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Hu X, Wang Z, Wang W, Cui P, Kong C, Chen X, Lu S. Irisin as an agent for protecting against osteoporosis: A review of the current mechanisms and pathways. J Adv Res 2024; 62:175-186. [PMID: 37669714 DOI: 10.1016/j.jare.2023.09.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2023] [Revised: 08/24/2023] [Accepted: 09/01/2023] [Indexed: 09/07/2023] Open
Abstract
BACKGROUND Osteoporosis is recognized as a skeletal disorder characterized by diminished bone tissue quality and density. Regular physical exercise is widely acknowledged to preserve and enhance bone health, but the detailed molecular mechanisms involved remain unclear. Irisin, a factor derived from muscle during exercise, influences bone and muscle. Since its discovery in 2012, irisin has been found to promote bone growth and reduce bone resorption, establishing a tangible link between muscle exertion and bone health. Consequently, the mechanism by which irisin prevents osteoporosis have attracted significant scientific interest. AIM OF THE REVIEW This study aims to elucidate the multifaceted relationship between exercise, irisin, and bone health. Focusing on irisin, a muscle-derived factor released during exercise, we seek to understand its role in promoting bone growth and inhibiting resorption. Through a review of current research article on irisin in osteoporosis, Our review provides a deep dive into existing research on influence of irisin in osteoporosis, exploring its interaction with pivotal signaling pathways and its impact on various cell death mechanisms and inflammation. We aim to uncover the molecular underpinnings of how irisin, secreted during exercise, can serve as a therapeutic strategy for osteoporosis. KEY SCIENTIFIC CONCEPTS OF THE REVIEW Irisin, secreted during exercise, plays a vital role in bridging muscle function to bone health. It not only promotes bone growth but also inhibits bone resorption. Specifically, Irisin fosters osteoblast proliferation, differentiation, and mineralization predominantly through the ERK, p38, and AMPK signaling pathways. Concurrently, it regulates osteoclast differentiation and maturation via the JNK, Wnt/β-catenin and RANKL/RANK/OPG signaling pathways. This review further delves into the profound significance of irisin in osteoporosis and its involvement in diverse cellular death mechanisms, including apoptosis, autophagy, ferroptosis, and pyroptosis.
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Affiliation(s)
- Xinli Hu
- Department of Orthopedics, Xuanwu Hospital, Capital Medical University, No.45 Changchun Street, Xicheng District, Beijing 100053, China; National Clinical Research Center for Geriatric Diseases, Xuanwu Hospital, Capital Medical University, Beijing 100053, China
| | - Zheng Wang
- Department of Orthopedics, Xuanwu Hospital, Capital Medical University, No.45 Changchun Street, Xicheng District, Beijing 100053, China; National Clinical Research Center for Geriatric Diseases, Xuanwu Hospital, Capital Medical University, Beijing 100053, China
| | - Wei Wang
- Department of Orthopedics, Xuanwu Hospital, Capital Medical University, No.45 Changchun Street, Xicheng District, Beijing 100053, China; National Clinical Research Center for Geriatric Diseases, Xuanwu Hospital, Capital Medical University, Beijing 100053, China
| | - Peng Cui
- Department of Orthopedics, Xuanwu Hospital, Capital Medical University, No.45 Changchun Street, Xicheng District, Beijing 100053, China; National Clinical Research Center for Geriatric Diseases, Xuanwu Hospital, Capital Medical University, Beijing 100053, China
| | - Chao Kong
- Department of Orthopedics, Xuanwu Hospital, Capital Medical University, No.45 Changchun Street, Xicheng District, Beijing 100053, China; National Clinical Research Center for Geriatric Diseases, Xuanwu Hospital, Capital Medical University, Beijing 100053, China.
| | - Xiaolong Chen
- Department of Orthopedics, Xuanwu Hospital, Capital Medical University, No.45 Changchun Street, Xicheng District, Beijing 100053, China; National Clinical Research Center for Geriatric Diseases, Xuanwu Hospital, Capital Medical University, Beijing 100053, China.
| | - Shibao Lu
- Department of Orthopedics, Xuanwu Hospital, Capital Medical University, No.45 Changchun Street, Xicheng District, Beijing 100053, China; National Clinical Research Center for Geriatric Diseases, Xuanwu Hospital, Capital Medical University, Beijing 100053, China.
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Angelozzi M, Karvande A, Lefebvre V. SOXC are critical regulators of adult bone mass. Nat Commun 2024; 15:2956. [PMID: 38580651 PMCID: PMC10997656 DOI: 10.1038/s41467-024-47413-2] [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: 09/08/2023] [Accepted: 03/28/2024] [Indexed: 04/07/2024] Open
Abstract
Pivotal in many ways for human health, the control of adult bone mass is governed by complex, incompletely understood crosstalk namely between mesenchymal stem cells, osteoblasts and osteoclasts. The SOX4, SOX11 and SOX12 (SOXC) transcription factors were previously shown to control many developmental processes, including skeletogenesis, and SOX4 was linked to osteoporosis, but how SOXC control adult bone mass remains unknown. Using SOXC loss- and gain-of-function mouse models, we show here that SOXC redundantly promote prepubertal cortical bone mass strengthening whereas only SOX4 mitigates adult trabecular bone mass accrual in early adulthood and subsequent maintenance. SOX4 favors bone resorption over formation by lowering osteoblastogenesis and increasing osteoclastogenesis. Single-cell transcriptomics reveals its prevalent expression in Lepr+ mesenchymal cells and ability to upregulate genes for prominent anti-osteoblastogenic and pro-osteoclastogenic factors, including interferon signaling-related chemokines, contributing to these adult stem cells' secretome. SOXC, with SOX4 predominantly, are thus key regulators of adult bone mass.
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Affiliation(s)
- Marco Angelozzi
- Department of Surgery, Division of Orthopaedics, Children's Hospital of Philadelphia, Philadelphia, PA, USA.
| | - Anirudha Karvande
- Department of Surgery, Division of Orthopaedics, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Véronique Lefebvre
- Department of Surgery, Division of Orthopaedics, Children's Hospital of Philadelphia, Philadelphia, PA, USA.
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Romero-Márquez JM, Varela-López A, Navarro-Hortal MD, Badillo-Carrasco A, Forbes-Hernández TY, Giampieri F, Domínguez I, Madrigal L, Battino M, Quiles JL. Molecular Interactions between Dietary Lipids and Bone Tissue during Aging. Int J Mol Sci 2021; 22:ijms22126473. [PMID: 34204176 PMCID: PMC8233828 DOI: 10.3390/ijms22126473] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Revised: 06/09/2021] [Accepted: 06/11/2021] [Indexed: 01/06/2023] Open
Abstract
Age-related bone disorders such as osteoporosis or osteoarthritis are a major public health problem due to the functional disability for millions of people worldwide. Furthermore, fractures are associated with a higher degree of morbidity and mortality in the long term, which generates greater financial and health costs. As the world population becomes older, the incidence of this type of disease increases and this effect seems notably greater in those countries that present a more westernized lifestyle. Thus, increased efforts are directed toward reducing risks that need to focus not only on the prevention of bone diseases, but also on the treatment of persons already afflicted. Evidence is accumulating that dietary lipids play an important role in bone health which results relevant to develop effective interventions for prevent bone diseases or alterations, especially in the elderly segment of the population. This review focuses on evidence about the effects of dietary lipids on bone health and describes possible mechanisms to explain how lipids act on bone metabolism during aging. Little work, however, has been accomplished in humans, so this is a challenge for future research.
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Affiliation(s)
- Jose M. Romero-Márquez
- Department of Physiology, Institute of Nutrition and Food Technology ‘‘José Mataix”, Biomedical Research Centre, University of Granada, Armilla, Avda. del Conocimiento s.n., 18100 Armilla, Spain; (J.M.R.-M.); (A.V.-L.); (M.D.N.-H.); (A.B.-C.)
| | - Alfonso Varela-López
- Department of Physiology, Institute of Nutrition and Food Technology ‘‘José Mataix”, Biomedical Research Centre, University of Granada, Armilla, Avda. del Conocimiento s.n., 18100 Armilla, Spain; (J.M.R.-M.); (A.V.-L.); (M.D.N.-H.); (A.B.-C.)
| | - María D. Navarro-Hortal
- Department of Physiology, Institute of Nutrition and Food Technology ‘‘José Mataix”, Biomedical Research Centre, University of Granada, Armilla, Avda. del Conocimiento s.n., 18100 Armilla, Spain; (J.M.R.-M.); (A.V.-L.); (M.D.N.-H.); (A.B.-C.)
| | - Alberto Badillo-Carrasco
- Department of Physiology, Institute of Nutrition and Food Technology ‘‘José Mataix”, Biomedical Research Centre, University of Granada, Armilla, Avda. del Conocimiento s.n., 18100 Armilla, Spain; (J.M.R.-M.); (A.V.-L.); (M.D.N.-H.); (A.B.-C.)
| | - Tamara Y. Forbes-Hernández
- Nutrition and Food Science Group, Department of Analytical and Food Chemistry, CITACA, CACTI, University of Vigo, 36310 Vigo, Spain;
| | - Francesca Giampieri
- Department of Clinical Sicences, Università Politecnica delle Marche, 60131 Ancona, Italy; (F.G.); (M.B.)
- Department of Biochemistry, Faculty of Sciences, King Abdulaziz University, Jeddah 21589, Saudi Arabia
| | - Irma Domínguez
- Research Group on Foods, Nutritional Biochemistry and Health, Universidad Europea del Atlántico, Isabel Torres 21, 39011 Santander, Spain;
- Universidad Internacional Iberoamericana, Calle 15 Num. 36, Entre 10 y 12 IMI III, Campeche 24560, Mexico;
| | - Lorena Madrigal
- Universidad Internacional Iberoamericana, Calle 15 Num. 36, Entre 10 y 12 IMI III, Campeche 24560, Mexico;
| | - Maurizio Battino
- Department of Clinical Sicences, Università Politecnica delle Marche, 60131 Ancona, Italy; (F.G.); (M.B.)
- International Research Center for Food Nutrition and Safety, Jiangsu University, Zhenjiang 212013, China
| | - José L. Quiles
- Department of Physiology, Institute of Nutrition and Food Technology ‘‘José Mataix”, Biomedical Research Centre, University of Granada, Armilla, Avda. del Conocimiento s.n., 18100 Armilla, Spain; (J.M.R.-M.); (A.V.-L.); (M.D.N.-H.); (A.B.-C.)
- Research Group on Foods, Nutritional Biochemistry and Health, Universidad Europea del Atlántico, Isabel Torres 21, 39011 Santander, Spain;
- Correspondence:
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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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Colditz J, Thiele S, Baschant U, Niehrs C, Bonewald LF, Hofbauer LC, Rauner M. Postnatal Skeletal Deletion of Dickkopf-1 Increases Bone Formation and Bone Volume in Male and Female Mice, Despite Increased Sclerostin Expression. J Bone Miner Res 2018; 33:1698-1707. [PMID: 29734465 DOI: 10.1002/jbmr.3463] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/16/2018] [Revised: 04/16/2018] [Accepted: 04/28/2018] [Indexed: 12/14/2022]
Abstract
The Wnt antagonist Dickkopf-1 (Dkk1) is a negative regulator of osteoblast function and bone mass. However, because of the lack of appropriate models, many aspects of its role in the regulation of postnatal bone turnover and its cellular source have remained unknown. In this study, we deleted Dkk1 postnatally and in different cell types using various Cre-drivers (Rosa26-ERT2-Cre, Osx-cre, Dmp1-Cre) and assessed to which extent cells of the osteoblastic lineage contribute to the effects of Dkk1 on bone turnover and homeostasis. Female and male mice were examined at 12 weeks of age. Mice with a global or cell type-specific deletion of Dkk1 showed a two- to threefold higher bone volume compared with their Cre-negative littermates. The mineral apposition rate and the bone formation rate were increased two- to fourfold in all three mouse lines, despite a significant increase in systemic and skeletal levels of sclerostin. Dkk1 deletion further reduced the number of osteoclasts about twofold, which was accompanied by a strong decrease in the receptor activator of nuclear factor-κB ligand/osteoprotegerin mRNA ratio in femoral bone. Despite similar increases in bone mass, the deletion of Dkk1 in osterix-expressing cells reduced circulating Dkk1 significantly (males, -79%; females, -77%), whereas they were not changed in Dkk1fl/fl ;Dmp1-Cre mice. However, both lines showed significantly reduced Dkk1 mRNA levels in bone. In summary, we show that lack of Dkk1 in cells of the osteoblastic lineage leads to high bone mass with increased bone formation, despite increased levels of sclerostin. Moreover, the majority of systemic Dkk1 appears to originate from osteoprogenitors but not from mature osteoblasts or osteocytes. Nevertheless, the amount of Dkk1 produced locally by more mature osteogenic cells is sufficient to modulate bone mass. Thus, this study highlights the importance of local Wnt signaling on postnatal bone homeostasis. © 2018 American Society for Bone and Mineral Research.
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Affiliation(s)
- Juliane Colditz
- Department of Medicine III, Technische Universität Dresden, Dresden, Germany.,Center for Healthy Aging, Technische Universität Dresden, Dresden, Germany
| | - Sylvia Thiele
- Department of Medicine III, Technische Universität Dresden, Dresden, Germany.,Center for Healthy Aging, Technische Universität Dresden, Dresden, Germany
| | - Ulrike Baschant
- Department of Medicine III, Technische Universität Dresden, Dresden, Germany.,Center for Healthy Aging, Technische Universität Dresden, Dresden, Germany
| | - Christof Niehrs
- Division of Molecular Embryology, DKFZ-ZMBH Alliance, Heidelberg, Germany.,Institute of Molecular Biology, Mainz, Germany
| | - Lynda F Bonewald
- Indiana Center for Musculoskeletal Health, Departments of Anatomy and Cell Biology and Orthopaedic Surgery, School of Medicine, Indianapolis, IN, USA
| | - Lorenz C Hofbauer
- Department of Medicine III, Technische Universität Dresden, Dresden, Germany.,Center for Healthy Aging, Technische Universität Dresden, Dresden, Germany.,Center for Regenerative Therapies Dresden, Technische Universität Dresden, Dresden, Germany
| | - Martina Rauner
- Department of Medicine III, Technische Universität Dresden, Dresden, Germany.,Center for Healthy Aging, Technische Universität Dresden, Dresden, Germany
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Beggs LA, Ye F, Ghosh P, Beck DT, Conover CF, Balaez A, Miller JR, Phillips EG, Zheng N, Williams AA, Aguirre JI, Wronski TJ, Bose PK, Borst SE, Yarrow JF. Sclerostin inhibition prevents spinal cord injury-induced cancellous bone loss. J Bone Miner Res 2015; 30:681-9. [PMID: 25359699 PMCID: PMC8367350 DOI: 10.1002/jbmr.2396] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/11/2014] [Revised: 10/28/2014] [Accepted: 10/30/2014] [Indexed: 01/22/2023]
Abstract
Spinal cord injury (SCI) results in rapid and extensive sublesional bone loss. Sclerostin, an osteocyte-derived glycoprotein that negatively regulates intraskeletal Wnt signaling, is elevated after SCI and may represent a mechanism underlying this excessive bone loss. However, it remains unknown whether pharmacologic sclerostin inhibition ameliorates bone loss subsequent to SCI. Our primary purposes were to determine whether a sclerostin antibody (Scl-Ab) prevents hindlimb cancellous bone loss in a rodent SCI model and to compare the effects of a Scl-Ab to that of testosterone-enanthate (TE), an agent that we have previously shown prevents SCI-induced bone loss. Fifty-five (n = 11-19/group) skeletally mature male Sprague-Dawley rats were randomized to receive: (A) SHAM surgery (T8 laminectomy), (B) moderate-severe (250 kilodyne) SCI, (C) 250 kilodyne SCI + TE (7.0 mg/wk, im), or (D) 250 kilodyne SCI + Scl-Ab (25 mg/kg, twice weekly, sc) for 3 weeks. Twenty-one days post-injury, SCI animals exhibited reduced hindlimb cancellous bone volume at the proximal tibia (via μCT and histomorphometry) and distal femur (via μCT), characterized by reduced trabecular number and thickness. SCI also reduced trabecular connectivity and platelike trabecular structures, indicating diminished structural integrity of the remaining cancellous network, and produced deficits in cortical bone (femoral diaphysis) strength. Scl-Ab and TE both prevented SCI-induced cancellous bone loss, albeit via differing mechanisms. Specifically, Scl-Ab increased osteoblast surface and bone formation, indicating direct bone anabolic effects, whereas TE reduced osteoclast surface with minimal effect on bone formation, indicating antiresorptive effects. The deleterious microarchitectural alterations in the trabecular network were also prevented in SCI + Scl-Ab and SCI + TE animals, whereas only Scl-Ab completely prevented the reduction in cortical bone strength. Our findings provide the first evidence indicating that sclerostin inhibition represents a viable treatment to prevent SCI-induced cancellous and cortical bone deficits and provides preliminary rationale for future clinical trials focused on evaluating whether Scl-Ab prevents osteoporosis in the SCI population.
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Affiliation(s)
- Luke A Beggs
- Research Service, Department of Veterans Affairs Medical Center, North Florida/South Georgia Veterans Health System, Gainesville, FL, USA
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL, USA
| | - Fan Ye
- Research Service, Department of Veterans Affairs Medical Center, North Florida/South Georgia Veterans Health System, Gainesville, FL, USA
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL, USA
| | - Payal Ghosh
- Research Service, Department of Veterans Affairs Medical Center, North Florida/South Georgia Veterans Health System, Gainesville, FL, USA
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL, USA
| | - Darren T Beck
- Geriatrics Research, Education, and Clinical Center (GRECC), Department of Veterans Affairs Medical Center, North Florida/South Georgia Veterans Health System, Gainesville, FL, USA
- Department of Kinesiology, University of Rhode Island, Kingston, RI, USA
| | - Christine F Conover
- Research Service, Department of Veterans Affairs Medical Center, North Florida/South Georgia Veterans Health System, Gainesville, FL, USA
| | - Alexander Balaez
- Research Service, Department of Veterans Affairs Medical Center, North Florida/South Georgia Veterans Health System, Gainesville, FL, USA
| | - Julie R Miller
- Research Service, Department of Veterans Affairs Medical Center, North Florida/South Georgia Veterans Health System, Gainesville, FL, USA
| | - Ean G Phillips
- Research Service, Department of Veterans Affairs Medical Center, North Florida/South Georgia Veterans Health System, Gainesville, FL, USA
| | - Nigel Zheng
- Department of Mechanical Engineering and Engineering Science, University of North Carolina at Charlotte, Charlotte NC,, USA
| | - Alyssa A Williams
- Department of Physiological Sciences, University of Florida, Gainesville, FL, USA
| | - JIgnacio Aguirre
- Department of Physiological Sciences, University of Florida, Gainesville, FL, USA
| | - Thomas J Wronski
- Department of Physiological Sciences, University of Florida, Gainesville, FL, USA
| | - Prodip K Bose
- Research Service, Department of Veterans Affairs Medical Center, North Florida/South Georgia Veterans Health System, Gainesville, FL, USA
- Department of Physiological Sciences, University of Florida, Gainesville, FL, USA
- Department of Neurology, University of Florida, Gainesville, FL, USA
| | - Stephen E Borst
- Research Service, Department of Veterans Affairs Medical Center, North Florida/South Georgia Veterans Health System, Gainesville, FL, USA
- Geriatrics Research, Education, and Clinical Center (GRECC), Department of Veterans Affairs Medical Center, North Florida/South Georgia Veterans Health System, Gainesville, FL, USA
| | - Joshua F Yarrow
- Research Service, Department of Veterans Affairs Medical Center, North Florida/South Georgia Veterans Health System, Gainesville, FL, USA
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL, USA
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Chin KY, Ima-Nirwana S. The effects of orchidectomy and supraphysiological testosterone administration on trabecular bone structure and gene expression in rats. Aging Male 2015; 18:60-6. [PMID: 25166624 DOI: 10.3109/13685538.2014.954995] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
OBJECTIVE This study aimed to determine the effects of orchidectomy and supraphysiological testosterone replacement on trabecular structure and gene expression in the bone. METHODS Twenty-four 3-month old male rats were randomized into sham (SH), orchidectomized (ORX) and testosterone-treated (TE) groups. Orchidectomy was performed on the ORX and TE group. Weekly testosterone enanthate intramuscular injection at 7 mg/kg body weight was administered to the TE group for 8 weeks while the other groups received peanut oil as vehicle. Blood was collected before and after treatment for serum testosterone analysis. The femora and tibiae were harvested after the treatment period for trabecular structure and gene expression analysis. RESULTS The trabecular bone volume decreased significantly and the porosity increased significantly in the ORX group compared to the SH group (p < 0.05). Testosterone treatment prevented all these changes (p < 0.05). The expression of osteogenic genes decreased significantly in the ORX group compared to the SH group (p < 0.05). Testosterone treatment decreased the expressions of RANKL and OPG genes significantly (p < 0.05). CONCLUSION Orchidectomy-induced degeneration in trabecular structure is caused by a decrease in the expressions of osteogenic genes. Supraphysiological testosterone replacement is able to prevent these degenerative changes in the bone despite the modest changes in gene expression.
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Affiliation(s)
- Kok-Yong Chin
- Faculty of Medicine, Department of Pharmacology, Universiti Kebangsaan Malaysia , Kuala Lumpur , Malaysia
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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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Sun L, Pan J, Peng Y, Wu Y, Li J, Liu X, Qin Y, Bauman WA, Cardozo C, Zaidi M, Qin W. Anabolic steroids reduce spinal cord injury-related bone loss in rats associated with increased Wnt signaling. J Spinal Cord Med 2013; 36:616-22. [PMID: 24090150 PMCID: PMC3831322 DOI: 10.1179/2045772312y.0000000020] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
BACKGROUND Spinal cord injury (SCI) causes severe bone loss. At present, there is no practical treatment to delay or prevent bone loss in individuals with motor-complete SCI. Hypogonadism is common in men after SCI and may exacerbate bone loss. The anabolic steroid nandrolone reduces bone loss due to microgravity or nerve transection. OBJECTIVE To determine whether nandrolone reduced bone loss after SCI and, if so, to explore the mechanisms of nandrolone action. METHODS Male rats with complete transection of the spinal cord were administered nandrolone combined with a physiological replacement dose of testosterone, or vehicle, beginning on day 29 after SCI and continued for 28 days. RESULTS SCI reduced distal femoral and proximal tibial bone mineral density (BMD) by 25 and 16%, respectively, at 56 days. This bone loss was attenuated by nandrolone. In ex vivo osteoclasts cultures, SCI increased mRNA levels for tartrate-resistant acid phosphatase (TRAP) and calcitonin receptor; nandrolone-normalized expression levels of these transcripts. In ex vivo osteoblast cultures, SCI increased receptor activator of NF-kB ligand (RANKL) mRNA levels but did not alter osteoprotegerin (OPG) mRNA expression; nandrolone-increased expression of OPG and OPG/RANKL ratio. SCI reduced mRNA levels of Wnt signaling-related genes Wnt3a, low-density lipoprotein receptor-related protein 5 (LRP5), Fzd5, Tcf7, and ectodermal-neural cortex 1 (ENC1) in osteoblasts, whereas nandrolone increased expression of each of these genes. CONCLUSIONS The results demonstrate that nandrolone reduces bone loss after SCI. A potential mechanism is suggested by our findings wherein nandrolone modulates genes for differentiation and activity of osteoclasts and osteoblasts, at least in part, through the activation of Wnt signaling.
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Affiliation(s)
- Li Sun
- Mount Sinai Bone Program, Mount Sinai School of Medicine, New York, NY, USA
| | - Jiangping Pan
- Center of Excellence for the Medical Consequences of SCI, James J. Peters VA Medical Center, Bronx, NY, USA
| | - Yuanzhen Peng
- Mount Sinai Bone Program, Mount Sinai School of Medicine, New York, NY, USA
| | - Yong Wu
- Center of Excellence for the Medical Consequences of SCI, James J. Peters VA Medical Center, Bronx, NY, USA
| | - Jianghua Li
- Mount Sinai Bone Program, Mount Sinai School of Medicine, New York, NY, USA
| | - Xuan Liu
- Mount Sinai Bone Program, Mount Sinai School of Medicine, New York, NY, USA
| | - Yiwen Qin
- Center of Excellence for the Medical Consequences of SCI, James J. Peters VA Medical Center, Bronx, NY, USA
| | - William A. Bauman
- Center of Excellence for the Medical Consequences of SCI, James J. Peters VA Medical Center, Bronx, NY, USA; Department of Medicine, Mount Sinai School of Medicine, New York, NY, USA; and Department of Rehabilitation Medicine, Mount Sinai School of Medicine, New York, NY, USA
| | - Christopher Cardozo
- Center of Excellence for the Medical Consequences of SCI, James J. Peters VA Medical Center, Bronx, NY, USA; Department of Medicine, Mount Sinai School of Medicine, New York, NY, USA; and Department of Rehabilitation Medicine, Mount Sinai School of Medicine, New York, NY, USA
| | - Mone Zaidi
- Mount Sinai Bone Program, Mount Sinai School of Medicine, New York, NY, USA
| | - Weiping Qin
- Center of Excellence for the Medical Consequences of SCI, James J. Peters VA Medical Center, Bronx, NY, USA; and Department of Medicine, Mount Sinai School of Medicine, New York, NY, USA,Correspondence to: Weiping Qin, James J. Peters VA Medical Center, 130 West Kingsbridge Road, Bronx, NY 10468, USA.
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Liu XH, Wu Y, Yao S, Levine AC, Kirschenbaum A, Collier L, Bauman WA, Cardozo CP. Androgens up-regulate transcription of the Notch inhibitor Numb in C2C12 myoblasts via Wnt/β-catenin signaling to T cell factor elements in the Numb promoter. J Biol Chem 2013; 288:17990-8. [PMID: 23649620 DOI: 10.1074/jbc.m113.478487] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Androgen signaling via the androgen receptor is a key pathway that contributes to development, cell fate decisions, and differentiation, including that of myogenic progenitors. Androgens and synthetic steroids have well established anabolic actions on skeletal muscle. Wnt and Notch signaling pathways are also essential to myogenic cell fate decisions during development and tissue repair. However, the interactions among these pathways are largely unknown. Androgenic regulation of Wnt signaling has been reported. Nandrolone, an anabolic steroid, has been shown to inhibit Notch signaling and up-regulate Numb, a Notch inhibitor. To elucidate the mechanisms of interaction between nandrolone and Wnt/Notch signaling, we investigated the effects of nandrolone on Numb expression and Wnt signaling and determined the roles of Wnt signaling in nandrolone-induced Numb expression in C2C12 myoblasts. Nandrolone increased Numb mRNA and protein levels and T cell factor (Tcf) transcriptional activity via inhibition of glycogen synthase kinase 3β. Up-regulation of Numb expression by nandrolone was blocked by the Wnt inhibitors, sFRP1 and DKK1, whereas Wnt3a increased Numb mRNA and protein expression. In addition, we observed that the proximal promoter of the Numb gene had functional Tcf binding elements to which β-catenin was recruited in a manner enhanced by both nandrolone and Wnt3a. Moreover, site-directed mutagenesis indicated that the Tcf binding sites in the Numb promoter are required for the nandrolone-induced Numb transcriptional activation in this cell line. These results reveal a novel molecular mechanism underlying up-regulation of Numb transcription with a critical role for increased canonical Wnt signaling. In addition, the data identify Numb as a novel target gene of the Wnt signaling pathway by which Wnts would be able to inhibit Notch signaling.
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Affiliation(s)
- Xin-Hua Liu
- James J. Peter Veterans Affairs Medical Center, Bronx, New York 10468, USA
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11
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Sex hormones and bone health in males. Arch Biochem Biophys 2010; 503:110-7. [PMID: 20627086 DOI: 10.1016/j.abb.2010.07.001] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2010] [Revised: 06/25/2010] [Accepted: 07/01/2010] [Indexed: 11/23/2022]
Abstract
Sex steroids play a key role in maintaining skeletal integrity lifelong, through a complex variety of endocrine, but also paracrine and possibly autocrine actions. The current knowledge that androgens may act as pro-hormones for estrogens has seriously challenged many traditional views, so that, at least for their skeletal actions, these can no longer be considered exclusively "male" or "female" hormones.
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12
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Abstract
Beta-Catenin-dependent canonical Wnt signaling plays an important role in bone metabolism by controlling differentiation of bone-forming osteoblasts and bone-resorbing osteoclasts. To investigate its function in osteocytes, the cell type constituting the majority of bone cells, we generated osteocyte-specific beta-catenin-deficient mice (Ctnnb1(loxP/loxP); Dmp1-Cre). Homozygous mutants were born at normal Mendelian frequency with no obvious morphological abnormalities or detectable differences in size or body weight, but bone mass accrual was strongly impaired due to early-onset, progressive bone loss in the appendicular and axial skeleton with mild growth retardation and premature lethality. Cancellous bone mass was almost completely absent, and cortical bone thickness was dramatically reduced. The low-bone-mass phenotype was associated with increased osteoclast number and activity, whereas osteoblast function and osteocyte density were normal. Cortical bone Wnt/beta-catenin target gene expression was reduced, and of the known regulators of osteoclast differentiation, osteoprotegerin (OPG) expression was significantly downregulated in osteocyte bone fractions of mutant mice. Moreover, the OPG levels expressed by osteocytes were higher than or comparable to the levels expressed by osteoblasts during skeletal growth and at maturity, suggesting that the reduction in osteocytic OPG and the concomitant increase in osteocytic RANKL/OPG ratio contribute to the increased number of osteoclasts and resorption in osteocyte-specific beta-catenin mutants. Together, these results reveal a crucial novel function for osteocyte beta-catenin signaling in controlling bone homeostasis.
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13
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Noh T, Gabet Y, Cogan J, Shi Y, Tank A, Sasaki T, Criswell B, Dixon A, Lee C, Tam J, Kohler T, Segev E, Kockeritz L, Woodgett J, Müller R, Chai Y, Smith E, Bab I, Frenkel B. Lef1 haploinsufficient mice display a low turnover and low bone mass phenotype in a gender- and age-specific manner. PLoS One 2009; 4:e5438. [PMID: 19412553 PMCID: PMC2673053 DOI: 10.1371/journal.pone.0005438] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2008] [Accepted: 04/02/2009] [Indexed: 12/13/2022] Open
Abstract
We investigated the role of Lef1, one of the four transcription factors that transmit Wnt signaling to the genome, in the regulation of bone mass. Microcomputed tomographic analysis of 13- and 17-week-old mice revealed significantly reduced trabecular bone mass in Lef1(+/-) females compared to littermate wild-type females. This was attributable to decreased osteoblast activity and bone formation as indicated by histomorphometric analysis of bone remodeling. In contrast to females, bone mass was unaffected by Lef1 haploinsufficiency in males. Similarly, females were substantially more responsive than males to haploinsufficiency in Gsk3beta, a negative regulator of the Wnt pathway, displaying in this case a high bone mass phenotype. Lef1 haploinsufficiency also led to low bone mass in males lacking functional androgen receptor (AR) (tfm mutants). The protective skeletal effect of AR against Wnt-related low bone mass is not necessarily a result of direct interaction between the AR and Wnt signaling pathways, because Lef1(+/-) female mice had normal bone mass at the age of 34 weeks. Thus, our results indicate an age- and gender-dependent role for Lef1 in regulating bone formation and bone mass in vivo. The resistance to Lef1 haploinsufficiency in males with active AR and in old females could be due to the reduced bone turnover in these mice.
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Affiliation(s)
- Tommy Noh
- Department of Biochemistry and Molecular Biology, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
- Institute for Genetic Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
| | - Yankel Gabet
- Department of Biochemistry and Molecular Biology, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
- Institute for Genetic Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
| | - Jon Cogan
- Institute for Genetic Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
| | - Yunfan Shi
- Institute for Genetic Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
| | - Archana Tank
- Department of Biochemistry and Molecular Biology, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
- Institute for Genetic Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
| | - Tomoyo Sasaki
- Center for Craniofacial Molecular Biology, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
| | - Braden Criswell
- Institute for Genetic Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
| | - Alexis Dixon
- Institute for Genetic Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
| | - Christopher Lee
- Institute for Genetic Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
| | - Joseph Tam
- Bone Laboratory, Faculty of Dental Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Thomas Kohler
- Institute for Biomechanics, ETH Zürich, Zürich, Switzerland
| | - Eran Segev
- Bone Laboratory, Faculty of Dental Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Lisa Kockeritz
- Ontario Cancer Institute/Princess Margaret Hospital, Toronto, Ontario, Canada
| | - James Woodgett
- Ontario Cancer Institute/Princess Margaret Hospital, Toronto, Ontario, Canada
| | - Ralph Müller
- Institute for Biomechanics, ETH Zürich, Zürich, Switzerland
| | - Yang Chai
- Center for Craniofacial Molecular Biology, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
| | - Elisheva Smith
- Institute for Genetic Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
| | - Itai Bab
- Bone Laboratory, Faculty of Dental Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Baruch Frenkel
- Department of Biochemistry and Molecular Biology, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
- Institute for Genetic Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
- Department of Orthopaedic Surgery, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
- * E-mail:
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