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Abstract
PURPOSE OF REVIEW The purpose of this review is to provide a background on osteocytes and the primary cilium, discussing the role it plays in osteocyte mechanosensing. RECENT FINDINGS Osteocytes are thought to be the primary mechanosensing cells in bone tissue, regulating bone adaptation in response to exercise, with the primary cilium suggested to be a key mechanosensing mechanism in bone. More recent work has suggested that, rather than being direct mechanosensors themselves, primary cilia in bone may instead form a key chemo-signalling nexus for processing mechanoregulated signalling pathways. Recent evidence suggests that pharmacologically induced lengthening of the primary cilium in osteocytes may potentiate greater mechanotransduction, rather than greater mechanosensing. While more research is required to delineate the specific osteocyte mechanobiological molecular mechanisms governed by the primary cilium, it is clear from the literature that the primary cilium has significant potential as a therapeutic target to treat mechanoregulated bone diseases, such as osteoporosis.
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Affiliation(s)
- Stefaan W Verbruggen
- Department of Mechanical Engineering, University of Sheffield, Sheffield, UK.
- INSIGNEO Institute for in silico Medicine, University of Sheffield, Sheffield, UK.
- Centre for Predictive in vitro Models, Centre for Bioengineering, School of Engineering and Materials Science, Queen Mary University of London, London, E1 4NS, UK.
| | - Anuphan Sittichokechaiwut
- Department of Preventive Dentistry, Faculty of Dentistry, Naresuan University, Phitsanulok, Thailand
- Center of Excellence in Biomaterials, Naresuan University, Phitsanulok, Thailand
| | - Gwendolen C Reilly
- INSIGNEO Institute for in silico Medicine, University of Sheffield, Sheffield, UK
- Kroto Research Institute, Department of Materials Science and Engineering, University of Sheffield, Sheffield, UK
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2
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Desai S, Wu J, Horkeby K, Norgård M, Ohlsson C, Windahl SH, Engdahl C. A COX-2 Inhibitor Does Not Interfere With the Bone-Protective Effects of Loading in Male Mice With Arthritis. JBMR Plus 2023; 7:e10751. [PMID: 37457879 PMCID: PMC10339087 DOI: 10.1002/jbm4.10751] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Revised: 03/03/2023] [Accepted: 04/11/2023] [Indexed: 07/18/2023] Open
Abstract
Mechanical loading enhances bone strength and counteracts arthritis-induced inflammation-mediated bone loss in female mice. It is unknown whether nonsteroidal anti-inflammatory drugs (NSAIDs; eg, COX-2 inhibitors) can reduce inflammation without affecting the loading-associated bone formation in male mice. The aim of this study was to investigate if loading combined with a COX-2 inhibitor (NS-398) could prevent arthritis-induced bone loss and inflammation in male mice. Four-month-old male C57BL/6J mice were subjected to axial tibial mechanical loading three times/week for 2 weeks. Local mono-arthritis was induced with a systemic injection of methylated bovine serum albumin on the first day of loading, followed by a local injection in one knee 1 week later. The arthritis induction, knee swelling, bone architecture, and osteoclast number were evaluated in the hind limbs. C-terminal cross-links as a marker for osteoclast activity was measured in serum. Compared with loading and arthritis alone, loading of the arthritic joint enhanced swelling that was partly counteracted by NS-398. Loading of the arthritic joint enhanced synovitis and articular cartilage damage compared with loading alone. Loading increased cortical bone and counteracted the arthritis-induced decrease in epiphyseal bone. NS-398 did not alter the bone-protective effects of loading. C-terminal cross-links, a bone resorption marker, was increased by arthritis but not loading. In conclusion, loading prevented arthritis-induced epiphyseal and metaphyseal bone loss, and NS-398 reduced knee swelling without affecting the bone-protective effects of loading. If our results can be extrapolated to the human situation, specific COX-2 inhibitors could be used in combination with loading exercise to prevent pain and swelling of the joint without influencing the bone-protective effects of loading. © 2023 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.
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Affiliation(s)
- Suchita Desai
- Department of Laboratory Medicine, Division of Pathology, Karolinska InstitutetKarolinska University HospitalHuddingeSweden
| | - Jianyao Wu
- Sahlgrenska Osteoporosis Centre, Centre for Bone and Arthritis Research, Department of Internal Medicine and Clinical NutritionInstitute of Medicine, Sahlgrenska Academy, University of GothenburgGothenburgSweden
| | - Karin Horkeby
- Sahlgrenska Osteoporosis Centre, Centre for Bone and Arthritis Research, Department of Internal Medicine and Clinical NutritionInstitute of Medicine, Sahlgrenska Academy, University of GothenburgGothenburgSweden
| | - Maria Norgård
- Department of Laboratory Medicine, Division of Pathology, Karolinska InstitutetKarolinska University HospitalHuddingeSweden
| | - 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
| | - Sara H Windahl
- Department of Laboratory Medicine, Division of Pathology, Karolinska InstitutetKarolinska University HospitalHuddingeSweden
| | - Cecilia Engdahl
- Sahlgrenska Osteoporosis Centre, Centre for Bone and Arthritis Research, Department of Internal Medicine and Clinical NutritionInstitute of Medicine, Sahlgrenska Academy, University of GothenburgGothenburgSweden
- Centre for Bone and Arthritis Research, Department of Rheumatology and Inflammation ResearchInstitute of Medicine, Sahlgrenska Academy, University of GothenburgGothenburgSweden
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Steppe L, Krüger B, Tschaffon-Müller MEA, Ramge JM, Schoppa A, Ignatius A, Haffner-Luntzer M. Activation function 2 (AF2) domain of estrogen receptor-α regulates mechanotransduction during bone fracture healing in estrogen-competent mice. Bone 2023; 172:116781. [PMID: 37100360 DOI: 10.1016/j.bone.2023.116781] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Revised: 04/20/2023] [Accepted: 04/20/2023] [Indexed: 04/28/2023]
Abstract
External mechanostimulation applied by whole-body low-magnitude high-frequency vibration (LMHFV) was demonstrated to cause no or negative effects on fracture healing in estrogen-competent rodents, while in ovariectomized (OVX), estrogen-deficient rodents bone formation after fracture was improved. Using mice with an osteoblast-specific deletion of the estrogen receptor α (ERα), we demonstrated that ERα signaling in osteoblasts is required for both the anabolic and catabolic effects of LMHFV during bone fracture healing in OVX and non-OVX mice, respectively. Because the vibration effects mediated by ERα were strictly dependent on the estrogen status, we hypothesized different roles of ligand-dependent and -independent ERα signaling. To investigate this assumption in the present study, we used mice with a deletion of the C-terminal activation function (AF) domain-2 of the ERα receptor, which mediated ligand-dependent ERα signaling (ERαAF-20). OVX and non-OVX ERαAF-20 animals were subjected to femur osteotomy followed by vibration treatment. We revealed that estrogen-competent mice lacking the AF-2 domain were protected from LMHFV-induced impaired bone regeneration, while the anabolic effects of vibration in OVX mice were not affected by the AF-2 knockout. RNA sequencing further showed that genes involved in Hippo/Yap1-Taz and Wnt signaling were significantly downregulated upon LMHFV in the presence of estrogen in vitro. In conclusion, we demonstrated that the AF-2 domain is crucial for the negative effects of vibration during bone fracture healing in estrogen-competent mice suggesting that the osteoanabolic effects of vibration are rather mediated by ligand-independent ERα signaling.
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Affiliation(s)
- Lena Steppe
- Institute of Orthopedic Research and Biomechanics, University Medical Center Ulm, Helmholtzstraße 14, 89081 Ulm, Germany
| | - Benjamin Krüger
- Institute of Orthopedic Research and Biomechanics, University Medical Center Ulm, Helmholtzstraße 14, 89081 Ulm, Germany
| | | | - Jan-Moritz Ramge
- Institute of Orthopedic Research and Biomechanics, University Medical Center Ulm, Helmholtzstraße 14, 89081 Ulm, Germany
| | - Astrid Schoppa
- Institute of Orthopedic Research and Biomechanics, University Medical Center Ulm, Helmholtzstraße 14, 89081 Ulm, Germany
| | - Anita Ignatius
- Institute of Orthopedic Research and Biomechanics, University Medical Center Ulm, Helmholtzstraße 14, 89081 Ulm, Germany
| | - Melanie Haffner-Luntzer
- Institute of Orthopedic Research and Biomechanics, University Medical Center Ulm, Helmholtzstraße 14, 89081 Ulm, Germany.
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Mechanotransduction pathways in articular chondrocytes and the emerging role of estrogen receptor-α. Bone Res 2023; 11:13. [PMID: 36869045 PMCID: PMC9984452 DOI: 10.1038/s41413-023-00248-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Revised: 12/05/2022] [Accepted: 01/06/2023] [Indexed: 03/05/2023] Open
Abstract
In the synovial joint, mechanical force creates an important signal that influences chondrocyte behavior. The conversion of mechanical signals into biochemical cues relies on different elements in mechanotransduction pathways and culminates in changes in chondrocyte phenotype and extracellular matrix composition/structure. Recently, several mechanosensors, the first responders to mechanical force, have been discovered. However, we still have limited knowledge about the downstream molecules that enact alterations in the gene expression profile during mechanotransduction signaling. Recently, estrogen receptor α (ERα) has been shown to modulate the chondrocyte response to mechanical loading through a ligand-independent mechanism, in line with previous research showing that ERα exerts important mechanotransduction effects on other cell types, such as osteoblasts. In consideration of these recent discoveries, the goal of this review is to position ERα into the mechanotransduction pathways known to date. Specifically, we first summarize our most recent understanding of the mechanotransduction pathways in chondrocytes on the basis of three categories of actors, namely mechanosensors, mechanotransducers, and mechanoimpactors. Then, the specific roles played by ERα in mediating the chondrocyte response to mechanical loading are discussed, and the potential interactions of ERα with other molecules in mechanotransduction pathways are explored. Finally, we propose several future research directions that may advance our understanding of the roles played by ERα in mediating biomechanical cues under physiological and pathological conditions.
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Zhang X, Xiang S, Zhang Y, Liu S, Lei G, Hines S, Wang N, Lin H. In vitro study to identify ligand-independent function of estrogen receptor-α in suppressing DNA damage-induced chondrocyte senescence. FASEB J 2023; 37:e22746. [PMID: 36622202 PMCID: PMC10369926 DOI: 10.1096/fj.202201228r] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Revised: 11/29/2022] [Accepted: 12/19/2022] [Indexed: 01/10/2023]
Abstract
In osteoarthritis (OA), chondrocytes undergo many pathological alternations that are linked with cellular senescence. However, the exact pathways that lead to the generation of a senescence-like phenotype in OA chondrocytes are not clear. Previously, we found that loss of estrogen receptor-α (ERα) was associated with an increased senescence level in human chondrocytes. Since DNA damage is a common cause of cellular senescence, we aimed to study the relationship among ERα levels, DNA damage, and senescence in chondrocytes. We first examined the levels of ERα, representative markers of DNA damage and senescence in normal and OA cartilage harvested from male and female human donors, as well as from male mice. The influence of DNA damage on ERα levels was studied by treating human chondrocytes with doxorubicin (DOX), which is an often-used DNA-damaging agent. Next, we tested the potential of overexpressing ERα in reducing DNA damage and senescence levels. Lastly, we explored the interaction between ERα and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) pathway. Results indicated that the OA chondrocytes contained DNA damage and displayed senescence features, which were accompanied by significantly reduced ERα levels. Overexpression of ERα reduced the levels of DNA damage and senescence in DOX-treated normal chondrocytes and OA chondrocytes. Moreover, DOX-induced the activation of NF-κB pathway, which was partially reversed by overexpressing ERα. Taken together, our results demonstrated the critical role of ERα in maintaining the health of chondrocytes by inhibiting DNA damage and senescence. This study also suggests that maintaining the ERα level may represent a new avenue to prevent and treat OA.
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Affiliation(s)
- Xiurui Zhang
- Department of Orthopaedic Surgery, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA.,Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Shiqi Xiang
- Department of Orthopaedic Surgery, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Yiqian Zhang
- Department of Orthopaedic Surgery, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA.,Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Silvia Liu
- Department of Pathology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Guanghua Lei
- Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Sophie Hines
- Department of Orthopaedic Surgery, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Ning Wang
- Department of Orthopaedic Surgery, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA.,Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Hang Lin
- Department of Orthopaedic Surgery, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA.,Department of Bioengineering, University of Pittsburgh Swanson School of Engineering, Pittsburgh, Pennsylvania, USA.,McGowan Institute for Regenerative Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
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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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Northey JJ, Weaver VM. Mechanosensitive Steroid Hormone Signaling and Cell Fate. Endocrinology 2022; 163:bqac085. [PMID: 35678467 PMCID: PMC9237634 DOI: 10.1210/endocr/bqac085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Indexed: 11/19/2022]
Abstract
Mechanical forces collaborate across length scales to coordinate cell fate during development and the dynamic homeostasis of adult tissues. Similarly, steroid hormones interact with their nuclear and nonnuclear receptors to regulate diverse physiological processes necessary for the appropriate development and function of complex multicellular tissues. Aberrant steroid hormone action is associated with tumors originating in hormone-sensitive tissues and its disruption forms the basis of several therapeutic interventions. Prolonged perturbations to mechanical forces may further foster tumor initiation and the evolution of aggressive metastatic disease. Recent evidence suggests that steroid hormone and mechanical signaling intersect to direct cell fate during development and tumor progression. Potential mechanosensitive steroid hormone signaling pathways along with their molecular effectors will be discussed in this context.
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Affiliation(s)
- Jason J Northey
- Department of Surgery, University of California, San Francisco, CA 94143, USA
- Center for Bioengineering and Tissue Regeneration, University of California, San Francisco, San Francisco, CA 94143,USA
| | - Valerie M Weaver
- Department of Surgery, University of California, San Francisco, CA 94143, USA
- Center for Bioengineering and Tissue Regeneration, University of California, San Francisco, San Francisco, CA 94143,USA
- UCSF Helen Diller Comprehensive Cancer Center, University of California, San Francisco, San Francisco, CA 94143,USA
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, CA 94143,USA
- Department of Radiation Oncology, Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California, San Francisco, San Francisco, CA 94143,USA
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Zhao D, Hua R, Riquelme MA, Cheng H, Guda T, Xu H, Gu S, Jiang JX. Osteocytes regulate bone anabolic response to mechanical loading in male mice via activation of integrin α5. Bone Res 2022; 10:49. [PMID: 35851577 PMCID: PMC9293884 DOI: 10.1038/s41413-022-00222-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Revised: 05/25/2022] [Accepted: 06/13/2022] [Indexed: 12/18/2022] Open
Abstract
Physical mechanical stimulation can maintain and even increase bone mass. Here, we report an important role of osteocytic integrin α5 in regulating the anabolic response of bone to mechanical loading using an Itga5 conditional gene knockout (cKO) mouse model. Integrin α5 gene deletion increased apoptotic osteocytes and reduced cortical anabolic responses to tibial compression including decreased endosteal osteoblasts and bone formation, and increased endosteal osteoclasts and bone resorption, contributing to the decreased bone area fraction and biomechanical properties, leading to an enlarged bone marrow area in cKO mice. Similar disruption of anabolic responses to mechanical loading was also detected in cKO trabecular bone. Moreover, integrin α5 deficiency impeded load-induced Cx43 hemichannel opening, and production and release of PGE2, an anabolic factor, resulting in attenuated effects of the loading on catabolic sclerostin (SOST) reduction and anabolic β-catenin increase. Together, this study shows an indispensable role of integrin α5 in osteocytes in the anabolic action of mechanical loading on skeletal tissue through activation of hemichannels and PGE2-evoked gene expression. Integrin α5 could act as a potential new therapeutic target for bone loss, especially in the elderly population with impeded mechanical sensitivity.
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Affiliation(s)
- Dezhi Zhao
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center, San Antonio, TX, USA
- School of Life Sciences, Northwestern Polytechnical University, Xi'an, China
| | - Rui Hua
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center, San Antonio, TX, USA
| | - Manuel A Riquelme
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center, San Antonio, TX, USA
| | - Hongyun Cheng
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center, San Antonio, TX, USA
| | - Teja Guda
- Department of Biomedical Engineering and Chemical Engineering, University of Texas, San Antonio, TX, USA
| | - Huiyun Xu
- School of Life Sciences, Northwestern Polytechnical University, Xi'an, China
| | - Sumin Gu
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center, San Antonio, TX, USA
| | - Jean X Jiang
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center, San Antonio, TX, USA.
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Kim NR, David K, Sommers V, Schollaert D, Deboel L, Ohlsson C, Gustafsson JÅ, Antonio L, Decallonne B, Claessens F, Vanderschueren D, Dubois V. Inactivation of AR or ERα in Extrahypothalamic Neurons Does not Affect Osteogenic Response to Loading in Male Mice. Endocrinology 2022; 163:6594680. [PMID: 35640239 DOI: 10.1210/endocr/bqac080] [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: 12/15/2021] [Indexed: 11/19/2022]
Abstract
Failure of bone mass maintenance in spite of functional loading is an important contributor to osteoporosis and related fractures. While the link between sex steroids and the osteogenic response to loading is well established, the underlying mechanisms are unknown, hampering clinical relevance. Androgens inhibit mechanoresponsiveness in male mice, but the cell type mediating this effect remains unidentified. To evaluate the role of neuronal sex steroid receptor signaling in the male bone's adaptive capacity, we subjected adult male mice with an extrahypothalamic neuron-specific knockout of the androgen receptor (N-ARKO) or the estrogen receptor alpha (N-ERαKO) to in vivo mechanical stimulation of the tibia. Loading increased cortical thickness in the control animals mainly through periosteal expansion, as total cross-sectional tissue area and cortical bone area but not medullary area were higher in the loaded than the unloaded tibia. Trabecular bone volume fraction also increased upon loading in the control group, mostly due to trabecular thickening. N-ARKO and N-ERαKO males displayed a loading response at both the cortical and trabecular bone compartments that was not different from their control littermates. In conclusion, we show that the presence of androgen receptor or estrogen receptor alpha in extrahypothalamic neurons is dispensable for the osteogenic response to mechanical loading in male mice.
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Affiliation(s)
- Na Ri Kim
- Clinical and Experimental Endocrinology, Department of Chronic Diseases and Metabolism, KU Leuven, 3000 Leuven, Belgium
| | - Karel David
- Clinical and Experimental Endocrinology, Department of Chronic Diseases and Metabolism, KU Leuven, 3000 Leuven, Belgium
| | - Vera Sommers
- Molecular Endocrinology Laboratory, Department of Cellular and Molecular Medicine, KU Leuven, 3000 Leuven, Belgium
| | - Dieter Schollaert
- Clinical and Experimental Endocrinology, Department of Chronic Diseases and Metabolism, KU Leuven, 3000 Leuven, Belgium
| | - Ludo Deboel
- Clinical and Experimental Endocrinology, Department of Chronic Diseases and Metabolism, KU Leuven, 3000 Leuven, Belgium
| | - Claes Ohlsson
- Sahlgrenska Osteoporosis Centre, Centre for Bone and Arthritis Research, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, 413 45 Gothenburg, Sweden
| | - Jan-Åke Gustafsson
- Department of Biology and Biochemistry, Center for Nuclear Receptors and Cell Signaling, University of Houston, Houston, TX 77204-5056, USA
| | - Leen Antonio
- Clinical and Experimental Endocrinology, Department of Chronic Diseases and Metabolism, KU Leuven, 3000 Leuven, Belgium
| | - Brigitte Decallonne
- Clinical and Experimental Endocrinology, Department of Chronic Diseases and Metabolism, KU Leuven, 3000 Leuven, Belgium
| | - Frank Claessens
- Molecular Endocrinology Laboratory, Department of Cellular and Molecular Medicine, KU Leuven, 3000 Leuven, Belgium
| | - Dirk Vanderschueren
- Clinical and Experimental Endocrinology, Department of Chronic Diseases and Metabolism, KU Leuven, 3000 Leuven, Belgium
| | - Vanessa Dubois
- Clinical and Experimental Endocrinology, Department of Chronic Diseases and Metabolism, KU Leuven, 3000 Leuven, Belgium
- Basic and Translational Endocrinology, Department of Basic and Applied Medical Sciences, Ghent University, 9000 Ghent, Belgium
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Spasic M, Duffy MP, Jacobs CR. Fenoldopam Sensitizes Primary Cilia-Mediated Mechanosensing to Promote Osteogenic Intercellular Signaling and Whole Bone Adaptation. J Bone Miner Res 2022; 37:972-982. [PMID: 35230705 PMCID: PMC9098671 DOI: 10.1002/jbmr.4536] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Revised: 02/01/2022] [Accepted: 02/12/2022] [Indexed: 11/05/2022]
Abstract
Bone cells actively respond to mechanical stimuli to direct bone formation, yet there is no current treatment strategy for conditions of low bone mass and osteoporosis designed to target the inherent mechanosensitivity of bone. Our group has previously identified the primary cilium as a critical mechanosensor within bone, and that pharmacologically targeting the primary cilium with fenoldopam can enhance osteocyte mechanosensitivity. Here, we demonstrate that potentiating osteocyte mechanosensing with fenoldopam in vitro promotes pro-osteogenic paracrine signaling to osteoblasts. Conversely, impairing primary cilia formation and the function of key ciliary mechanotransduction proteins attenuates this intercellular signaling cascade. We then utilize an in vivo model of load-induced bone formation to demonstrate that fenoldopam treatment sensitizes bones of both healthy and osteoporotic mice to mechanical stimulation. Furthermore, we show minimal adverse effects of this treatment and demonstrate that prolonged treatment biases trabecular bone adaptation. This work is the first to examine the efficacy of targeting primary cilia-mediated mechanosensing to enhance bone formation in osteoporotic animals. © 2022 American Society for Bone and Mineral Research (ASBMR).
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Affiliation(s)
- Milos Spasic
- Department of Biomedical Engineering, Columbia University, New York, NY, USA
| | - Michael P Duffy
- Department of Biomedical Engineering, Columbia University, New York, NY, USA
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McGregor NE, Walker EC, Chan AS, Poulton IJ, Cho EHJ, Windahl SH, Sims NA. STAT3 Hyperactivation Due to SOCS3 Deletion in Murine Osteocytes Accentuates Responses to Exercise- and Load-Induced Bone Formation. J Bone Miner Res 2022; 37:547-558. [PMID: 34870348 DOI: 10.1002/jbmr.4484] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Revised: 11/07/2021] [Accepted: 11/27/2021] [Indexed: 12/16/2022]
Abstract
Cortical bone develops and changes in response to mechanical load, which is sensed by bone-embedded osteocytes. The bone formation response to load depends on STAT3 intracellular signals, which are upregulated after loading and are subject to negative feedback from Suppressor of Cytokine Signaling 3 (Socs3). Mice with Dmp1Cre-targeted knockout of Socs3 have elevated STAT3 signaling in osteocytes and display delayed cortical bone maturation characterized by impaired accrual of high-density lamellar bone. This study aimed to determine whether these mice exhibit an altered response to mechanical load. The approach used was to test both treadmill running and tibial compression in female Dmp1Cre.Socs3f/f mice. Treadmill running for 5 days per week from 6 to 11 weeks of age did not change cortical bone mass in control mice, but further delayed cortical bone maturation in Dmp1Cre.Socs3f/f mice; accrual of high-density bone was suppressed, and cortical thickness was less than in genetically-matched sedentary controls. When strain-matched anabolic tibial loading was tested, both control and Dmp1Cre.Socs3f/f mice exhibited a significantly greater cortical thickness and periosteal perimeter in loaded tibia compared with the contralateral non-loaded bone. At the site of greatest compressive strain, the loaded Dmp1Cre.Socs3f/f tibias showed a significantly greater response than controls, indicated by a greater increase in cortical thickness. This was due to a greater bone formation response on both periosteal and endocortical surfaces, including formation of abundant woven bone on the periosteum. This suggests a greater sensitivity to mechanical load in Dmp1Cre.Socs3f/f bone. In summary, mice with targeted SOCS3 deletion and immature cortical bone have an exaggerated response to both physiological and experimental mechanical loads. We conclude that there is an optimal level of osteocytic response to mechanical load required for cortical bone maturation and that load-induced bone formation may be increased by augmenting STAT3 signaling within osteocytes. © 2021 American Society for Bone and Mineral Research (ASBMR).
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Affiliation(s)
| | - Emma C Walker
- St. Vincent's Institute of Medical Research, Fitzroy, Australia
| | - Audrey Sm Chan
- Centre for Muscle Research, The University of Melbourne, Melbourne, Australia
| | | | - Ellie H-J Cho
- Biological Optical Microscopy Platform, The University of Melbourne, Melbourne, Australia
| | - Sara H Windahl
- Department of Laboratory Medicine, Division of Pathology, Karolinska Institutet, Huddinge, Sweden
| | - Natalie A Sims
- St. Vincent's Institute of Medical Research, Fitzroy, Australia.,Department of Medicine at St. Vincent's Hospital, The University of Melbourne, Fitzroy, Australia
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12
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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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13
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Steppe L, Krüger BT, Tschaffon MEA, Fischer V, Tuckermann J, Ignatius A, Haffner-Luntzer M. Estrogen Receptor α Signaling in Osteoblasts is Required for Mechanotransduction in Bone Fracture Healing. Front Bioeng Biotechnol 2021; 9:782355. [PMID: 34950644 PMCID: PMC8689144 DOI: 10.3389/fbioe.2021.782355] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Accepted: 11/24/2021] [Indexed: 12/15/2022] Open
Abstract
Biomechanical stimulation by whole-body low-magnitude high-frequency vibration (LMHFV) has demonstrated to provoke anabolic effects on bone metabolism in both non-osteoporotic and osteoporotic animals and humans. However, preclinical studies reported that vibration improved fracture healing and bone formation in osteoporotic, ovariectomized (OVX) mice representing an estrogen-deficient hormonal status, but impaired bone regeneration in skeletally healthy non-OVX mice. These effects were abolished in general estrogen receptor α (ERα)-knockout (KO) mice. However, it remains to be elucidated which cell types in the fracture callus are targeted by LMHFV during bone healing. To answer this question, we generated osteoblast lineage-specific ERα-KO mice that were subjected to ovariectomy, femur osteotomy and subsequent vibration. We found that the ERα specifically on osteoblastic lineage cells facilitated the vibration-induced effects on fracture healing, because in osteoblast lineage-specific ERα-KO (ERαfl/fl; Runx2Cre) mice the negative effects in non-OVX mice were abolished, whereas the positive effects of vibration in OVX mice were reversed. To gain greater mechanistic insights, the influence of vibration on murine and human osteogenic cells was investigated in vitro by whole genome array analysis and qPCR. The results suggested that particularly canonical WNT and Cox2/PGE2 signaling is involved in the mechanotransduction of LMHFV under estrogen-deficient conditions. In conclusion, our study demonstrates a critical role of the osteoblast lineage-specific ERα in LMHFV-induced effects on fracture healing and provides further insights into the molecular mechanism behind these effects.
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Affiliation(s)
- Lena Steppe
- Institute of Orthopedic Research and Biomechanics, University Medical Center Ulm, Ulm, Germany
| | - Benjamin Thilo Krüger
- Institute of Orthopedic Research and Biomechanics, University Medical Center Ulm, Ulm, Germany
| | | | - Verena Fischer
- Institute of Orthopedic Research and Biomechanics, University Medical Center Ulm, Ulm, Germany
| | - Jan Tuckermann
- Institute of Comparative Molecular Endocrinology (CME), Ulm University, Ulm, Germany
| | - Anita Ignatius
- Institute of Orthopedic Research and Biomechanics, University Medical Center Ulm, Ulm, Germany
| | - Melanie Haffner-Luntzer
- Institute of Orthopedic Research and Biomechanics, University Medical Center Ulm, Ulm, Germany
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14
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Lewis KJ, Cabahug-Zuckerman P, Boorman-Padgett JF, Basta-Pljakic J, Louie J, Stephen S, Spray DC, Thi MM, Seref-Ferlengez Z, Majeska RJ, Weinbaum S, Schaffler MB. Estrogen depletion on In vivo osteocyte calcium signaling responses to mechanical loading. Bone 2021; 152:116072. [PMID: 34171514 PMCID: PMC8316427 DOI: 10.1016/j.bone.2021.116072] [Citation(s) in RCA: 6] [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: 02/19/2021] [Revised: 06/15/2021] [Accepted: 06/20/2021] [Indexed: 11/27/2022]
Abstract
Microstructural adaptation of bone in response to mechanical stimuli is diminished with estrogen deprivation. Here we tested in vivo whether ovariectomy (OVX) alters the acute response of osteocytes, the principal mechanosensory cells of bone, to mechanical loading in mice. We also used super resolution microscopy (Structured Illumination microscopy or SIM) in conjunction with immunohistochemistry to assess changes in the number and organization of "osteocyte mechanosomes" - complexes of Panx1 channels, P2X7 receptors and CaV3 voltage-gated Ca2+ channels clustered around αvβ3 integrin foci on osteocyte processes. Third metatarsals bones of mice expressing an osteocyte-targeted genetically encoded Ca2+ indicator (DMP1-GCaMP3) were cyclically loaded in vivo to strains from 250 to 3000 με and osteocyte intracellular Ca2+ signaling responses were assessed in mid-diaphyses using multiphoton microscopy. The number of Ca2+ signaling osteocytes in control mice increase monotonically with applied strain magnitude for the physiological range of strains. The relationship between the number of Ca2+ signaling osteocytes and loading was unchanged at 2 days post-OVX. However, it was altered markedly at 28 days post-OVX. At loads up to 1000 με, there was a dramatic reduction in number of responding (i.e. Ca2+ signaling) osteocytes; however, at higher strains the numbers of Ca2+ signaling osteocytes were similar to control mice. OVX significantly altered the abundance, make-up and organization of osteocyte mechanosome complexes on dendritic processes. Numbers of αvβ3 foci also staining with either Panx 1, P2X7R or CaV3 declined by nearly half after OVX, pointing to a loss of osteocyte mechanosomes on the dendritic processes with estrogen depletion. At the same time, the areas of the remaining foci that stained for αvβ3 and channel proteins increased significantly, a redistribution of mechanosome components suggesting a potential compensatory response. These results demonstrate that the deleterious effects of estrogen depletion on skeletal mechanical adaptation appear at the level of mechanosensation; osteocytes lose the ability to sense small (physiological) mechanical stimuli. This decline may result at least partly from changes in the structure and organization of osteocyte mechanosomes, which contribute to the distinctive sensitivity of osteocytes (particularly their dendritic processes) to mechanical stimulation.
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Affiliation(s)
- Karl J Lewis
- Department of Biomedical Engineering, The City College of New York, New York, NY, United States of America
| | - Pamela Cabahug-Zuckerman
- Department of Biomedical Engineering, The City College of New York, New York, NY, United States of America
| | - James F Boorman-Padgett
- Department of Biomedical Engineering, The City College of New York, New York, NY, United States of America
| | - Jelena Basta-Pljakic
- Department of Biomedical Engineering, The City College of New York, New York, NY, United States of America
| | - Joyce Louie
- Department of Biomedical Engineering, The City College of New York, New York, NY, United States of America
| | - Samuel Stephen
- Department of Biomedical Engineering, The City College of New York, New York, NY, United States of America
| | - David C Spray
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY, United States of America
| | - Mia M Thi
- Orthopaedic Surgery, Albert Einstein College of Medicine, Bronx, NY, United States of America; Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY, United States of America
| | - Zeynep Seref-Ferlengez
- Orthopaedic Surgery, Albert Einstein College of Medicine, Bronx, NY, United States of America
| | - Robert J Majeska
- Department of Biomedical Engineering, The City College of New York, New York, NY, United States of America
| | - Sheldon Weinbaum
- Department of Biomedical Engineering, The City College of New York, New York, NY, United States of America
| | - Mitchell B Schaffler
- Department of Biomedical Engineering, The City College of New York, New York, NY, United States of America.
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15
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Wang JY, Chen CM, Chen CF, Wu PK, Chen WM. Suppression of Estrogen Receptor Alpha Inhibits Cell Proliferation, Differentiation and Enhances the Chemosensitivity of P53-Positive U2OS Osteosarcoma Cell. Int J Mol Sci 2021; 22:ijms222011238. [PMID: 34681897 PMCID: PMC8540067 DOI: 10.3390/ijms222011238] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 09/24/2021] [Accepted: 10/15/2021] [Indexed: 11/26/2022] Open
Abstract
Osteosarcoma is a highly malignant musculoskeletal tumor that is commonly noticed in adolescent children, young children, and elderly adults. Due to advances in surgery, chemotherapy and imaging technology, survival rates have improved to 70–80%, but chemical treatments do not enhance patient survival; in addition, the survival rate after chemical treatments is still low. The most obvious clinical feature of osteosarcoma is new bone formation, which is called “sun burst”. Estrogen receptor alpha (ERα) is an essential feature of osteogenesis and regulates cell growth in various tumors, including osteosarcoma. In this study, we sought to investigate the role of ERα in osteosarcoma and to determine if ERα can be used as a target to facilitate the chemosensitivity of osteosarcoma to current treatments. The growth rate of each cell clone was assayed by MTT and trypan blue cell counting, and cell cycle analysis was conducted by flow cytometry. Osteogenic differentiation was induced by osteogenic induction medium and quantified by ARS staining. The effects of ERα on the chemoresponse of OS cells treated with doxorubicin were evaluated by colony formation assay. Mechanistic studies were conducted by examining the levels of proteins by Western blot. The role of ERα on OS prognosis was investigated by an immunohistochemical analysis of OS tissue array. The results showed an impaired growth rate and a decreased osteogenesis ability in the ERα-silenced P53(+) OS cell line U2OS, but not in P53(−) SAOS2 cells, compared with the parental cell line. Cotreatment with tamoxifen, an estrogen receptor inhibitor, increased the sensitivity to doxorubicin, which decreased the colony formation of P53(+) U2OS cells. Cell cycle arrest in the S phase was observed in P53(+) U2OS cells cotreated with low doses of doxorubicin and tamoxifen, while increased levels of apoptosis factors indicated cell death. Moreover, patients with ER−/P53(+) U2OS showed better chemoresponse rates (necrosis rate > 90%) and impaired tumor sizes, which were compatible with the findings of basic research. Taken together, ERα may be a potential target of the current treatments for osteosarcoma that can control tumor growth and improve chemosensitivity. In addition, the expression of ERα in osteosarcoma can be a prognostic factor to predict the response to chemotherapy.
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Affiliation(s)
- Jir-You Wang
- Department of Orthopaedics, Taipei Veterans General Hospital, Taipei City 112, Taiwan; (J.-Y.W.); (C.-M.C.); (C.-F.C.); (W.-M.C.)
- Department of Orthopaedics, Therapeutical and Research Center of Musculoskeletal Tumor, Taipei Veterans General Hospital, Taipei City 112, Taiwan
- Institute of Traditional Medicine, School of Medicine, National Yang Ming Chiao Tung University, Taipei 112, Taiwan
| | - Chao-Ming Chen
- Department of Orthopaedics, Taipei Veterans General Hospital, Taipei City 112, Taiwan; (J.-Y.W.); (C.-M.C.); (C.-F.C.); (W.-M.C.)
- Department of Orthopaedics, Therapeutical and Research Center of Musculoskeletal Tumor, Taipei Veterans General Hospital, Taipei City 112, Taiwan
- Institute of Clinical Medicine, School of Medicine, National Yang Ming Chiao Tung University, Taipei 112, Taiwan
| | - Cheng-Fong Chen
- Department of Orthopaedics, Taipei Veterans General Hospital, Taipei City 112, Taiwan; (J.-Y.W.); (C.-M.C.); (C.-F.C.); (W.-M.C.)
- Department of Orthopaedics, Therapeutical and Research Center of Musculoskeletal Tumor, Taipei Veterans General Hospital, Taipei City 112, Taiwan
| | - Po-Kuei Wu
- Department of Orthopaedics, Taipei Veterans General Hospital, Taipei City 112, Taiwan; (J.-Y.W.); (C.-M.C.); (C.-F.C.); (W.-M.C.)
- Department of Orthopaedics, Therapeutical and Research Center of Musculoskeletal Tumor, Taipei Veterans General Hospital, Taipei City 112, Taiwan
- School of Medicine, National Yang Ming Chiao Tung University, Taipei 112, Taiwan
- Correspondence:
| | - Wei-Ming Chen
- Department of Orthopaedics, Taipei Veterans General Hospital, Taipei City 112, Taiwan; (J.-Y.W.); (C.-M.C.); (C.-F.C.); (W.-M.C.)
- Department of Orthopaedics, Therapeutical and Research Center of Musculoskeletal Tumor, Taipei Veterans General Hospital, Taipei City 112, Taiwan
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16
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Jackson E, Lara-Castillo N, Akhter MP, Dallas M, Scott JM, Ganesh T, Johnson ML. Osteocyte Wnt/β-catenin pathway activation upon mechanical loading is altered in ovariectomized mice. Bone Rep 2021; 15:101129. [PMID: 34584905 PMCID: PMC8455641 DOI: 10.1016/j.bonr.2021.101129] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/21/2021] [Accepted: 09/09/2021] [Indexed: 11/23/2022] Open
Abstract
Estrogen levels decline in both sexes with age, but more dramatically in females. Activation of the Wnt/β-catenin signaling pathway is central to the regulation of bone mass accrual and maintenance and in response to mechanical loading. Using the ovariectomized mouse model we examined the effect of estrogen loss on the osteocyte's ability to activate the Wnt/β-catenin pathway following mechanical loading. Female TOPGAL mice underwent ovariectomy (OVX) (n = 10) or sham surgery (n = 10) at 16 weeks of age. Four weeks post-surgery, a single loading session (global strain of 2200 με for 100 cycles at 2 Hz) was performed on the right forearm with the left as a non-loaded control. Mice (n = 5) were sacrificed at 1 or 24 hr post-load. Ulnae were stained for β-catenin activation, femurs were used for μCT and 3-pt bending/biomechanical testing, and tibiae were used for histology analysis and to determine osteocyte lacunar size using SEM and high resolution micro-XCT. A 2.2-fold increase in β-catenin signaling activation was observed 24 hr post-load in the Sham group but did not occur in the OVX group. The OVX group versus control had significant losses (p < 0.05) in trabecular BMD (−8%), BV/TV (−35%) and thickness (−23%), along with cortical thickness (−6%) and periosteal perimeter (−4%). The OVX group had significantly higher trabecular bone osteoclast numbers (63%), OCS/BS (77%) and N.OC/BPm (94%) and a significant decrease in osteoblast number (53%), OBS/BS (37%) and N.OB/BPm (40%) compared to the sham group (p < 0.05). Cortical bone lacunar number/lacunar volume and bone biomechanical properties did not change between groups. Given that the ulna is a cortical bone loading model and the lack of changes in osteocyte lacunar number/volume in cortical bone, which would alter strains experienced by osteocytes, these data suggest the absence of estrogen resulted in intrinsic changes in the ability of the osteocyte to respond to mechanical load, rather than changes in the biomechanical and architectural properties of bone. In vivo mechanical loading activates β-catenin signaling in osteocytes. Ovariectomy induced estrogen loss attenuates in vivo loading induced β-catenin signaling in osteocytes. Changes in bone material and architectural properties do not appear to explain attenuated pathway activation. Our data suggests estrogen loss alters the intrinsic ability of the osteocyte to respond to mechanical load.
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Affiliation(s)
- Erica Jackson
- UMKC, School of Dentistry, Kansas City, MO 64108, United States of America
| | | | - Mohammed P. Akhter
- Creighton University, Osteoporosis Research Center, Omaha, NE 68122, United States of America
| | - Mark Dallas
- UMKC, School of Dentistry, Kansas City, MO 64108, United States of America
| | - JoAnna M. Scott
- UMKC, School of Dentistry, Kansas City, MO 64108, United States of America
| | - Thiagarajan Ganesh
- UMKC, School of Computing and Engineering, Kansas City, MO 64110, United States of America
| | - Mark L. Johnson
- UMKC, School of Dentistry, Kansas City, MO 64108, United States of America
- Corresponding author.
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Effects of Extracellular Osteoanabolic Agents on the Endogenous Response of Osteoblastic Cells. Cells 2021; 10:cells10092383. [PMID: 34572032 PMCID: PMC8471159 DOI: 10.3390/cells10092383] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Revised: 08/31/2021] [Accepted: 09/07/2021] [Indexed: 12/27/2022] Open
Abstract
The complex multidimensional skeletal organization can adapt its structure in accordance with external contexts, demonstrating excellent self-renewal capacity. Thus, optimal extracellular environmental properties are critical for bone regeneration and inextricably linked to the mechanical and biological states of bone. It is interesting to note that the microstructure of bone depends not only on genetic determinants (which control the bone remodeling loop through autocrine and paracrine signals) but also, more importantly, on the continuous response of cells to external mechanical cues. In particular, bone cells sense mechanical signals such as shear, tensile, loading and vibration, and once activated, they react by regulating bone anabolism. Although several specific surrounding conditions needed for osteoblast cells to specifically augment bone formation have been empirically discovered, most of the underlying biomechanical cellular processes underneath remain largely unknown. Nevertheless, exogenous stimuli of endogenous osteogenesis can be applied to promote the mineral apposition rate, bone formation, bone mass and bone strength, as well as expediting fracture repair and bone regeneration. The following review summarizes the latest studies related to the proliferation and differentiation of osteoblastic cells, enhanced by mechanical forces or supplemental signaling factors (such as trace metals, nutraceuticals, vitamins and exosomes), providing a thorough overview of the exogenous osteogenic agents which can be exploited to modulate and influence the mechanically induced anabolism of bone. Furthermore, this review aims to discuss the emerging role of extracellular stimuli in skeletal metabolism as well as their potential roles and provide new perspectives for the treatment of bone disorders.
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18
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Voluntary Wheel Running Partially Compensates for the Effects of Global Estrogen Receptor-α Knockout on Cortical Bone in Young Male Mice. Int J Mol Sci 2021; 22:ijms22041734. [PMID: 33572215 PMCID: PMC7915374 DOI: 10.3390/ijms22041734] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Revised: 02/03/2021] [Accepted: 02/05/2021] [Indexed: 01/09/2023] Open
Abstract
Estrogen receptor-α knockout (ERKO) in female, but not male, mice results in an impaired osteogenic response to exercise, but the mechanisms behind this ability in males are unknown. We explored the main and interactive effects of ERKO and exercise on cortical geometry, trabecular microarchitecture, biomechanical strength, and sclerostin expression in male mice. At 12 weeks of age, male C57BL/6J ERKO and WT animals were randomized into two groups: exercise treatment (EX) and sedentary (SED) controls, until 22 weeks of age. Cortical geometry and trabecular microarchitecture were measured via μCT; biomechanical strength was assessed via three-point bending; sclerostin expression was measured via immunohistochemistry. Two-way ANOVA was used to assess sclerostin expression and trabecular microarchitecture; two-way ANCOVA with body weight was used to assess cortical geometry and biomechanical strength. ERKO positively impacted trabecular microarchitecture, and exercise had little effect on these outcomes. ERKO significantly impaired cortical geometry, but exercise was able to partially reverse these negative alterations. EX increased cortical thickness regardless of genotype. There were no effects of genotype or exercise on sclerostin expression. In conclusion, male ERKO mice retain the ability to build bone in response to exercise, but altering sclerostin expression is not one of the mechanisms involved.
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Noirrit-Esclassan E, Valera MC, Tremollieres F, Arnal JF, Lenfant F, Fontaine C, Vinel A. Critical Role of Estrogens on Bone Homeostasis in Both Male and Female: From Physiology to Medical Implications. Int J Mol Sci 2021; 22:ijms22041568. [PMID: 33557249 PMCID: PMC7913980 DOI: 10.3390/ijms22041568] [Citation(s) in RCA: 57] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 01/29/2021] [Accepted: 02/01/2021] [Indexed: 02/07/2023] Open
Abstract
Bone is a multi-skilled tissue, protecting major organs, regulating calcium phosphate balance and producing hormones. Its development during childhood determines height and stature as well as resistance against fracture in advanced age. Estrogens are key regulators of bone turnover in both females and males. These hormones play a major role in longitudinal and width growth throughout puberty as well as in the regulation of bone turnover. In women, estrogen deficiency is one of the major causes of postmenopausal osteoporosis. In this review, we will summarize the main clinical and experimental studies reporting the effects of estrogens not only in females but also in males, during different life stages. Effects of estrogens on bone involve either Estrogen Receptor (ER)α or ERβ depending on the type of bone (femur, vertebrae, tibia, mandible), the compartment (trabecular or cortical), cell types involved (osteoclasts, osteoblasts and osteocytes) and sex. Finally, we will discuss new ongoing strategies to increase the benefit/risk ratio of the hormonal treatment of menopause.
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Affiliation(s)
- Emmanuelle Noirrit-Esclassan
- I2MC, INSERM UMR 1297, University of Toulouse III, F-31000 Toulouse, France; (E.N.-E.); (M.-C.V.); (F.T.); (J.-F.A.); (F.L.); (C.F.)
- Department of Pediatric Dentistry, Faculty of Dental Surgery, University of Toulouse III, F-31000 Toulouse, France
| | - Marie-Cécile Valera
- I2MC, INSERM UMR 1297, University of Toulouse III, F-31000 Toulouse, France; (E.N.-E.); (M.-C.V.); (F.T.); (J.-F.A.); (F.L.); (C.F.)
- Department of Pediatric Dentistry, Faculty of Dental Surgery, University of Toulouse III, F-31000 Toulouse, France
| | - Florence Tremollieres
- I2MC, INSERM UMR 1297, University of Toulouse III, F-31000 Toulouse, France; (E.N.-E.); (M.-C.V.); (F.T.); (J.-F.A.); (F.L.); (C.F.)
- Menopause and Metabolic Bone Disease Center, Hôpital Paule de Viguier, University Hospital of Toulouse, F-31000 Toulouse, France
| | - Jean-Francois Arnal
- I2MC, INSERM UMR 1297, University of Toulouse III, F-31000 Toulouse, France; (E.N.-E.); (M.-C.V.); (F.T.); (J.-F.A.); (F.L.); (C.F.)
| | - Françoise Lenfant
- I2MC, INSERM UMR 1297, University of Toulouse III, F-31000 Toulouse, France; (E.N.-E.); (M.-C.V.); (F.T.); (J.-F.A.); (F.L.); (C.F.)
| | - Coralie Fontaine
- I2MC, INSERM UMR 1297, University of Toulouse III, F-31000 Toulouse, France; (E.N.-E.); (M.-C.V.); (F.T.); (J.-F.A.); (F.L.); (C.F.)
| | - Alexia Vinel
- I2MC, INSERM UMR 1297, University of Toulouse III, F-31000 Toulouse, France; (E.N.-E.); (M.-C.V.); (F.T.); (J.-F.A.); (F.L.); (C.F.)
- Department of Periodontology, Faculty of Dental Surgery, University of Toulouse III, F-31000 Toulouse, France
- Correspondence: ; Tel.: +33-5-61-77-36-10
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20
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Zhou L, Poon CCW, Wong KY, Cao S, Dong X, Zhang Y, Wong MS. Icariin ameliorates estrogen-deficiency induced bone loss by enhancing IGF-I signaling via its crosstalk with non-genomic ERα signaling. PHYTOMEDICINE : INTERNATIONAL JOURNAL OF PHYTOTHERAPY AND PHYTOPHARMACOLOGY 2021; 82:153413. [PMID: 33339654 DOI: 10.1016/j.phymed.2020.153413] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Revised: 10/20/2020] [Accepted: 11/09/2020] [Indexed: 06/12/2023]
Abstract
BACKGROUND Rapid, non-genomic estrogen receptor (ER) signaling plays an integral role in mediating the tissue selective properties of ER modulators. Icariin, a bone bioactive flavonoid, has been reported to selectively activate non-genomic ERα signaling in in vitro and in vivo studies. PURPOSE The mechanisms underlying the estrogen-like bone protective effects of icariin are not fully understood, especially those that are related to insulin-like growth factor I (IGF-1) signaling. The bone protective effects of icariin were investigated in female mature ovariectomized (OVX) rats and the signaling of IGF-IR- ERα cross-talk was determined in osteoblastic cells. STUDY DESIGN AND METHODS Icariin at 3 different dosages (50, 500 and 3000 ppm) were orally administrated to rats for 3 months through daily intake of phytoestrogen-free animal diets containing icariin. Bone marrow stromal cells (BMSCs) and osteoclast precursors from femurs were harvested for experiments and RNA-sequencing. The interactions between IGF-IR and non-genomic ERα signaling were examined in pre-osteoblastic MC3T3-E1 cells and mature osteoblasts differentiated from BMSCs. RESULTS Our results show that chronic administration of icariin to OVX rats significantly protected them against bone loss at the long bone and lumbar spine without inducing any uterotrophic effects. Ex vivo studies using BMSCs and osteoclast precursors confirmed the stimulatory effects of icariin on osteoblastogenesis and its inhibitory effects on osteoclastogenesis, respectively. RNA-sequencing analysis of mRNA from BMSCs revealed that icariin at 500 ppm significantly altered IGF-1 signaling as well as PI3K-Akt pathways. Our results demonstrated for the first time the rapid induction of interactions between IGF-IR and ERα as well as IGF-IR signaling and the downstream Akt phosphorylation by icariin in MC3T3-E1 cells. The activation of ERα and Akt phosphorylation by icariin in MC3T3-E1 cells and the osteogenic effects of icariin on ALP activity in mature osteoblasts were shown to be IGF-IR-dependent. CONCLUSION Our findings reveal that icariin activates both ERα and Akt via enhancing rapid induction of IGF-1 signaling in osteoblastic cells for osteogenesis and might be regarded as a novel pathway-selective phytoestrogen for management of postmenopausal osteoporosis.
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Affiliation(s)
- Liping Zhou
- Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong SAR
| | - Christina Chui-Wa Poon
- Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong SAR
| | - Ka-Ying Wong
- Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong SAR
| | - Sisi Cao
- Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong SAR
| | - Xiaoli Dong
- Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong SAR
| | - Yan Zhang
- Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong SAR; Longhua Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, PR China.
| | - Man-Sau Wong
- Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong SAR; State Key Laboratory of Chinese Medicine and Molecular Pharmacology (Incubation), The Hong Kong Polytechnic University Shenzhen Research Institute, Shenzhen, PR China.
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21
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Nepal AK, van Essen HW, van der Veen AJ, van Wieringen WN, Stavenuiter AWD, Cayami FK, Pals G, Micha D, Vanderschueren D, Lips P, Bravenboer N. Mechanical stress regulates bone regulatory gene expression independent of estrogen and vitamin D deficiency in rats. J Orthop Res 2021; 39:42-52. [PMID: 32530517 PMCID: PMC7818391 DOI: 10.1002/jor.24775] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/02/2019] [Revised: 05/13/2020] [Accepted: 05/25/2020] [Indexed: 02/04/2023]
Abstract
Mechanical stress determines bone mass and structure. It is not known whether mechanical loading affects expression of bone regulatory genes in a combined deficiency of estrogen and vitamin D. We studied the effect of mechanical loading on the messenger RNA (mRNA) expression of bone regulatory genes during vitamin D and/or estrogen deficiency. We performed a single bout in vivo axial loading with 14 N peak load, 2 Hz frequency and 360 cycles in right ulnae of nineteen weeks old female control Wistar rats with or without ovariectomy (OVX), vitamin D deficiency and the combination of OVX and vitamin D deficiency (N = 10/group). Total bone RNA was isolated 6 hours after loading, and mRNA expression was detected of Mepe, Fgf23, Dmp1, Phex, Sost, Col1a1, Cyp27b1, Vdr, and Esr1. Serum levels of 25(OH)D, 1,25(OH)2 D and estradiol were also measured at this time point. The effect of loading, vitamin D and estrogen deficiency and their interaction on bone gene expression was tested using a mixed effect model analysis. Mechanical loading significantly increased the mRNA expression of Mepe, and Sost, whereas it decreased the mRNA expression of Fgf23 and Esr1. Mechanical loading showed a significant interaction with vitamin D deficiency with regard to mRNA expression of Vdr and Esr1. Mechanical loading affected gene expression of Mepe, Fgf23, Sost, and Esr1 independently of vitamin D or estrogen, indicating that mechanical loading may affect bone turnover even during vitamin D deficiency and after menopause.
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Affiliation(s)
- Ashwini Kumar Nepal
- Department of Clinical Chemistry, Amsterdam UMCVrije Universiteit Amsterdam, Amsterdam Movement SciencesAmsterdamThe Netherlands
| | - Huib W. van Essen
- Department of Clinical Chemistry, Amsterdam UMCVrije Universiteit Amsterdam, Amsterdam Movement SciencesAmsterdamThe Netherlands
| | - Albert J. van der Veen
- Department of Physics and Medical Technology, Amsterdam UMCVrije Universiteit AmsterdamAmsterdamThe Netherlands
| | - Wessel N. van Wieringen
- Department of Epidemiology and Biostatistics, Amsterdam UMCVrije Universiteit AmsterdamAmsterdamThe Netherlands
- Department of MathematicsVrije Universiteit AmsterdamAmsterdamThe Netherlands
| | - Andrea W. D. Stavenuiter
- Department of Molecular Cell Biology and Immunology, Amsterdam UMCVrije Universiteit AmsterdamAmsterdamThe Netherlands
| | - Ferdy Kurniawan Cayami
- Department of Clinical Genetics, Amsterdam UMCVrije Universiteit AmsterdamAmsterdamThe Netherlands
- Department of Anatomy, Center for Biomedical Research, Faculty of MedicineDiponegoro UniversitySemarangIndonesia
| | - Gerard Pals
- Department of Clinical Genetics, Amsterdam UMCVrije Universiteit AmsterdamAmsterdamThe Netherlands
| | - Dimitra Micha
- Department of Clinical Genetics, Amsterdam UMCVrije Universiteit AmsterdamAmsterdamThe Netherlands
| | - Dirk Vanderschueren
- Laboratory of Clinical and Experimental Endocrinology, Department of Chronic Diseases, Metabolism, and AgeingKU LeuvenLeuvenBelgium
| | - Paul Lips
- Endocrine Section, Department of Internal Medicine, Amsterdam UMCVrije Universiteit Amsterdam, Amsterdam Movement SciencesAmsterdamThe Netherlands
| | - Nathalie Bravenboer
- Department of Clinical Chemistry, Amsterdam UMCVrije Universiteit Amsterdam, Amsterdam Movement SciencesAmsterdamThe Netherlands
- Endocrine Section, Department of Internal Medicine, Amsterdam UMCVrije Universiteit Amsterdam, Amsterdam Movement SciencesAmsterdamThe Netherlands
- Division Endocrinology, Department of Internal Medicine, Center of Bone QualityLeiden University Medical CenterLeidenThe Netherlands
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22
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Effects of Estrogen Receptor and Wnt Signaling Activation on Mechanically Induced Bone Formation in a Mouse Model of Postmenopausal Bone Loss. Int J Mol Sci 2020; 21:ijms21218301. [PMID: 33167497 PMCID: PMC7663944 DOI: 10.3390/ijms21218301] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Revised: 10/30/2020] [Accepted: 10/31/2020] [Indexed: 12/15/2022] Open
Abstract
In the adult skeleton, bone remodeling is required to replace damaged bone and functionally adapt bone mass and structure according to the mechanical requirements. It is regulated by multiple endocrine and paracrine factors, including hormones and growth factors, which interact in a coordinated manner. Because the response of bone to mechanical signals is dependent on functional estrogen receptor (ER) and Wnt/β-catenin signaling and is impaired in postmenopausal osteoporosis by estrogen deficiency, it is of paramount importance to elucidate the underlying mechanisms as a basis for the development of new strategies in the treatment of osteoporosis. The present study aimed to investigate the effectiveness of the activation of the ligand-dependent ER and the Wnt/β-catenin signal transduction pathways on mechanically induced bone formation using ovariectomized mice as a model of postmenopausal bone loss. We demonstrated that both pathways interact in the regulation of bone mass adaption in response to mechanical loading and that the activation of Wnt/β-catenin signaling considerably increased mechanically induced bone formation, whereas the effects of estrogen treatment strictly depended on the estrogen status in the mice.
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23
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Chuang SC, Chen CH, Chou YS, Ho ML, Chang JK. G Protein-Coupled Estrogen Receptor Mediates Cell Proliferation through the cAMP/PKA/CREB Pathway in Murine Bone Marrow Mesenchymal Stem Cells. Int J Mol Sci 2020; 21:ijms21186490. [PMID: 32899453 PMCID: PMC7555423 DOI: 10.3390/ijms21186490] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Revised: 08/31/2020] [Accepted: 09/03/2020] [Indexed: 01/12/2023] Open
Abstract
Estrogen is an important hormone to regulate skeletal physiology via estrogen receptors. The traditional estrogen receptors are ascribed to two nuclear estrogen receptors (ERs), ERα and ERβ. Moreover, G protein-coupled estrogen receptor-1 (GPER-1) was reported as a membrane receptor for estrogen in recent years. However, whether GPER-1 regulated osteogenic cell biology on skeletal system is still unclear. GPER-1 is expressed in growth plate abundantly before puberty but decreased abruptly since the very late stage of puberty in humans. It indicates GPER-1 might play an important role in skeletal growth regulation. GPER-1 expression has been confirmed in osteoblasts, osteocytes and chondrocytes, but its expression in mesenchymal stem cells (MSCs) has not been confirmed. In this study, we hypothesized that GPER-1 is expressed in bone MSCs (BMSC) and enhances BMSC proliferation. The cultured tibiae of neonatal rat and murine BMSCs were tested in our study. GPER-1-specific agonist (G-1) and antagonist (G-15), and GPER-1 siRNA (siGPER-1) were used to evaluate the downstream signaling pathway and cell proliferation. Our results revealed BrdU-positive cell counts were higher in cultured tibiae in the G-1 group. The G-1 also enhanced the cell viability and proliferation, whereas G-15 and siGPER-1 reduced these activities. The cAMP and phosphorylation of CREB were enhanced by G-1 but inhibited by G-15. We further demonstrated that GPER-1 mediates BMSC proliferation via the cAMP/PKA/p-CREB pathway and subsequently upregulates cell cycle regulators, cyclin D1/cyclin-dependent kinase (CDK) 6 and cyclin E1/CDK2 complex. The present study is the first to report that GPER-1 mediates BMSC proliferation. This finding indicates that GPER-1 mediated signaling positively regulates BMSC proliferation and may provide novel insights into addressing estrogen-mediated bone development.
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Affiliation(s)
- Shu-Chun Chuang
- Orthopaedic Research Center, Kaohsiung Medical University, Kaohsiung 807, Taiwan; (S.-C.C.); (C.-H.C.); (Y.-S.C.)
- Regenerative Medicine and Cell Therapy Research Center, Kaohsiung Medical University, Kaohsiung 807, Taiwan
| | - Chung-Hwan Chen
- Orthopaedic Research Center, Kaohsiung Medical University, Kaohsiung 807, Taiwan; (S.-C.C.); (C.-H.C.); (Y.-S.C.)
- Regenerative Medicine and Cell Therapy Research Center, Kaohsiung Medical University, Kaohsiung 807, Taiwan
- Department of Orthopedics, College of Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan
- Division of Adult Reconstruction Surgery, Department of Orthopedics, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung 807, Taiwan
- Department of Orthopedics, Kaohsiung Municipal Ta-Tung Hospital, Kaohsiung Medical University, Kaohsiung 807, Taiwan
- Institute of Medical Science and Technology, National Sun Yat-Sen University, Kaohsiung 807, Taiwan
| | - Ya-Shuan Chou
- Orthopaedic Research Center, Kaohsiung Medical University, Kaohsiung 807, Taiwan; (S.-C.C.); (C.-H.C.); (Y.-S.C.)
- Regenerative Medicine and Cell Therapy Research Center, Kaohsiung Medical University, Kaohsiung 807, Taiwan
| | - Mei-Ling Ho
- Orthopaedic Research Center, Kaohsiung Medical University, Kaohsiung 807, Taiwan; (S.-C.C.); (C.-H.C.); (Y.-S.C.)
- Regenerative Medicine and Cell Therapy Research Center, Kaohsiung Medical University, Kaohsiung 807, Taiwan
- Department of Medicinal Research, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung 807, Taiwan
- Department of Physiology, College of Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan
- Department of Marine Biotechnology and Resources, National Sun Yat-Sen University, Kaohsiung 807, Taiwan
- Correspondence: (M.-L.H.); (J.-K.C.); Tel.: +886-7-3121101-2553 (M.-L.H.&J.-K.C.); Fax: +886-7-3219452 (M.-L.H.&J.-K.C.)
| | - Je-Ken Chang
- Orthopaedic Research Center, Kaohsiung Medical University, Kaohsiung 807, Taiwan; (S.-C.C.); (C.-H.C.); (Y.-S.C.)
- Regenerative Medicine and Cell Therapy Research Center, Kaohsiung Medical University, Kaohsiung 807, Taiwan
- Department of Orthopedics, College of Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan
- Division of Adult Reconstruction Surgery, Department of Orthopedics, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung 807, Taiwan
- Correspondence: (M.-L.H.); (J.-K.C.); Tel.: +886-7-3121101-2553 (M.-L.H.&J.-K.C.); Fax: +886-7-3219452 (M.-L.H.&J.-K.C.)
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24
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Deng L, Guo Y. Estrogen effects on orthodontic tooth movement and orthodontically-induced root resorption. Arch Oral Biol 2020; 118:104840. [PMID: 32730908 DOI: 10.1016/j.archoralbio.2020.104840] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Revised: 06/21/2020] [Accepted: 07/08/2020] [Indexed: 02/08/2023]
Abstract
Estrogen is an essential regulator of the bone tissue. The remodeling of the alveolar bone and periodontal ligament is the basis of orthodontic tooth movement (OTM). There is a negative coregulation between physiological estrogen levels and the rate of OTM. As a possible inhibitory factor of OTM, estrogen suppresses bone resorption by inhibiting osteoclastic differentiation and restraining osteoclast lifespan though multiple pathways and cytokines, leading to the suppression of the initiation step of bone remodeling. On the other hand, estrogen stimulates osteoblastic differentiation and function. Estrogen receptor-α (ERα) involves in the osteogenic responses to mechanical stimulation, and the ERα expression is regulated positively by the levels of circulatory estrogen. Orthodontically induced root resorption (OIRR) is a common side-effect of orthodontic treatment. Estrogen may have some inhibitory effects on OIRR, but more studies are needed to get an effective conclusion.
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Affiliation(s)
- Lanzhi Deng
- State Key Laboratory of Oral Diseases & National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China
| | - Yongwen Guo
- State Key Laboratory of Oral Diseases & National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China; Department of Orthodontics, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China.
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25
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Galea GL, Delisser PJ, Meakin L, Price JS, Windahl SH. Bone gain following loading is site-specifically enhanced by prior and concurrent disuse in aged male mice. Bone 2020; 133:115255. [PMID: 31991251 PMCID: PMC7057260 DOI: 10.1016/j.bone.2020.115255] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Revised: 01/24/2020] [Accepted: 01/24/2020] [Indexed: 11/28/2022]
Abstract
The primary aim of osteoanabolic therapies is to strategically increase bone mass in skeletal regions likely to experience high strains. In the young healthy skeleton, this is primarily achieved by bone's adaptation to loading. This adaptation appears to fail with age, resulting in osteoporosis and fractures. We previously demonstrated that prior and concurrent disuse enhances bone gain following loading in old female mice. Here, we applied site specificity micro-computed tomography analysis to map regional differences in bone anabolic responses to axial loading of the tibia between young (19-week-old) and aged (19-month-old), male and female mice. Loading increased bone mass specifically in the proximal tibia in both sexes and ages. Young female mice gained more cortical bone than young males in specific regions of the tibia. However, these site-specific sex differences were lost with age such that bone gain following loading was not significantly different between old males and females. To test whether disuse enhances functional adaption in old male mice as it does in females, old males were subjected to sciatic neurectomy or sham surgery, and loading was initiated four days after surgery. Disuse augmented tibial cortical bone gain in response to loading in old males, but only in regions which were load-responsive in the young. Prior and concurrent disuse also increased loading-induced trabecular thickening in the proximal tibia of old males. Understanding how diminished background loading rejuvenates the osteogenic loading response in the old may improve osteogenic exercise regimes and lead to novel osteoanabolic therapies.
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Affiliation(s)
- Gabriel L Galea
- Developmental Biology and Cancer, UCL GOS Institute of Child Health, London, UK; Comparative Biomedical Sciences, Royal Veterinary College, London, UK.
| | - Peter J Delisser
- School of Veterinary Sciences, University of Bristol, Bristol, United Kingdom; Veterinary Specialist Services, Brisbane, Australia.
| | - Lee Meakin
- School of Veterinary Sciences, University of Bristol, Bristol, United Kingdom.
| | - Joanna S Price
- School of Veterinary Sciences, University of Bristol, Bristol, United Kingdom; Royal Agricultural University Cirencester, Cirencester, United Kingdom.
| | - Sara H Windahl
- School of Veterinary Sciences, University of Bristol, Bristol, United Kingdom; Department of Laboratory Medicine, Karolinska Institutet, Huddinge, Sweden.
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26
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Liphardt AM, Windahl SH, Sehic E, Hannemann N, Gustafsson KL, Bozec A, Schett G, Engdahl C. Changes in mechanical loading affect arthritis-induced bone loss in mice. Bone 2020; 131:115149. [PMID: 31715339 DOI: 10.1016/j.bone.2019.115149] [Citation(s) in RCA: 6] [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: 08/19/2019] [Revised: 11/04/2019] [Accepted: 11/06/2019] [Indexed: 12/15/2022]
Abstract
Arthritis induces bone loss by inflammation-mediated disturbance of bone homeostasis. On the other hand, pain and impaired locomotion are highly prevalent in arthritis and result in reduced general physical activity and less pronounced mechanical loading. Bone is affected by mechanical loading, directly through impact with the ground during movement and indirectly through muscular activity. Mechanical loading in its physiological range is essential for maintaining bone mass, whereas disuse leads to bone loss. The aim of this study was to investigate the impact of mechanical loading on periarticular bone as well as inflammation during arthritis. Mechanical loading was either blocked by botulinum neurotoxin A (Botox) injections before induction of arthritis, or enhanced by cyclic compressive loading, three times per week during arthritis induction. Arthritis was verified and evaluated histologically. Trabecular and cortical bone mass were investigated using micro-computed tomography (μCT), subchondral osteoclastogenesis and bone turnover was assessed by standard methods. Inhibition of mechanical loading enhanced arthritis-induced bone loss while it did not affect inflammation. In contrast, enhanced mechanical loading mitigated arthritis-induced bone loss. Furthermore, the increase in bone resorption markers by arthritis was partly blocked by mechanical loading. In conclusion, enhanced arthritic bone loss after abrogation of mechanical loading suggests that muscle forces play an essential role in preventing arthritic bone loss. In accordance, mechanical loading of the arthritic joints inhibited bone loss, emphasizing that weight bearing activities may have the potential to counteract arthritis-mediated bone loss.
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Affiliation(s)
- Anna-Maria Liphardt
- Friedrich-Alexander-University Erlangen-Nuremberg (FAU), Department of Internal Medicine 3 -Rheumatology & Immunology, University Hospital Erlangen, Erlangen, Germany; German Sport University Cologne (DSHS Köln), Institute of Biomechanics and Orthopedics, Köln, Germany
| | - Sara H Windahl
- Centre for Bone and Arthritis Research, Department of Internal Medicine and Clinical Nutrition, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden; Department of Laboratory Medicine, Division of Pathology, Karolinska Institutet, Karolinska University Hospital, Huddinge, Sweden
| | - Edina Sehic
- Centre for Bone and Arthritis Research, Department of Internal Medicine and Clinical Nutrition, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden; Centre for Bone and Arthritis Research, Department of Rheumatology and Inflammation Research, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Nicole Hannemann
- Friedrich-Alexander-University Erlangen-Nuremberg (FAU), Department of Internal Medicine 3 -Rheumatology & Immunology, University Hospital Erlangen, Erlangen, Germany
| | - Karin L Gustafsson
- Centre for Bone and Arthritis Research, Department of Internal Medicine and Clinical Nutrition, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Aline Bozec
- Friedrich-Alexander-University Erlangen-Nuremberg (FAU), Department of Internal Medicine 3 -Rheumatology & Immunology, University Hospital Erlangen, Erlangen, Germany
| | - Georg Schett
- Friedrich-Alexander-University Erlangen-Nuremberg (FAU), Department of Internal Medicine 3 -Rheumatology & Immunology, University Hospital Erlangen, Erlangen, Germany
| | - Cecilia Engdahl
- Friedrich-Alexander-University Erlangen-Nuremberg (FAU), Department of Internal Medicine 3 -Rheumatology & Immunology, University Hospital Erlangen, Erlangen, Germany; Centre for Bone and Arthritis Research, Department of Internal Medicine and Clinical Nutrition, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden; Centre for Bone and Arthritis Research, Department of Rheumatology and Inflammation Research, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
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27
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Matthews BG, Wee NKY, Widjaja VN, Price JS, Kalajzic I, Windahl SH. αSMA Osteoprogenitor Cells Contribute to the Increase in Osteoblast Numbers in Response to Mechanical Loading. Calcif Tissue Int 2020; 106:208-217. [PMID: 31673746 PMCID: PMC6995756 DOI: 10.1007/s00223-019-00624-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/14/2019] [Accepted: 10/11/2019] [Indexed: 01/11/2023]
Abstract
Bone is a dynamic tissue that site-specifically adapts to the load that it experiences. In response to increasing load, the cortical bone area is increased, mainly through enhanced periosteal bone formation. This increase in area is associated with an increase in the number of bone-forming osteoblasts; however, the origin of the cells involved remains unclear. Alpha-smooth muscle actin (αSMA) is a marker of early osteoprogenitor cells in the periosteum, and we hypothesized that the new osteoblasts that are activated by loading could originate from αSMA-expressing cells. Therefore, we used an in vivo fate-mapping approach in an established axial loading model to investigate the role of αSMA-expressing cells in the load-induced increase in osteoblasts. Histomorphometric analysis was applied to measure the number of cells of different origin on the periosteal surface in the most load-responsive region of the mouse tibia. A single loading session failed to increase the number of periosteal αSMA-expressing cells and osteoblasts. However, in response to multiple episodes of loading, the caudal, but not the cranial, periosteal surface was lined with an increased number of osteoblasts originating from αSMA-expressing cells 5 days after the initial loading session. The proportion of osteoblasts derived from αSMA-labeled progenitors increased by 70% (p < 0.05), and the proportion of αSMA-labeled cells that had differentiated into osteoblasts was doubled. We conclude that αSMA-expressing osteoprogenitors can differentiate and contribute to the increase in periosteal osteoblasts induced by mechanical loading in a site-specific manner.
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Affiliation(s)
- B G Matthews
- Department of Reconstructive Sciences, UConn Health, Farmington, CT, USA
- Department of Molecular Medicine and Pathology, University of Auckland, Auckland, New Zealand
| | - N K Y Wee
- Department of Reconstructive Sciences, UConn Health, Farmington, CT, USA
| | - V N Widjaja
- Department of Molecular Medicine and Pathology, University of Auckland, Auckland, New Zealand
| | - J S Price
- School of Veterinary Sciences, University of Bristol, Bristol, UK
- Royal Agricultural University, Cirencester, UK
| | - I Kalajzic
- Department of Reconstructive Sciences, UConn Health, Farmington, CT, USA
| | - S H Windahl
- School of Veterinary Sciences, University of Bristol, Bristol, UK.
- Division of Pathology, Department of Laboratory Medicine, Karolinska Institutet, Huddinge, Sweden.
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28
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Wu Y, Kadota-Watanabe C, Ogawa T, Moriyama K. Combination of estrogen deficiency and excessive mechanical stress aggravates temporomandibular joint osteoarthritis in vivo. Arch Oral Biol 2019; 102:39-46. [PMID: 30959278 DOI: 10.1016/j.archoralbio.2019.03.012] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2018] [Revised: 03/12/2019] [Accepted: 03/15/2019] [Indexed: 12/11/2022]
Abstract
OBJECTIVE It has been suggested that degenerative conditions of the temporomandibular joint (TMJ), such as osteoarthritis (OA) and progressive condylar resorption, are caused by multiple etiological factors, such as hormonal imbalance and excessive mechanical stress. However, it is unclear whether these factors interrelate in the degenerative process of the condyle. The aim of this study was to observe the effects of combined hormonal imbalance and excessive mechanical stress on the condyle using a mouse model. MATERIALS AND METHODS Ovariectomy (OVX) was performed in 8-week-old female mice. Three weeks after OVX, a build-up resin was bonded to the right maxillary molars to create imbalanced occlusion (increased occlusal vertical dimension, iOVD). Mice were divided into four groups: control, OVX, iOVD, and OVX + iOVD. RESULTS Histomorphometric analysis showed the lowest cartilage thickness and the highest TMJ-OA score in the OVX + iOVD group. Bone structural analysis showed significantly lower subchondral bone mass in all experimental groups. Additionally, the OVX + iOVD group showed up-regulated osteoclastic activity and increased apoptosis in the condyle. Gene expression analysis showed significantly elevated expression of pre-inflammatory cytokines in the OVX + iOVD group. These data showed that the OVX + iOVD group exhibited the most severe inflammatory TMJ-OA. Upregulation of ERα and activation of the ERK pathway was observed in the OVX + iOVD group. CONCLUSIONS Additive effects of estrogen deficiency and excessive mechanical stress on the condyle exacerbate TMJ-OA. Furthermore, estrogen deficiency and excessive mechanical stress combined may exacerbate TMJ-OA though activation of the ERK pathway.
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Affiliation(s)
- Yuyun Wu
- Department of Maxillofacial Orthognathics, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45, Yushima, Bunkyo-ku, Tokyo, 113-8549, Japan.
| | - Chiho Kadota-Watanabe
- Department of Maxillofacial Orthognathics, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45, Yushima, Bunkyo-ku, Tokyo, 113-8549, Japan.
| | - Takuya Ogawa
- Department of Maxillofacial Orthognathics, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45, Yushima, Bunkyo-ku, Tokyo, 113-8549, Japan.
| | - Keiji Moriyama
- Department of Maxillofacial Orthognathics, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45, Yushima, Bunkyo-ku, Tokyo, 113-8549, Japan.
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Lin Y, Xiao L, Zhang Y, Li P, Wu Y, Lin Y. MiR-26b-3p regulates osteoblast differentiation via targeting estrogen receptor α. Genomics 2018; 111:1089-1096. [PMID: 29981839 DOI: 10.1016/j.ygeno.2018.07.003] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2018] [Revised: 07/03/2018] [Accepted: 07/04/2018] [Indexed: 12/29/2022]
Abstract
BACKGROUND Understanding of the molecular mechanisms of miRNAs involved in osteoblast differentiation is important for the treatment of bone-related diseases. METHODS MC3T3-E1 cells were induced to osteogenic differentiation by culturing with bone morphogenetic protein 2 (BMP2). After transfected with miR-26b-3p mimics or inhibitors, the osteogenic differentiation of MC3T3-E1 cells was detected by ALP and ARS staining. Cell viability was analyzed by MTT. The expressions of miR-26b-3p and osteogenic related markers and signaling were examined by qPCR and western blot. Direct binding of miR-26b-3p and ER-α were determined by dual luciferase assay. RESULTS miR-26b-3p was significantly down-regulated during osteoblast differentiation. Overexpression of miR-26b-3p inhibited osteoblast differentiation, while inhibition of miR-26b-3p enhanced osteoblast differentiation. Further studies demonstrated miR-26b-3p inhibited the expression of estrogen receptor α (ER-α) by directly targeting to the CDS region of ER-α mRNA. Overexpression of ER-α rescued the suppression effects of miR-26b-3p on osteoblast differentiation, while knockdown of ER-α reversed the upregulation of osteoblast differentiation induced by knockdown of miR-26b-3p. CONCLUSION Our study demonstrates that miR-26b-3p suppresses osteoblast differentiation of MC3T3-E1 cells via directly targeting ER-α.
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Affiliation(s)
- Yu Lin
- Department of Orthopaedics, The Second Hospital of Fuzhou Affiliated to Xiamen University, Fuzhou 350007, PR China.
| | - Lili Xiao
- Department of Orthopaedics, The Second Hospital of Fuzhou Affiliated to Xiamen University, Fuzhou 350007, PR China
| | - Yiyuan Zhang
- Department of Orthopaedics, The Second Hospital of Fuzhou Affiliated to Xiamen University, Fuzhou 350007, PR China
| | - Ping Li
- Department of Orthopaedics, The Second Hospital of Fuzhou Affiliated to Xiamen University, Fuzhou 350007, PR China
| | - Yinsheng Wu
- Institute of osteopathy, Fujian Traditional Chinese Medicine University Integrated Traditional Chinese, Western Medicine Research Institute, Fuzhou 350102, PR China
| | - Yanping Lin
- Institute of osteopathy, Fujian Traditional Chinese Medicine University Integrated Traditional Chinese, Western Medicine Research Institute, Fuzhou 350102, PR China.
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Bergström I, Isaksson H, Koskela A, Tuukkanen J, Ohlsson C, Andersson G, Windahl SH. Prednisolone treatment reduces the osteogenic effects of loading in mice. Bone 2018; 112:10-18. [PMID: 29635039 DOI: 10.1016/j.bone.2018.04.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Revised: 04/04/2018] [Accepted: 04/05/2018] [Indexed: 11/25/2022]
Abstract
Glucocorticoid treatment, a major cause of drug-induced osteoporosis and fractures, is widely used to treat inflammatory conditions and diseases. By contrast, mechanical loading increases bone mass and decreases fracture risk. With these relationships in mind, we investigated whether mechanical loading interacts with GC treatment in bone. Three-month-old female C57BL/6 mice were treated with high-dose prednisolone (15 mg/60 day pellets/mouse) or vehicle for two weeks. During the treatment, right tibiae were subjected to short periods of cyclic compressive loading three times weekly, while left tibiae were used as physiologically loaded controls. The bones were analyzed using peripheral quantitative computed tomography, histomorphometry, real-time PCR, three-point bending and Fourier transform infrared micro-spectroscopy. Loading alone increased trabecular volumetric bone mineral density (vBMD), cortical thickness, cortical area, osteoblast-associated gene expression, osteocyte- and osteoclast number, and bone strength. Prednisolone alone decreased cortical area and thickness and osteoblast-associated gene expression. Importantly, prednisolone treatment decreased the load-induced increase in trabecular vBMD by 57% (p < 0.001) and expression of osteoblast-associated genes, while completely abolishing the load-induced increase in cortical area, cortical thickness, number of osteocytes and osteoclasts, and bone strength. When combined, loading and prednisolone decreased the collagen content. In conclusion, high-dose prednisolone treatment strongly inhibits the loading-induced increase in trabecular BMD, and abolishes the loading-induced increase in cortical bone mass. This phenomenon could be due to prednisolone inhibition of osteoblast differentiation and function.
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Affiliation(s)
- I Bergström
- Department of Endocrinology, Metabolism and Diabetes, Karolinska University Hospital, CLINTECH, Karolinska Institutet, Huddinge, Sweden
| | - H Isaksson
- Department of Biomedical Engineering, Lund University, Lund, Sweden
| | - A Koskela
- Department of Anatomy and Cell Biology, Institute of Biomedicine, University of Oulu, Oulu, Finland
| | - J Tuukkanen
- Department of Anatomy and Cell Biology, Institute of Biomedicine, University of Oulu, Oulu, Finland
| | - C Ohlsson
- Centre for Bone and Arthritis Research, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - G Andersson
- Department of Laboratory Medicine, Karolinska Institutet, Huddinge, Sweden
| | - S H Windahl
- Centre for Bone and Arthritis Research, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden; Department of Laboratory Medicine, Division of Pathology, Karolinska Institutet, F46, Karolinska University Hospital, 141 86 Huddinge, Sweden.
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31
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Haffner-Luntzer M, Kovtun A, Lackner I, Mödinger Y, Hacker S, Liedert A, Tuckermann J, Ignatius A. Estrogen receptor α- (ERα), but not ERβ-signaling, is crucially involved in mechanostimulation of bone fracture healing by whole-body vibration. Bone 2018; 110:11-20. [PMID: 29367057 DOI: 10.1016/j.bone.2018.01.017] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Revised: 12/21/2017] [Accepted: 01/14/2018] [Indexed: 02/07/2023]
Abstract
Mechanostimulation by low-magnitude high frequency vibration (LMHFV) has been shown to provoke anabolic effects on the intact skeleton in both mice and humans. However, experimental studies revealed that, during bone fracture healing, the effect of whole-body vibration is profoundly influenced by the estrogen status. LMHFV significantly improved fracture healing in ovariectomized (OVX) mice being estrogen deficient, whereas bone regeneration was significantly reduced in non-OVX, estrogen-competent mice. Furthermore, estrogen receptors α (ERα) and β (ERβ) were differentially expressed in the fracture callus after whole-body vibration, depending on the estrogen status. Based on these data, we hypothesized that ERs may mediate vibration-induced effects on fracture healing. To prove this hypothesis, we investigated the effects of LMHFV on bone healing in mice lacking ERα or ERβ. To study the influence of the ER ligand estrogen, both non-OVX and OVX mice were used. All mice received a femur osteotomy stabilized by an external fixator. Half of the mice were sham-operated or subjected to OVX 4 weeks before osteotomy. Half of each group received LMHFV with 0.3 g and 45 Hz for 20 min per day, 5 days per week. After 21 days, fracture healing was evaluated by biomechanical testing, μCT analysis, histomorphometry and immunohistochemistry. Absence of ERα or ERβ did not affect fracture healing in sham-treated mice. Wildtype (WT) and ERβ-knockout mice similarly displayed impaired bone regeneration after OVX, whereas ERα-knockout mice did not. Confirming previous data, in WT mice, LMHFV negatively affected bone repair in non-OVX mice, whereas OVX-induced compromised healing was significantly improved by vibration. In contrast, vibrated ERα-knockout mice did not display significant differences in fracture healing compared to non-vibrated animals, both in non-OVX and OVX mice. Fracture healing in ERβ-knockout mice was similarly affected by LMHFV as in WT mice. These results suggest that ERα-signaling may be crucial for vibration-induced effects on fracture healing, whereas ERβ-signaling may play a minor role.
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Affiliation(s)
- Melanie Haffner-Luntzer
- Institute of Orthopedic Research and Biomechanics, University Medical Center Ulm, Helmholtzstraße 14, 89081 Ulm, Germany.
| | - Anna Kovtun
- Institute of Orthopedic Research and Biomechanics, University Medical Center Ulm, Helmholtzstraße 14, 89081 Ulm, Germany
| | - Ina Lackner
- Institute of Orthopedic Research and Biomechanics, University Medical Center Ulm, Helmholtzstraße 14, 89081 Ulm, Germany
| | - Yvonne Mödinger
- Institute of Orthopedic Research and Biomechanics, University Medical Center Ulm, Helmholtzstraße 14, 89081 Ulm, Germany
| | - Steffen Hacker
- Institute of Orthopedic Research and Biomechanics, University Medical Center Ulm, Helmholtzstraße 14, 89081 Ulm, Germany
| | - Astrid Liedert
- Institute of Orthopedic Research and Biomechanics, University Medical Center Ulm, Helmholtzstraße 14, 89081 Ulm, Germany
| | - Jan Tuckermann
- Institute of Comparative Molecular Endocrinology, Ulm University, Helmholtzstraße 8, 89081 Ulm, Germany
| | - Anita Ignatius
- Institute of Orthopedic Research and Biomechanics, University Medical Center Ulm, Helmholtzstraße 14, 89081 Ulm, Germany
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32
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Ansari N, Ho PW, Crimeen-Irwin B, Poulton IJ, Brunt AR, Forwood MR, Divieti Pajevic P, Gooi JH, Martin TJ, Sims NA. Autocrine and Paracrine Regulation of the Murine Skeleton by Osteocyte-Derived Parathyroid Hormone-Related Protein. J Bone Miner Res 2018; 33:137-153. [PMID: 28914969 DOI: 10.1002/jbmr.3291] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/28/2017] [Revised: 08/28/2017] [Accepted: 09/06/2017] [Indexed: 12/14/2022]
Abstract
Parathyroid hormone-related protein (PTHrP) and parathyroid hormone (PTH) have N-terminal domains that bind a common receptor, PTHR1. N-terminal PTH (teriparatide) and now a modified N-terminal PTHrP (abaloparatide) are US Food and Drug Administration (FDA)-approved therapies for osteoporosis. In physiology, PTHrP does not normally circulate at significant levels, but acts locally, and osteocytes, cells residing within the bone matrix, express both PTHrP and the PTHR1. Because PTHR1 in osteocytes is required for normal bone resorption, we determined how osteocyte-derived PTHrP influences the skeleton. We observed that adult mice with low PTHrP in osteocytes (targeted with the Dmp1(10kb)-Cre) have low trabecular bone volume and osteoblast numbers, but osteoclast numbers were unaffected. In addition, bone size was normal, but cortical bone strength was impaired. Osteocyte-derived PTHrP therefore stimulates bone formation and bone matrix strength, but is not required for normal osteoclastogenesis. PTHrP knockdown and overexpression studies in cultured osteocytes indicate that osteocyte-secreted PTHrP regulates their expression of genes involved in matrix mineralization. We determined that osteocytes secrete full-length PTHrP with no evidence for secretion of lower molecular weight forms containing the N-terminus. We conclude that osteocyte-derived full-length PTHrP acts through both PTHR1 receptor-mediated and receptor-independent actions in a paracrine/autocrine manner to stimulate bone formation and to modify adult cortical bone strength. © 2017 American Society for Bone and Mineral Research.
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Affiliation(s)
- Niloufar Ansari
- St. Vincent's Institute of Medical Research, Fitzroy, Victoria, Australia.,The University of Melbourne, Department of Medicine at St. Vincent's Hospital, Fitzroy, Victoria, Australia
| | - Patricia Wm Ho
- St. Vincent's Institute of Medical Research, Fitzroy, Victoria, Australia
| | | | - Ingrid J Poulton
- St. Vincent's Institute of Medical Research, Fitzroy, Victoria, Australia
| | - Athena R Brunt
- School of Medical Science and Menzies Health Institute Queensland, Griffith University, Gold Coast, Queensland, Australia
| | - Mark R Forwood
- School of Medical Science and Menzies Health Institute Queensland, Griffith University, Gold Coast, Queensland, Australia
| | - Paola Divieti Pajevic
- Department of Molecular and Cell Biology, Boston University Goldman School of Dental Medicine, Boston, MA, USA
| | - Jonathan H Gooi
- The University of Melbourne, Department of Medicine at St. Vincent's Hospital, Fitzroy, Victoria, Australia
| | - T John Martin
- St. Vincent's Institute of Medical Research, Fitzroy, Victoria, Australia.,The University of Melbourne, Department of Medicine at St. Vincent's Hospital, Fitzroy, Victoria, Australia
| | - Natalie A Sims
- St. Vincent's Institute of Medical Research, Fitzroy, Victoria, Australia.,The University of Melbourne, Department of Medicine at St. Vincent's Hospital, Fitzroy, Victoria, Australia
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33
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Rooney AM, van der Meulen MCH. Mouse models to evaluate the role of estrogen receptor α in skeletal maintenance and adaptation. Ann N Y Acad Sci 2017; 1410:85-92. [PMID: 29148577 DOI: 10.1111/nyas.13523] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2017] [Revised: 09/11/2017] [Accepted: 09/13/2017] [Indexed: 12/15/2022]
Abstract
Estrogen signaling and mechanical loading have individual and combined effects on skeletal maintenance and adaptation. Previous work investigating estrogen signaling both in vitro and in vivo using global estrogen receptor α (ERα) gene knockout mouse models has provided information regarding the role of ERα in regulating bone mass and adaptation to mechanical stimulation. However, these models have inherent limitations that confound interpretation of the data. Therefore, recent studies have focused on mice with targeted deletion of ERα from specific bone cells and their precursors. Cell stage, tissue type, and mouse sex all influence the effects of ERα gene deletion. Lack of ERα in osteoblast progenitor and precursor cells generally affects the periosteum of female and male mice. The absence of ERα in differentiated osteoblasts, osteocytes, and osteoclasts in mice generally resulted in reduced cancellous bone mass, with differing reports of the effect by animal sex and greater deficiencies in bone mass typically occurring in cancellous bone in female mice. Limited data exist for the role of bone cell-specific ERα in skeletal adaptation in vivo. Cell-specific ERα gene knockout mice provide an excellent platform for investigating the function of ERα in regulating skeletal phenotype and response to mechanical loading by sex and age.
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Affiliation(s)
- Amanda M Rooney
- Nancy E. and Peter C. Meinig School of Biomedical Engineering, Cornell University, Ithaca, New York
| | - Marjolein C H van der Meulen
- Nancy E. and Peter C. Meinig School of Biomedical Engineering, Cornell University, Ithaca, New York.,Sibley School of Mechanical and Aerospace Engineering, Cornell University, Ithaca, New York.,Research Division, Hospital for Special Surgery, New York, New York
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34
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Cho DC, Brennan HJ, Johnson RW, Poulton IJ, Gooi JH, Tonkin BA, McGregor NE, Walker EC, Handelsman DJ, Martin TJ, Sims NA. Bone corticalization requires local SOCS3 activity and is promoted by androgen action via interleukin-6. Nat Commun 2017; 8:806. [PMID: 28993616 PMCID: PMC5634449 DOI: 10.1038/s41467-017-00920-x] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Accepted: 08/07/2017] [Indexed: 01/12/2023] Open
Abstract
Long bone strength is determined by its outer shell (cortical bone), which forms by coalescence of thin trabeculae at the metaphysis (corticalization), but the factors that control this process are unknown. Here we show that SOCS3-dependent cytokine expression regulates bone corticalization. Young male and female Dmp1Cre.Socs3 f/f mice, in which SOCS3 has been ablated in osteocytes, have high trabecular bone volume and poorly defined metaphyseal cortices. After puberty, male mice recover, but female corticalization is still impaired, leading to a lasting defect in bone strength. The phenotype depends on sex-steroid hormones: dihydrotestosterone treatment of gonadectomized female Dmp1Cre.Socs3 f/f mice restores normal cortical morphology, whereas in males, estradiol treatment, or IL-6 deletion, recapitulates the female phenotype. This suggests that androgen action promotes metaphyseal corticalization, at least in part, via IL-6 signaling.The strength of long bones is determined by coalescence of trabeculae during corticalization. Here the authors show that this process is regulated by SOCS3 via a mechanism dependent on IL-6 and expression of sex hormones.
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Affiliation(s)
- Dae-Chul Cho
- St. Vincent's Institute of Medical Research, 9 Princes Street, Fitzroy, VIC, 3065, Australia.,Department of Neurosurgery, Kyungpook National University Hospital, 130 Dongdukro, Jung-gu, Daegu, 41944, Republic of Korea
| | - Holly J Brennan
- St. Vincent's Institute of Medical Research, 9 Princes Street, Fitzroy, VIC, 3065, Australia.,Department of Medicine at St. Vincent's Hospital, University of Melbourne, 41 Victoria Parade, Fitzroy, VIC, 3065, Australia
| | - Rachelle W Johnson
- St. Vincent's Institute of Medical Research, 9 Princes Street, Fitzroy, VIC, 3065, Australia.,Division of Clinical Pharmacology, Vanderbilt University, 2215 Garland Avenue, 1255B MRB IV, Nashville, TN, 37212, USA
| | - Ingrid J Poulton
- St. Vincent's Institute of Medical Research, 9 Princes Street, Fitzroy, VIC, 3065, Australia
| | - Jonathan H Gooi
- Department of Medicine at St. Vincent's Hospital, University of Melbourne, 41 Victoria Parade, Fitzroy, VIC, 3065, Australia
| | - Brett A Tonkin
- St. Vincent's Institute of Medical Research, 9 Princes Street, Fitzroy, VIC, 3065, Australia
| | - Narelle E McGregor
- St. Vincent's Institute of Medical Research, 9 Princes Street, Fitzroy, VIC, 3065, Australia
| | - Emma C Walker
- St. Vincent's Institute of Medical Research, 9 Princes Street, Fitzroy, VIC, 3065, Australia
| | - David J Handelsman
- Department of Andrology, ANZAC Research Institute, University of Sydney, 3 Hospital Road, Concord, NSW, 2139, Australia
| | - T J Martin
- St. Vincent's Institute of Medical Research, 9 Princes Street, Fitzroy, VIC, 3065, Australia.,Department of Medicine at St. Vincent's Hospital, University of Melbourne, 41 Victoria Parade, Fitzroy, VIC, 3065, Australia
| | - Natalie A Sims
- St. Vincent's Institute of Medical Research, 9 Princes Street, Fitzroy, VIC, 3065, Australia. .,Department of Medicine at St. Vincent's Hospital, University of Melbourne, 41 Victoria Parade, Fitzroy, VIC, 3065, Australia.
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35
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Gregory KJ, Morin SM, Schneider SS. Regulation of early growth response 2 expression by secreted frizzled related protein 1. BMC Cancer 2017; 17:473. [PMID: 28687085 PMCID: PMC5501954 DOI: 10.1186/s12885-017-3426-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2016] [Accepted: 06/12/2017] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND Secreted frizzled-related protein 1 (SFRP1) expression is down-regulated in a multitude of cancers, including breast cancer. Loss of Sfrp1 also exacerbates weight gain as well as inflammation. Additionally, loss of SFRP1 enhances TGF-β signaling and the downstream MAPK pathway. TGF-β has been shown to increase the expression of Early Growth Response 2 (EGR2), a transcription factor implicated in immune function in a wide variety of cell types. The work described here was initiated to determine whether SFRP1 modulation affects TGF-β mediated EGR2 expression in mammary tissues as well as macrophage polarization. METHODS Real-time PCR analysis was performed to examine EGR2 expression in human and murine mammary epithelial cells and tissues in response to SFRP1 modulation. Chemical inhibition was employed to investigate the roles TGF-β and MAPK signaling play in the control of EGR2 expression in response to SFRP1 loss. Primary murine macrophages were isolated from Sfrp1-/- mice and stimulated to become either M1 or M2 macrophages, treated with recombinant SFRP1, and real-time PCR was used to measure the expression of murine specific M1/M2 markers [Egr2 (M2) and Gpr18 (M1)]. Immunohistochemical analysis was used to measure the expression of human specific M1/M2 markers [CD163 (M2) and HLA-DRA (M2)] in response to rSFRP1 treatment in human mammary explant tissue. RESULTS Knockdown of SFRP1 expression increases the expression of EGR2 mRNA in human mammary epithelial cells and addition of rSFRP1 decreases the expression of EGR2 when added to explant mammary gland tissues. Chemical inhibition of both TGF-β and MAPK signaling in Sfrp1-/- or knockdown mammary epithelial cells results in decreased expression of EGR2. Stimulated murine macrophages obtained from Sfrp1-/- mice and treated with rSFRP1 exhibit a reduction in Egr2 expression and an increase in Gpr18 mRNA expression. Human mammary explant tissue treated with rSFRP1 decreases CD163 protein expression whereas there was no effect on the expression of HLA-DRA. CONCLUSIONS Loss of SFRP1 likely contributes to tumor progression by altering the expression of a critical transcription factor in both the epithelium and the immune system.
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Affiliation(s)
- Kelly J Gregory
- Pioneer Valley Life Sciences Institute, Baystate Medical Center, 3601 Main St, Springfield, MA, 01199, USA. .,Department of Biology, University of Massachusetts, Amherst, MA, 01003, USA.
| | - Stephanie M Morin
- Department of Biology, University of Massachusetts, Amherst, MA, 01003, USA
| | - Sallie S Schneider
- Pioneer Valley Life Sciences Institute, Baystate Medical Center, 3601 Main St, Springfield, MA, 01199, USA. .,Veterinary and Animal Sciences, University of Massachusetts, Amherst, MA, 01003, USA.
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36
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Bergström I, Kerns JG, Törnqvist AE, Perdikouri C, Mathavan N, Koskela A, Henriksson HB, Tuukkanen J, Andersson G, Isaksson H, Goodship AE, Windahl SH. Compressive loading of the murine tibia reveals site-specific micro-scale differences in adaptation and maturation rates of bone. Osteoporos Int 2017; 28:1121-1131. [PMID: 27921145 PMCID: PMC5306148 DOI: 10.1007/s00198-016-3846-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Accepted: 11/16/2016] [Indexed: 01/16/2023]
Abstract
Loading increases bone mass and strength in a site-specific manner; however, possible effects of loading on bone matrix composition have not been evaluated. Site-specific structural and material properties of mouse bone were analyzed on the macro- and micro/molecular scale in the presence and absence of axial loading. The response of bone to load is heterogeneous, adapting at molecular, micro-, and macro-levels. INTRODUCTION Osteoporosis is a degenerative disease resulting in reduced bone mineral density, structure, and strength. The overall aim was to explore the hypothesis that changes in loading environment result in site-specific adaptations at molecular/micro- and macro-scale in mouse bone. METHODS Right tibiae of adult mice were subjected to well-defined cyclic axial loading for 2 weeks; left tibiae were used as physiologically loaded controls. The bones were analyzed with μCT (structure), reference point indentation (material properties), Raman spectroscopy (chemical), and small-angle X-ray scattering (mineral crystallization and structure). RESULTS The cranial and caudal sites of tibiae are structurally and biochemically different within control bones. In response to loading, cranial and caudal sites increase in cortical thickness with reduced mineralization (-14 and -3%, p < 0.01, respectively) and crystallinity (-1.4 and -0.3%, p < 0.05, respectively). Along the length of the loaded bones, collagen content becomes more heterogeneous on the caudal site and the mineral/collagen increases distally at both sites. CONCLUSION Bone structure and composition are heterogeneous, finely tuned, adaptive, and site-specifically responsive at the micro-scale to maintain optimal function. Manipulation of this heterogeneity may affect bone strength, relative to specific applied loads.
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Affiliation(s)
- I Bergström
- Department of Endocrinology, Metabolism and Diabetes, Karolinska University Hospital, Karolinska Institutet, Stockholm, Sweden
| | - J G Kerns
- UCL Institute of Orthopedics and Musculoskeletal Science, Royal National Orthopedic Hospital, London, UK
- Lancaster Medical School, Faculty of Health and Medicine, Lancaster University, Lancaster, LA1 4YG, UK
| | - A E Törnqvist
- Rheumatology and Bone Diseases Unit, Centre for Genomic and Experimental Medicine, MRC Institute of Genetics and Molecular Medicine, Western General Hospital, University of Edinburgh, Edinburgh, EH4 2XU, UK
| | - C Perdikouri
- Department of Biomedical Engineering and Department of Orthopedics, Lund University, Lund, Sweden
| | - N Mathavan
- Department of Biomedical Engineering and Department of Orthopedics, Lund University, Lund, Sweden
| | - A Koskela
- Institute of Cancer and Translational Medicine, Department of Anatomy and Cell Biology, MRC Oulu, University of Oulu, Oulu, Finland
| | - H B Henriksson
- Department of Orthopedics, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
- Department of Orthopedics, Sahlgrenska University Hospital, Gothenburg, Sweden
| | - J Tuukkanen
- Institute of Cancer and Translational Medicine, Department of Anatomy and Cell Biology, MRC Oulu, University of Oulu, Oulu, Finland
| | - G Andersson
- Department of Laboratory Medicine, Division of Pathology, Karolinska University Hospital, Karolinska Institutet, Huddinge, Stockholm, Sweden
| | - H Isaksson
- Department of Biomedical Engineering and Department of Orthopedics, Lund University, Lund, Sweden
| | - A E Goodship
- UCL Institute of Orthopedics and Musculoskeletal Science, Royal National Orthopedic Hospital, London, UK
- Centre for Comparative and Clinical Anatomy, School of Veterinary Science, University of Bristol, Bristol, UK
| | - S H Windahl
- Centre for Bone and Arthritis Research, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
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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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38
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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. [PMID: 27807202 DOI: 10.1152/physrev.00033] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/29/2023] 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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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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Laurent MR, Dubois V, Claessens F, Verschueren SMP, Vanderschueren D, Gielen E, Jardí F. Muscle-bone interactions: From experimental models to the clinic? A critical update. Mol Cell Endocrinol 2016; 432:14-36. [PMID: 26506009 DOI: 10.1016/j.mce.2015.10.017] [Citation(s) in RCA: 91] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/31/2015] [Revised: 10/13/2015] [Accepted: 10/20/2015] [Indexed: 02/06/2023]
Abstract
Bone is a biomechanical tissue shaped by forces from muscles and gravitation. Simultaneous bone and muscle decay and dysfunction (osteosarcopenia or sarco-osteoporosis) is seen in ageing, numerous clinical situations including after stroke or paralysis, in neuromuscular dystrophies, glucocorticoid excess, or in association with vitamin D, growth hormone/insulin like growth factor or sex steroid deficiency, as well as in spaceflight. Physical exercise may be beneficial in these situations, but further work is still needed to translate acceptable and effective biomechanical interventions like vibration therapy from animal models to humans. Novel antiresorptive and anabolic therapies are emerging for osteoporosis as well as drugs for sarcopenia, cancer cachexia or muscle wasting disorders, including antibodies against myostatin or activin receptor type IIA and IIB (e.g. bimagrumab). Ideally, increasing muscle mass would increase muscle strength and restore bone loss from disuse. However, the classical view that muscle is unidirectionally dominant over bone via mechanical loading is overly simplistic. Indeed, recent studies indicate a role for neuronal regulation of not only muscle but also bone metabolism, bone signaling pathways like receptor activator of nuclear factor kappa-B ligand (RANKL) implicated in muscle biology, myokines affecting bone and possible bone-to-muscle communication. Moreover, pharmacological strategies inducing isolated myocyte hypertrophy may not translate into increased muscle power because tendons, connective tissue, neurons and energy metabolism need to adapt as well. We aim here to critically review key musculoskeletal molecular pathways involved in mechanoregulation and their effect on the bone-muscle unit as a whole, as well as preclinical and emerging clinical evidence regarding the effects of sarcopenia therapies on osteoporosis and vice versa.
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Affiliation(s)
- Michaël R Laurent
- Gerontology and Geriatrics, Department of Clinical and Experimental Medicine, KU Leuven, 3000 Leuven, Belgium; Laboratory of Molecular Endocrinology, Department of Cellular and Molecular Medicine, KU Leuven, 3000 Leuven, Belgium; Centre for Metabolic Bone Diseases, University Hospitals Leuven, 3000 Leuven, Belgium.
| | - Vanessa Dubois
- Laboratory of Molecular Endocrinology, Department of Cellular and Molecular Medicine, KU Leuven, 3000 Leuven, Belgium
| | - Frank Claessens
- Laboratory of Molecular Endocrinology, Department of Cellular and Molecular Medicine, KU Leuven, 3000 Leuven, Belgium
| | - Sabine M P Verschueren
- Research Group for Musculoskeletal Rehabilitation, Department of Rehabilitation Science, KU Leuven, 3000 Leuven, Belgium
| | - Dirk Vanderschueren
- Clinical and Experimental Endocrinology, Department of Clinical and Experimental Medicine, KU Leuven, 3000 Leuven, Belgium
| | - Evelien Gielen
- Gerontology and Geriatrics, Department of Clinical and Experimental Medicine, KU Leuven, 3000 Leuven, Belgium; Centre for Metabolic Bone Diseases, University Hospitals Leuven, 3000 Leuven, Belgium
| | - Ferran Jardí
- Clinical and Experimental Endocrinology, Department of Clinical and Experimental Medicine, KU Leuven, 3000 Leuven, Belgium
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The molecular basis of bone mechanotransduction. JOURNAL OF MUSCULOSKELETAL & NEURONAL INTERACTIONS 2016; 16:221-36. [PMID: 27609037 PMCID: PMC5114345] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The skeleton has the ability to perfectly adapt to external forces of the operating environment, by altering its morphology and metabolism in order to meet different needs. This unique adaptive capacity of the skeleton creates an interesting range of biological questions concerning the perception of mechanical or other kinds of signals, the type of receptor, and the molecular pathways involved in this adaptation. Studies of the characteristics of the cellular engineering provide a host of new information that confers to osteocytes the role of the protagonist in the perception and regulation of mechanical effects on the skeleton. The identity of mechanoreceptors is manifold and concerns ion channels, integrins, cell membrane, the cytoskeleton, and other systems. A similar multiplicity characterizes the intracellular signaling. This review describes recent data concerning the outward force reception systems and intracellular transduction pathways of information transfer leading to the continuous adaptation of bone tissue. Increased appreciation of the importance of the mechanical environment in regulating and determining the effectiveness of structural adjustment of the skeleton defines new horizons for the discovery of novel therapeutic approaches to diseases associated with bone loss.
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Svensson J, Windahl SH, Saxon L, Sjögren K, Koskela A, Tuukkanen J, Ohlsson C. Liver-derived IGF-I regulates cortical bone mass but is dispensable for the osteogenic response to mechanical loading in female mice. Am J Physiol Endocrinol Metab 2016; 311:E138-44. [PMID: 27221117 DOI: 10.1152/ajpendo.00107.2016] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/18/2016] [Accepted: 05/17/2016] [Indexed: 01/29/2023]
Abstract
Low circulating IGF-I is associated with increased fracture risk. Conditional depletion of IGF-I produced in osteoblasts or osteocytes inhibits the bone anabolic effect of mechanical loading. Here, we determined the role of endocrine IGF-I for the osteogenic response to mechanical loading in young adult and old female mice with adult, liver-specific IGF-I inactivation (LI-IGF-I(-/-) mice, serum IGF-I reduced by ≈70%) and control mice. The right tibia was subjected to short periods of axial cyclic compressive loading three times/wk for 2 wk, and measurements were performed using microcomputed tomography and mechanical testing by three-point bending. In the nonloaded left tibia, the LI-IGF-I(-/-) mice had lower cortical bone area and increased cortical porosity, resulting in reduced bone mechanical strength compared with the controls. Mechanical loading induced a similar response in LI-IGF-I(-/-) and control mice in terms of cortical bone area and trabecular bone volume fraction. In fact, mechanical loading produced a more marked increase in cortical bone mechanical strength, which was associated with a less marked increase in cortical porosity, in the LI-IGF-I(-/-) mice compared with the control mice. In conclusion, liver-derived IGF-I regulates cortical bone mass, cortical porosity, and mechanical strength under normal (nonloaded) conditions. However, despite an ∼70% reduction in circulating IGF-I, the osteogenic response to mechanical loading was not attenuated in the LI-IGF-I(-/-) mice.
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Affiliation(s)
- Johan Svensson
- Centre for Bone and Arthritis Research, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden;
| | - Sara H Windahl
- Centre for Bone and Arthritis Research, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden; School of Veterinary Sciences, Bristol United Kingdom
| | - Leanne Saxon
- The Royal Veterinary College, London United Kingdom; and
| | - 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, Institute of Cancer Research and Translational Medicine, Medical Research Center, University of Oulu, Oulu, Finland
| | - Juha Tuukkanen
- Department of Anatomy and Cell Biology, Institute of Cancer Research and Translational Medicine, Medical Research Center, University of Oulu, Oulu, Finland
| | - Claes Ohlsson
- Centre for Bone and Arthritis Research, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
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Börjesson AE, Farman HH, Movérare-Skrtic S, Engdahl C, Antal MC, Koskela A, Tuukkanen J, Carlsten H, Krust A, Chambon P, Sjögren K, Lagerquist MK, Windahl SH, Ohlsson C. SERMs have substance-specific effects on bone, and these effects are mediated via ERαAF-1 in female mice. Am J Physiol Endocrinol Metab 2016; 310:E912-8. [PMID: 27048997 PMCID: PMC4935145 DOI: 10.1152/ajpendo.00488.2015] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Accepted: 04/01/2016] [Indexed: 11/22/2022]
Abstract
The bone-sparing effect of estrogens is mediated primarily via estrogen receptor (ER)α, which stimulates gene transcription through activation function (AF)-1 and AF-2. The role of ERαAF-1 for the estradiol (E2) effects is tissue specific. The selective ER modulators (SERMs) raloxifene (Ral), lasofoxifene (Las), and bazedoxifene (Bza) can be used to treat postmenopausal osteoporosis. They all reduce the risk for vertebral fractures, whereas Las and partly Bza, but not Ral, reduce the risk for nonvertebral fractures. Here, we have compared the tissue specificity of Ral, Las, and Bza and evaluated the role of ERαAF-1 for the effects of these SERMs, with an emphasis on bone parameters. We treated ovariectomized (OVX) wild-type (WT) mice and OVX mice lacking ERαAF-1 (ERαAF-1(0)) with E2, Ral, Las, or Bza. All three SERMs increased trabecular bone mass in the axial skeleton. In the appendicular skeleton, only Las increased the trabecular bone volume/tissue volume and trabecular number, whereas both Ral and Las increased the cortical bone thickness and strength. However, Ral also increased cortical porosity. The three SERMs had only a minor effect on uterine weight. Notably, all evaluated effects of these SERMs were absent in ovx ERαAF-1(0) mice. In conclusion, all SERMs had similar effects on axial bone mass. However, the SERMs had slightly different effects on the appendicular skeleton since only Las increased the trabecular bone mass and only Ral increased the cortical porosity. Importantly, all SERM effects require a functional ERαAF-1 in female mice. These results could lead to development of more specific treatments for osteoporosis.
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Affiliation(s)
- Anna E Börjesson
- Rheumatology and Bone Diseases Unit, Centre for Genomic and Experimental Medicine, MRC Institute of Genetics and Molecular Medicine, Western General Hospital, University of Edinburgh, Edinburgh, United Kingdom
| | - Helen H Farman
- Centre for Bone and Arthritis Research, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Sofia Movérare-Skrtic
- Centre for Bone and Arthritis Research, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Cecilia Engdahl
- Centre for Bone and Arthritis Research, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Maria Cristina Antal
- Strasbourg University, Faculté de Médecine, Institut d'Histologie, Strasbourg, France
| | - Antti Koskela
- Department of Anatomy and Cell Biology, MRC Oulu, University of Oulu, Oulu, Finland
| | - Juha Tuukkanen
- Department of Anatomy and Cell Biology, MRC Oulu, University of Oulu, Oulu, Finland
| | - Hans Carlsten
- Centre for Bone and Arthritis Research, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Andrée Krust
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (Centre National de la Recherche Scientifique UMR7104; National de la Sante et de la Recherche Medicale U596; ULP, Collège de France), Illkirch, Strasbourg, France
| | - Pierre Chambon
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (Centre National de la Recherche Scientifique UMR7104; National de la Sante et de la Recherche Medicale U596; ULP, Collège de France), Illkirch, Strasbourg, France
| | - Klara Sjögren
- Centre for Bone and Arthritis Research, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Marie K Lagerquist
- Centre for Bone and Arthritis Research, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Sara H Windahl
- 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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Macari S, Ajay Sharma L, Wyatt A, Knowles P, Szawka R, Garlet G, Grattan D, Dias G, Silva T. Osteoprotective Effects of Estrogen in the Maxillary Bone Depend on ERα. J Dent Res 2016; 95:689-96. [DOI: 10.1177/0022034516633154] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Estrogen deficiency results in disruption of maxillary alveolar bone microarchitecture. Most of the actions of estrogen in long bones occur via estrogen receptor α (ERα). However, the function of ERα in the maxillary bone has not been defined. We aimed to investigate the role and underlying mechanisms of ERα in the physiological and mechanically induced alveolar bone remodeling in female and male mice. Wild-type (WT) and ERα−/− (ERKOα) mice were subjected to mechanically stimulated bone remodeling by inducing orthodontic tooth movement (OTM). The maxillary bone was analyzed using histomorphometric analysis, micro–computed tomography, quantitative polymerase chain reaction, and energy-dispersive spectroscopy. Bone marrow cells (BMCs) from WT and ERKOα mice were tested for their capacity to differentiate into osteoblasts and osteoclasts. Both male and female ERKOα mice exhibited marked reduction of alveolar bone mass and increased OTM. This response was associated with an increased number of osteoclasts and reduced number of apoptotic cells and osteoblasts in the periodontium and alveolar bone. Consistently, ERKOα mice exhibited lower levels of calcium in bone and increased expression of IL-33 (interleukin-33), TNF-α (tumor necrosis factor α), and IL-1β (interleukin-1β) and decreased expression of dentin matrix acidic phosphoprotein and alkaline phosphatase in periodontal tissues. Moreover, the differentiation of osteoclasts and osteoblasts in vitro was significantly higher in BMCs obtained from ERKOα. ERα is required to maintain the microarchitecture of maxillary alveolar bone. This process is linked to bone cell differentiation and apoptosis, as well as local production of inflammatory molecules such as IL-33, TNF-α, and IL-1β.
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Affiliation(s)
- S. Macari
- Department of Oral Pathology and Surgery, Faculty of Dentistry, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - L. Ajay Sharma
- Department of Anatomy, University of Otago, Dunedin, New Zealand
| | - A. Wyatt
- Department of Anatomy, University of Otago, Dunedin, New Zealand
| | - P. Knowles
- Department of Anatomy, University of Otago, Dunedin, New Zealand
| | - R.E. Szawka
- Department of Physiology and Biophysics, Biological Science Institute, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - G.P. Garlet
- Department of Biological Sciences, School of Dentistry of Bauru, São Paulo University, Bauru, SP, Brazil
| | - D.R. Grattan
- Department of Anatomy, University of Otago, Dunedin, New Zealand
| | - G.J. Dias
- Department of Anatomy, University of Otago, Dunedin, New Zealand
| | - T.A. Silva
- Department of Oral Pathology and Surgery, Faculty of Dentistry, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
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Lee SH, Oh KN, Han Y, Choi YH, Lee KY. Estrogen Receptor α Regulates Dlx3-Mediated Osteoblast Differentiation. Mol Cells 2016; 39:156-62. [PMID: 26674964 PMCID: PMC4757804 DOI: 10.14348/molcells.2016.2291] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2015] [Revised: 10/31/2015] [Accepted: 11/03/2015] [Indexed: 01/01/2023] Open
Abstract
Estrogen receptor α (ER-α), which is involved in bone metabolism and breast cancer, has been shown to have transcriptional targets. Dlx3 is essential for the skeletal development and plays an important role in osteoblast differentiation. Various osteogenic stimulators and transcription factors can induce the protein expression of Dlx3. However, the regulatory function of ER-α in the Dlx3 mediated osteogenic process remains unknown. Therefore, we investigated the regulation of Dlx3 and found that ER-α is a positive regulator of Dlx3 transcription in BMP2-induced osteoblast differentiation. We also found that ER-α interacts with Dlx3 and increases its transcriptional activity and DNA binding affinity. Furthermore, we demonstrated that the regulation of Dlx3 activity by ER-α is independent of the ligand (estradiol) binding domain. These results indicate that Dlx3 is a novel target of ER-α, and that ER-α regulates the osteoblast differentiation through modulation of Dlx3 expression and/or interaction with Dlx3.
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Affiliation(s)
- Sung Ho Lee
- College of Pharmacy and Research Institute of Drug Development, Chonnam National University, Gwangju 500-757,
Korea
| | - Kyo-Nyeo Oh
- College of Pharmacy and Research Institute of Drug Development, Chonnam National University, Gwangju 500-757,
Korea
| | - Younho Han
- College of Pharmacy and Research Institute of Drug Development, Chonnam National University, Gwangju 500-757,
Korea
| | - You Hee Choi
- College of Pharmacy and Research Institute of Drug Development, Chonnam National University, Gwangju 500-757,
Korea
| | - Kwang-Youl Lee
- College of Pharmacy and Research Institute of Drug Development, Chonnam National University, Gwangju 500-757,
Korea
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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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Wnt16 Is Associated with Age-Related Bone Loss and Estrogen Withdrawal in Murine Bone. PLoS One 2015; 10:e0140260. [PMID: 26451596 PMCID: PMC4599960 DOI: 10.1371/journal.pone.0140260] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2015] [Accepted: 08/28/2015] [Indexed: 11/19/2022] Open
Abstract
Genome Wide Association Studies suggest that Wnt16 is an important contributor to the mechanisms controlling bone mineral density, cortical thickness, bone strength and ultimately fracture risk. Wnt16 acts on osteoblasts and osteoclasts and, in cortical bone, is predominantly derived from osteoblasts. This led us to hypothesize that low bone mass would be associated with low levels of Wnt16 expression and that Wnt16 expression would be increased by anabolic factors, including mechanical loading. We therefore investigated Wnt16 expression in the context of ageing, mechanical loading and unloading, estrogen deficiency and replacement, and estrogen receptor α (ERα) depletion. Quantitative real time PCR showed that Wnt16 mRNA expression was lower in cortical bone and marrow of aged compared to young female mice. Neither increased nor decreased (by disuse) mechanical loading altered Wnt16 expression in young female mice, although Wnt16 expression was decreased following ovariectomy. Both 17β-estradiol and the Selective Estrogen Receptor Modulator Tamoxifen increased Wnt16 expression relative to ovariectomy. Wnt16 and ERβ expression were increased in female ERα-/- mice when compared to Wild Type. We also addressed potential effects of gender on Wnt16 expression and while the expression was lower in the cortical bone of aged males as in females, it was higher in male bone marrow of aged mice compared to young. In the kidney, which we used as a non-bone reference tissue, Wnt16 expression was unaffected by age in either males or females. In summary, age, and its associated bone loss, is associated with low levels of Wnt16 expression whereas bone loss associated with disuse has no effect on Wnt16 expression. In the artificially loaded mouse tibia we observed no loading-related up-regulation of Wnt16 expression but provide evidence that its expression is influenced by estrogen receptor signaling. These findings suggest that while Wnt16 is not an obligatory contributor to regulation of bone mass per se, it potentially plays a role in influencing pathways associated with regulation of bone mass during ageing and estrogen withdrawal.
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Chuang SC, Chen CH, Fu YC, Tai IC, Li CJ, Chang LF, Ho ML, Chang JK. Estrogen receptor mediates simvastatin-stimulated osteogenic effects in bone marrow mesenchymal stem cells. Biochem Pharmacol 2015; 98:453-64. [PMID: 26410676 DOI: 10.1016/j.bcp.2015.09.018] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2015] [Accepted: 09/22/2015] [Indexed: 11/18/2022]
Abstract
Simvastatin, an HMG-CoA reductase inhibitor, is known to promote osteogenic differentiation. However, the mechanism underlying simvastatin-induced osteogenesis is not well understood. In this study, we hypothesize that the estrogen receptor (ER) mediates simvastatin-induced osteogenic differentiation. ER antagonists and siRNA were used to determine the involvement of the ER in simvastatin-induced osteogenesis in mouse bone marrow mesenchymal stem cells (D1 cells). Osteogenesis was evaluated by mRNA expression, protein level/activity of osteogenic markers, and mineralization. The estrogen response element (ERE) promoter activity and the ER-simvastatin binding affinity were examined. Our results showed that the simvastatin-induced osteogenic effects were decreased by treatment with ERα antagonists and ERα siRNA but not by an antagonist specific for the G protein-coupled estrogen receptor (GPER-1). The simvastatin-induced osteogenic effects were further increased by E2 treatment and were reversed by ERα antagonists or siRNA treatment. Luciferase reporter gene assays demonstrated that simvastatin increase ERα-dependent transcriptional activity that was suppressed by ERα antagonists. Furthermore, the ERα-simvastatin binding assay showed that IC50 value of simvastatin is 7.85 μM and that of E2 is 32.8 nM, indicating that simvastatin is a weak ligand for ERα. These results suggest that simvastatin-stimulated osteogenesis is mediated by ERα but not GPER-1. Moreover, this is the first report to demonstrate that simvastatin acts as an ERα ligand and a co-activator to enhance ERα-dependent transcriptional activity and thus promotes osteogenesis. These results indicate that simvastatin-induced osteogenesis is mediated via an ERα-dependent pathway.
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Affiliation(s)
- Shu-Chun Chuang
- Orthopedic Research Center, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Chung-Hwan Chen
- Orthopedic Research Center, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan; Department of Orthopedics, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan; Department of Orthopedics, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan; Department of Orthopedics, Kaohsiung Municipal Ta-Tung Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Yin-Chin Fu
- Orthopedic Research Center, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan; Department of Orthopedics, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan; Department of Orthopedics, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan; Department of Orthopedics, Kaohsiung Municipal Hsiao-Kang Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - I-Chun Tai
- Orthopedic Research Center, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan; Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan; Department of Physiology, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Ching-Ju Li
- Orthopedic Research Center, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Li-Fu Chang
- Orthopedic Research Center, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Mei-Ling Ho
- Orthopedic Research Center, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan; Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan; Department of Physiology, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan; Department of Marine Biotechnology and Resources, National Sun Yat-sen University, Kaohsiung, Taiwan.
| | - Je-Ken Chang
- Orthopedic Research Center, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan; Department of Orthopedics, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan; Department of Orthopedics, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan; Department of Orthopedics, Kaohsiung Municipal Ta-Tung Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan.
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