide, Australia; and School of Pharmacy and Medical Sciences (P.H.A.), University of South Australia, 5005 Adelaide, Australia
| | - Paul H Anderson
- Department of Medicine (M.V.C., P.K.R., S.S., J.P.S., J.D.Z., R.A.D.), Austin Health, University of Melbourne, Heidelberg, 3084 Victoria, Australia; Centre for Orthopaedic and Trauma Research (D.M.F., G.J.A.), University of Adelaide, 5005 Adelaide, Australia; and School of Pharmacy and Medical Sciences (P.H.A.), University of South Australia, 5005 Adelaide, Australia
| | - Jarrod P Skinner
- Department of Medicine (M.V.C., P.K.R., S.S., J.P.S., J.D.Z., R.A.D.), Austin Health, University of Melbourne, Heidelberg, 3084 Victoria, Australia; Centre for Orthopaedic and Trauma Research (D.M.F., G.J.A.), University of Adelaide, 5005 Adelaide, Australia; and School of Pharmacy and Medical Sciences (P.H.A.), University of South Australia, 5005 Adelaide, Australia
| | - Gerald J Atkins
- Department of Medicine (M.V.C., P.K.R., S.S., J.P.S., J.D.Z., R.A.D.), Austin Health, University of Melbourne, Heidelberg, 3084 Victoria, Australia; Centre for Orthopaedic and Trauma Research (D.M.F., G.J.A.), University of Adelaide, 5005 Adelaide, Australia; and School of Pharmacy and Medical Sciences (P.H.A.), University of South Australia, 5005 Adelaide, Australia
| | - Jeffrey D Zajac
- Department of Medicine (M.V.C., P.K.R., S.S., J.P.S., J.D.Z., R.A.D.), Austin Health, University of Melbourne, Heidelberg, 3084 Victoria, Australia; Centre for Orthopaedic and Trauma Research (D.M.F., G.J.A.), University of Adelaide, 5005 Adelaide, Australia; and School of Pharmacy and Medical Sciences (P.H.A.), University of South Australia, 5005 Adelaide, Australia
| | - Rachel A Davey
- Department of Medicine (M.V.C., P.K.R., S.S., J.P.S., J.D.Z., R.A.D.), Austin Health, University of Melbourne, Heidelberg, 3084 Victoria, Australia; Centre for Orthopaedic and Trauma Research (D.M.F., G.J.A.), University of Adelaide, 5005 Adelaide, Australia; and School of Pharmacy and Medical Sciences (P.H.A.), University of South Australia, 5005 Adelaide, Australia
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Sinnesael M, Jardi F, Deboel L, Laurent MR, Dubois V, Zajac JD, Davey RA, Carmeliet G, Claessens F, Vanderschueren D. The androgen receptor has no direct antiresorptive actions in mouse osteoclasts. Mol Cell Endocrinol 2015; 411:198-206. [PMID: 25958043 DOI: 10.1016/j.mce.2015.04.030] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/13/2015] [Revised: 04/29/2015] [Accepted: 04/29/2015] [Indexed: 12/31/2022]
Abstract
Androgen deficiency or androgen receptor knockout (ARKO) causes high-turnover osteopenia, but the target cells for this effect remain unclear. To examine whether AR in osteoclasts directly suppresses bone resorption, we crossed AR-floxed with cathepsin K-Cre mice. Osteoclast-specific ARKO (ocl-ARKO) mice showed no changes neither in osteoclast surface nor in bone microarchitecture nor in the response to orchidectomy and androgen replacement, indicating that the AR in osteoclasts is not critical for bone maintenance. In line with the lack of a bone phenotype, the levels of AR were very low in osteoclast-enriched cultures derived from bone marrow (BM) and undetectable in osteoclasts generated from spleen precursors. Since tibiae of ubiquitous ARKO mice displayed increased osteoclast counts, the role of AR was further explored using cell cultures from these animals. Osteoclast generation and activity in vitro were similar between ARKO and wildtype control (WT) mice. In co-culture experiments, BM stromal cells (BMSCs) were essential for the suppressive action of AR on osteoclastogenesis and osteoclast activity. Stimulation with 1,25(OH)2 vitamin D3 increased Rankl and decreased Tnfsf11 (osteoprotegerin, Opg) gene expression in BMSCs more than in osteoblasts. This increase in the Rankl/Opg ratio following 1,25(OH)2D3 stimulation was lower, not higher, in ARKO mice. Runx2 expression in BMSCs was however higher in ARKO vs. WT, suggesting that ARKO mice may more readily commit osteoprogenitor cells to osteoblastogenesis. In conclusion, the AR does not seem to suppress bone resorption through direct actions in osteoclasts. BMSCs may however represent an alternative AR target in the BM milieu.
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Affiliation(s)
- Mieke Sinnesael
- Clinical and Experimental Endocrinology, Department of Clinical and Experimental Medicine, KU Leuven, Leuven, Belgium
| | - Ferran Jardi
- Clinical and Experimental Endocrinology, Department of Clinical and Experimental Medicine, KU Leuven, Leuven, Belgium
| | - Ludo Deboel
- Clinical and Experimental Endocrinology, Department of Clinical and Experimental Medicine, KU Leuven, Leuven, Belgium
| | - Michaël R Laurent
- Molecular Endocrinology Laboratory, Department of Cellular and Molecular Medicine, KU Leuven, Leuven, Belgium; Gerontology and Geriatrics, Department of Clinical and Experimental Medicine, KU Leuven, Leuven, Belgium
| | - Vanessa Dubois
- Molecular Endocrinology Laboratory, Department of Cellular and Molecular Medicine, KU Leuven, Leuven, Belgium
| | - Jeffrey D Zajac
- Department of Medicine, Austin Health, University of Melbourne, Heidelberg, Victoria, Australia
| | - Rachel A Davey
- Department of Medicine, Austin Health, University of Melbourne, Heidelberg, Victoria, Australia
| | - Geert Carmeliet
- Clinical and Experimental Endocrinology, Department of Clinical and Experimental Medicine, KU Leuven, Leuven, Belgium
| | - Frank Claessens
- Molecular Endocrinology Laboratory, Department of Cellular and Molecular Medicine, KU Leuven, Leuven, Belgium
| | - Dirk Vanderschueren
- Clinical and Experimental Endocrinology, Department of Clinical and Experimental Medicine, KU Leuven, Leuven, Belgium.
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Ucer S, Iyer S, Bartell SM, Martin-Millan M, Han L, Kim HN, Weinstein RS, Jilka RL, O'Brien CA, Almeida M, Manolagas SC. The Effects of Androgens on Murine Cortical Bone Do Not Require AR or ERα Signaling in Osteoblasts and Osteoclasts. J Bone Miner Res 2015; 30:1138-49. [PMID: 25704845 PMCID: PMC4871247 DOI: 10.1002/jbmr.2485] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/24/2014] [Revised: 01/30/2015] [Accepted: 02/17/2015] [Indexed: 12/14/2022]
Abstract
In men, androgens are critical for the acquisition and maintenance of bone mass in both the cortical and cancellous bone compartment. Male mice with targeted deletion of the androgen receptor (AR) in mature osteoblasts or osteocytes have lower cancellous bone mass, but no cortical bone phenotype. We have investigated the possibility that the effects of androgens on the cortical compartment result from AR signaling in osteoprogenitors or cells of the osteoclast lineage; or via estrogen receptor alpha (ERα) signaling in either or both of these two cell types upon conversion of testosterone to estradiol. To this end, we generated mice with targeted deletion of an AR or an ERα allele in the mesenchymal (AR(f/y);Prx1-Cre or ERα(f/f);Osx1-Cre) or myeloid cell lineage (AR(f/y);LysM-Cre or ERα(f/f);LysM-Cre) and their descendants. Male AR(f/y);Prx1-Cre mice exhibited decreased bone volume and trabecular number, and increased osteoclast number in the cancellous compartment. Moreover, they did not undergo the loss of cancellous bone volume and trabecular number caused by orchidectomy (ORX) in their littermate controls. In contrast, AR(f/y);LysM-Cre, ERα(f/f);Osx1-Cre, or ERα(f/f);LysM-Cre mice had no cancellous bone phenotype at baseline and lost the same amount of cancellous bone as their controls following ORX. Most unexpectedly, adult males of all four models had no discernible cortical bone phenotype at baseline, and lost the same amount of cortical bone as their littermate controls after ORX. Recapitulation of the effects of ORX by AR deletion only in the AR(f/y);Prx1-Cre mice indicates that the effects of androgens on cancellous bone result from AR signaling in osteoblasts-not on osteoclasts or via aromatization. The effects of androgens on cortical bone mass, on the other hand, do not require AR or ERα signaling in any cell type across the osteoblast or osteoclast differentiation lineage. Therefore, androgens must exert their effects indirectly by actions on some other cell type(s) or tissue(s).
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Affiliation(s)
- Serra Ucer
- 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
| | - Srividhya Iyer
- 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
| | - Shoshana M Bartell
- 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
| | - Marta Martin-Millan
- 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
| | - Li Han
- 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
| | - Ha-Neui Kim
- 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
| | - Robert S Weinstein
- 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
| | - Robert L Jilka
- 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
| | - 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, AR, USA
| | - 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, AR, 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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Khosla S. New Insights Into Androgen and Estrogen Receptor Regulation of the Male Skeleton. J Bone Miner Res 2015; 30:1134-7. [PMID: 25857392 PMCID: PMC4758667 DOI: 10.1002/jbmr.2529] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/25/2015] [Revised: 04/02/2015] [Accepted: 04/04/2015] [Indexed: 12/17/2022]
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Russell PK, Clarke MV, Cheong K, Anderson PH, Morris HA, Wiren KM, Zajac JD, Davey RA. Androgen receptor action in osteoblasts in male mice is dependent on their stage of maturation. J Bone Miner Res 2015; 30:809-23. [PMID: 25407961 DOI: 10.1002/jbmr.2413] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/08/2014] [Revised: 11/12/2014] [Accepted: 11/14/2014] [Indexed: 11/10/2022]
Abstract
Androgen action via the androgen receptor (AR) is essential for normal skeletal growth and bone maintenance post-puberty in males; however, the molecular and cellular mechanisms by which androgens exert their actions in osteoblasts remains relatively unexplored in vivo. To identify autonomous AR actions in osteoblasts independent of AR signaling in other tissues, we compared the extent to which the bone phenotype of the Global-ARKO mouse was restored by replacing the AR in osteoblasts commencing at either the (1) proliferative or (2) mineralization stage of their maturation. In trabecular bone, androgens stimulated trabecular bone accrual during growth via the AR in proliferating osteoblasts and maintained trabecular bone post-puberty via the AR in mineralizing osteoblasts, with its predominant action being to inhibit bone resorption by decreasing the ratio of receptor activator of NF-κB ligand (RANKL) to osteoprotegerin (OPG) gene expression. During growth, replacement of the AR in proliferating but not mineralizing osteoblasts of Global-ARKOs was able to partially restore periosteal circumference, supporting the concept that androgen action in cortical bone to increase bone size during growth is mediated via the AR in proliferating osteoblasts. This study provides further significant insight into the mechanism of androgen action via the AR in osteoblasts, demonstrating that it is dependent on the stage of osteoblast maturation.
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Affiliation(s)
- Patricia K Russell
- Department of Medicine, Austin Health, University of Melbourne, Heidelberg, Australia
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Hendrickx G, Boudin E, Van Hul W. A look behind the scenes: the risk and pathogenesis of primary osteoporosis. Nat Rev Rheumatol 2015; 11:462-74. [PMID: 25900210 DOI: 10.1038/nrrheum.2015.48] [Citation(s) in RCA: 165] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Osteoporosis is a common disorder, affecting hundreds of millions of people worldwide, and characterized by decreased bone mineral density and increased fracture risk. Known nonheritable risk factors for primary osteoporosis include advanced age, sex-steroid deficiency and increased oxidative stress. Age is a nonmodifiable risk factor, but the influence of a person's lifestyle (diet and physical activity) on their bone structure and density is modifiable to some extent. Heritable factors influencing bone fragility can be monogenic or polygenic. Osteogenesis imperfecta, juvenile osteoporosis and syndromes of decreased bone density are discussed as examples of monogenic disorders associated with bone fragility. So far, the factors associated with polygenic osteoporosis have been investigated mainly in genome-wide association studies. However, epigenetic mechanisms also contribute to the heritability of polygenic osteoporosis. Identification of these heritable and nonheritable risk factors has already led to the discovery of therapeutic targets for osteoporosis, which emphasizes the importance of research into the pathogenetic mechanisms of osteoporosis. Accordingly, this article discusses the many heritable and nonheritable factors that contribute to the pathogenesis of primary osteoporosis. Although osteoporosis can also develop secondary to many other diseases or their treatment, a discussion of the factors that contribute only to secondary osteoporosis is beyond the scope of this Review.
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Affiliation(s)
- Gretl Hendrickx
- Department of Medical Genetics, University of Antwerp, Prins Boudewijnlaan 43B, 2650 Edegem, Belgium
| | - Eveline Boudin
- Department of Medical Genetics, University of Antwerp, Prins Boudewijnlaan 43B, 2650 Edegem, Belgium
| | - Wim Van Hul
- Department of Medical Genetics, University of Antwerp, Prins Boudewijnlaan 43B, 2650 Edegem, Belgium
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Jin Z, Li X, Wan Y. Minireview: nuclear receptor regulation of osteoclast and bone remodeling. Mol Endocrinol 2014; 29:172-86. [PMID: 25549044 DOI: 10.1210/me.2014-1316] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Osteoclasts are bone-resorbing cells essential for skeletal remodeling and regeneration. However, excessive osteoclasts often contribute to prevalent bone degenerative diseases such as osteoporosis, arthritis, and cancer bone metastasis. Osteoclast dysregulation is also associated with rare disorders such as osteopetrosis, pycnodysostosis, Paget's disease, and Gorham-Stout syndrome. The nuclear receptor (NR) family of transcription factors functions as metabolic sensors that control a variety of physiological processes including skeletal homeostasis and serves as attractive therapeutic targets for many diseases. In this review, we highlight recent findings on the new players and the new mechanisms for how NRs regulate osteoclast differentiation and bone resorption. An enhanced understanding of NR functions in osteoclastogenesis will facilitate the development of not only novel osteoprotective medicine but also prudent strategies to minimize the adverse skeletal effects of certain NR-targeting drugs for a better treatment of cancer and metabolic diseases.
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Affiliation(s)
- Zixue Jin
- Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, Texas 75390
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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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