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Cavalcanti de Araújo PH, Cezine MER, Vulczak A, Vieira LC, Matsuo FS, Remoto JM, Santos ADR, Miyabara EH, Alberici LC, Osako MK. RANKL signaling drives skeletal muscle into the oxidative profile. J Bone Miner Res 2024; 39:753-764. [PMID: 38619281 DOI: 10.1093/jbmr/zjae058] [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: 03/28/2023] [Revised: 03/13/2024] [Accepted: 04/08/2024] [Indexed: 04/16/2024]
Abstract
The bone-muscle unit refers to the reciprocal regulation between bone and muscle by mechanical interaction and tissue communication via soluble factors. The RANKL stimulation induces mitochondrial biogenesis and increases the oxidative capacity in osteoclasts and adipocytes. RANKL may bind to the membrane bound RANK or to osteoprotegerin (OPG), a decoy receptor that inhibits RANK-RANKL activation. RANK is highly expressed in skeletal muscle, but the contribution of RANKL to healthy skeletal muscle fiber remains elusive. Here we show that RANKL stimulation in C2C12-derived myotubes induced activation of mitochondrial biogenesis pathways as detected by RNA-seq and western blot. RANKL expanded the mitochondrial reticulum, as shown by mitochondrial DNA quantification and MitoTracker staining, and boosted the spare respiratory capacity. Using MEK and MAPK inhibitors, we found that RANKL signals via ERK and p38 to induce mitochondrial biogenesis. The soleus from OPG-/- and OPG+/- mice showed higher respiratory rates compared to C57BL6/J WT mice, which correlates with high serum RANKL levels. RANKL infusion using a mini-osmotic pump in WT mice increased the number of mitochondria, boosted the respiratory rate, increased succinate dehydrogenase activity in skeletal muscle, and improved the fatigue resistance of gastrocnemius. Therefore, our findings reveal a new role of RANKL as an osteokine-like protein that impacts muscle fiber metabolism.
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Affiliation(s)
- Paulo Henrique Cavalcanti de Araújo
- Laboratory of Cell and Tissue Biology, Department of Cell and Molecular Biology and Pathogenic Bioagents, Ribeirao Preto Medical School, University of São Paulo, Ribeirao Preto, São Paulo 14049-900, Brazil
| | - Maria Eduarda Ramos Cezine
- Laboratory of Cell and Tissue Biology, Department of Cell and Molecular Biology and Pathogenic Bioagents, Ribeirao Preto Medical School, University of São Paulo, Ribeirao Preto, São Paulo 14049-900, Brazil
| | - Anderson Vulczak
- Department of Biomolecular Sciences, Faculty of Pharmaceutical Sciences of Ribeirao Preto, University of São Paulo, Ribeirao Preto, São Paulo 14040-903, Brazil
| | - Luiz Carlos Vieira
- Laboratory of Cell and Tissue Biology, Department of Cell and Molecular Biology and Pathogenic Bioagents, Ribeirao Preto Medical School, University of São Paulo, Ribeirao Preto, São Paulo 14049-900, Brazil
| | - Flávia Sayuri Matsuo
- Laboratory of Cell and Tissue Biology, Department of Cell and Molecular Biology and Pathogenic Bioagents, Ribeirao Preto Medical School, University of São Paulo, Ribeirao Preto, São Paulo 14049-900, Brazil
| | - Júlia Maranghetti Remoto
- Laboratory of Cell and Tissue Biology, Department of Cell and Molecular Biology and Pathogenic Bioagents, Ribeirao Preto Medical School, University of São Paulo, Ribeirao Preto, São Paulo 14049-900, Brazil
| | - Audrei Dos Reis Santos
- Department of Anatomy, Institute of Biomedical Sciences, University of São Paulo, São Paulo 05508-000, Brazil
| | - Elen Haruka Miyabara
- Department of Anatomy, Institute of Biomedical Sciences, University of São Paulo, São Paulo 05508-000, Brazil
| | - Luciane Carla Alberici
- Department of Biomolecular Sciences, Faculty of Pharmaceutical Sciences of Ribeirao Preto, University of São Paulo, Ribeirao Preto, São Paulo 14040-903, Brazil
| | - Mariana Kiomy Osako
- Laboratory of Cell and Tissue Biology, Department of Cell and Molecular Biology and Pathogenic Bioagents, Ribeirao Preto Medical School, University of São Paulo, Ribeirao Preto, São Paulo 14049-900, Brazil
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Ono S, Tsuji N, Sakamoto T, Oguchi S, Nakamura T, Hoshi K, Hikita A. Inhibition of cysteine protease disturbs the topological relationship between bone resorption and formation in vitro. J Bone Miner Metab 2024; 42:166-184. [PMID: 38376670 PMCID: PMC10982105 DOI: 10.1007/s00774-023-01489-w] [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: 10/06/2023] [Accepted: 11/17/2023] [Indexed: 02/21/2024]
Abstract
INTRODUCTION Osteoporosis is a global health issue. Bisphosphonates that are commonly used to treat osteoporosis suppress both bone resorption and subsequent bone formation. Inhibition of cathepsin K, a cysteine proteinase secreted by osteoclasts, was reported to suppress bone resorption while preserving or increasing bone formation. Analyses of the different effects of antiresorptive reagents such as bisphosphonates and cysteine proteinase inhibitors will contribute to the understanding of the mechanisms underlying bone remodeling. MATERIALS AND METHODS Our team has developed an in vitro system in which bone remodeling can be temporally observed at the cellular level by 2-photon microscopy. We used this system in the present study to examine the effects of the cysteine proteinase inhibitor E-64 and those of zoledronic acid on bone remodeling. RESULTS In the control group, the amount of the reduction and the increase in the matrix were correlated in each region of interest, indicating the topological and quantitative coordination of bone resorption and formation. Parameters for osteoblasts, osteoclasts, and matrix resorption/formation were also correlated. E-64 disrupted the correlation between resorption and formation by potentially inhibiting the emergence of spherical osteoblasts, which are speculated to be reversal cells in the resorption sites. CONCLUSION These new findings help clarify coupling mechanisms and will contribute to the development of new drugs for osteoporosis.
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Affiliation(s)
- Sayaka Ono
- Department of Sensory and Motor System Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo, 113-8655, Japan
| | - Naoki Tsuji
- Department of Tissue Engineering, The University of Tokyo Hospital, Tokyo, 113-8655, Japan
| | - Tomoaki Sakamoto
- Department of Tissue Engineering, The University of Tokyo Hospital, Tokyo, 113-8655, Japan
| | - Shuya Oguchi
- Department of Oral-Maxillofacial Surgery, and Orthodontics, The University of Tokyo Hospital, Tokyo, 113-8655, Japan
| | - Takashi Nakamura
- Department of Biochemistry, Tokyo Dental College, Tokyo, 101-0061, Japan
| | - Kazuto Hoshi
- Department of Sensory and Motor System Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo, 113-8655, Japan
- Department of Tissue Engineering, The University of Tokyo Hospital, Tokyo, 113-8655, Japan
- Department of Oral-Maxillofacial Surgery, and Orthodontics, The University of Tokyo Hospital, Tokyo, 113-8655, Japan
| | - Atsuhiko Hikita
- Department of Tissue Engineering, The University of Tokyo Hospital, Tokyo, 113-8655, Japan.
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Naeem A, Noureen N, Al-Naemi SK, Al-Emadi JA, Khan MJ. Computational design of anti-cancer peptides tailored to target specific tumor markers. BMC Chem 2024; 18:39. [PMID: 38388460 PMCID: PMC10882887 DOI: 10.1186/s13065-024-01143-0] [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: 11/28/2023] [Accepted: 02/13/2024] [Indexed: 02/24/2024] Open
Abstract
Anti-cancer peptides (ACPs) are short peptides known for their ability to inhibit tumor cell proliferation, migration, and the formation of tumor blood vessels. In this study, we designed ACPs to target receptors often overexpressed in cancer using a systematic in silico approach. Three target receptors (CXCR1, DcR3, and OPG) were selected for their significant roles in cancer pathogenesis and tumor cell proliferation. Our peptide design strategy involved identifying interacting residues (IR) of these receptors, with their natural ligands serving as a reference for designing peptides specific to each receptor. The natural ligands of these receptors, including IL8 for CXCR1, TL1A for DcR3, and RANKL for OPG, were identified from the literature. Using the identified interacting residues (IR), we generated a peptide library through simple permutation and predicted the structure of each peptide. All peptides were analyzed using the web-based prediction server for Anticancer peptides, AntiCP. Docking simulations were then conducted to analyze the binding efficiencies of peptides with their respective target receptors, using VEGA ZZ and Chimera for interaction analysis. Our analysis identified HPKFIKELR as the interacting residues (IR) of CXCR-IL8. For DcR3, we utilized three domains from TL1A (TDSYPEP, TKEDKTF, LGLAFTK) as templates, along with two regions (SIKIPSS and PDQDATYP) from RANKL, to generate a library of peptide analogs. Subsequently, peptides for each receptor were shortlisted based on their predicted anticancer properties as determined by AntiCP and were subjected to docking analysis. After docking, peptides that exhibited the least binding energy were further analyzed for their detailed interaction with their respective receptors. Among these, peptides C9 (HPKFELY) and C7 (HPKFEWL) for CXCR1, peptides D6 (ADSYPQP) and D18 (AFSYPFP) for DcR3, and peptides P19 (PDTYPQDP) and p16 (PDQDATYP) for OPG, demonstrated the highest affinity and stronger interactions compared to the other peptides. Although in silico predictions indicated a favorable binding affinity of the designed peptides with target receptors, further experimental validation is essential to confirm their binding affinity, stability and pharmacokinetic characteristics.
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Affiliation(s)
- Aisha Naeem
- QU Health, Qatar University, P.O. Box 2713, Doha, Qatar.
| | - Nighat Noureen
- Cancer Center and Department of Pediatrics, School of Medicine, Texas Tech University Health Sciences Center School of Medicine, Lubbock, TX, 79430, USA.
| | | | | | - Muhammad Jawad Khan
- Department of Biosciences, COMSATS University Islamabad, Islamabad, 45550, Pakistan
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Takito J, Nonaka N. Osteoclasts at Bone Remodeling: Order from Order. Results Probl Cell Differ 2024; 71:227-256. [PMID: 37996681 DOI: 10.1007/978-3-031-37936-9_12] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2023]
Abstract
Osteoclasts are multinucleated bone-resorbing cells derived from the monocyte/macrophage lineage. The macrophage colony-stimulating factor/receptor activator of nuclear factor κB ligand (M-CSF/RANKL) signaling network governs the differentiation of precursor cells into fusion-competent mononucleated cells. Repetitive fusion of fusion-competent cells produces multinucleated osteoclasts. Osteoclasts are believed to die via apoptosis after bone resorption. However, recent studies have found that osteoclastogenesis in vivo proceeds by replacing the old nucleus of existing osteoclasts with a single newly differentiated mononucleated cell. Thus, the formation of new osteoclasts is minimal. Furthermore, the sizes of osteoclasts can change via cell fusion and fission in response to external conditions. On the other hand, osteoclastogenesis in vitro involves various levels of heterogeneity, including osteoclast precursors, mode of fusion, and properties of the differentiated osteoclasts. To better understand the origin of these heterogeneities and the plasticity of osteoclasts, we examine several processes of osteoclastogenesis in this review. Candidate mechanisms that create heterogeneity involve asymmetric cell division, osteoclast niche, self-organization, and mode of fusion and fission. Elucidation of the plasticity or fluctuation of the M-CSF/RANKL network should be an important topic for future researches.
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Affiliation(s)
- Jiro Takito
- Department of Oral Anatomy and Developmental Biology, School of Dentistry, Showa University, Tokyo, Japan.
| | - Naoko Nonaka
- Department of Oral Anatomy and Developmental Biology, School of Dentistry, Showa University, Tokyo, Japan
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The role of hypertrophic chondrocytes in regulation of the cartilage-to-bone transition in fracture healing. Bone Rep 2022; 17:101616. [PMID: 36105852 PMCID: PMC9465425 DOI: 10.1016/j.bonr.2022.101616] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Revised: 05/05/2022] [Accepted: 06/07/2022] [Indexed: 11/23/2022] Open
Abstract
Endochondral bone formation is an important pathway in fracture healing, involving the formation of a cartilaginous soft callus and the process of cartilage-to-bone transition. Failure or delay in the cartilage-to-bone transition causes an impaired bony union such as nonunion or delayed union. During the healing process, multiple types of cells including chondrocytes, osteoprogenitors, osteoblasts, and endothelial cells coexist in the callus, and inevitably crosstalk with each other. Hypertrophic chondrocytes located between soft cartilaginous callus and bony hard callus mediate the crosstalk regulating cell-matrix degradation, vascularization, osteoclast recruitment, and osteoblast differentiation in autocrine and paracrine manners. Furthermore, hypertrophic chondrocytes can become osteoprogenitors and osteoblasts, and directly contribute to woven bone formation. In this review, we focus on the roles of hypertrophic chondrocytes in fracture healing and dissect the intermingled crosstalk in fracture callus during the cartilage-to-bone transition.
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Bai S, Yang Y, Ma X, Liao X, Wang R, Zhang L, Li S, Luo X, Lu L. Dietary calcium requirements of broilers fed a conventional corn-soybean meal diet from 1 to 21 days of age. J Anim Sci Biotechnol 2022; 13:11. [PMID: 35109932 PMCID: PMC8812165 DOI: 10.1186/s40104-021-00652-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Accepted: 11/16/2021] [Indexed: 11/13/2022] Open
Abstract
Background The current calcium (Ca) recommendation for broilers is primarily based on studies conducted more than 30 years ago with birds of markedly different productive potentials from those which exist today. And the response indicators in these studies are mainly growth performance and bone ash percentage. Therefore, the present study was carried out to investigate the effect of dietary Ca level on growth performance, serum parameters, bone characteristics and Ca metabolism-related gene expressions, so as to estimate dietary Ca requirements of broilers fed a conventional corn-soybean meal diet from 1 to 21 days of age. Methods A total of 420 1-day-old Arbor Acres male broilers were randomly assigned to 1 of 7 treatments with 6 replicates (10 birds per cage) and fed the corn-soybean meal diets containing 0.60%, 0.70%, 0.80%, 0.90%, 1.00%, 1.10% or 1.20% Ca for 21 days. Each diet contained the constant non-phytate phosphorus content of about 0.39%. Results The average daily gain decreased linearly (P < 0.001) as dietary Ca level increased. The serum and tibia alkaline phosphatase (ALP) activities, tibia bone mineral density (BMD), middle toe BMD, tibia ash percentage, tibia breaking strength, and tibia ALP protein expression level were affected (P < 0.05) by dietary Ca level, and showed significant quadratic responses (P < 0.02) to dietary Ca levels. The estimates of dietary Ca requirements were 0.80 to 1.00% based on the best fitted broken-line or quadratic models (P < 0.03) of the above serum and bone parameters, respectively. Conclusions The results from the present study indicate that the Ca requirements would be about 0.60% to obtain the best growth rate, and 1.00% to meet all of the Ca metabolisms and bone development of broilers fed a conventional corn-soybean meal diet from 1 to 21 days of age.
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Affiliation(s)
- Shiping Bai
- Mineral Nutrition Research Division, State Key Laboratory of Animal Nutrition, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, 100193, China.,Poultry Mineral Nutrition Laboratory, College of Animal Science and Technology, Yangzhou University, Yangzhou, 225000, China.,Institute of Animal Nutrition, Sichuan Agricultural University, Chengdu, 611130, Sichuan, China
| | - Yunfeng Yang
- Mineral Nutrition Research Division, State Key Laboratory of Animal Nutrition, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Xuelian Ma
- Mineral Nutrition Research Division, State Key Laboratory of Animal Nutrition, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Xiudong Liao
- Mineral Nutrition Research Division, State Key Laboratory of Animal Nutrition, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Runlian Wang
- Department of Animal Science, Guangdong Ocean University, Zhanjiang, 524088, China
| | - Liyang Zhang
- Mineral Nutrition Research Division, State Key Laboratory of Animal Nutrition, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Sufen Li
- Department of Animal Science, Hebei Normal University of Science and Technology, Qinhuangdao, 066004, China
| | - Xugang Luo
- Poultry Mineral Nutrition Laboratory, College of Animal Science and Technology, Yangzhou University, Yangzhou, 225000, China.
| | - Lin Lu
- Mineral Nutrition Research Division, State Key Laboratory of Animal Nutrition, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, 100193, China.
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Naik AA, Sivaramakrishnan V. Systems analysis of steroid induced osteonecrosis shows role for heme and vitamin D in pathogenesis. GENE REPORTS 2021. [DOI: 10.1016/j.genrep.2021.101383] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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8
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Downregulated fat mass and obesity-associated protein inhibits bone resorption and osteoclastogenesis by nuclear factor-kappa B inactivation. Cell Signal 2021; 87:110137. [PMID: 34469786 DOI: 10.1016/j.cellsig.2021.110137] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Revised: 08/17/2021] [Accepted: 08/24/2021] [Indexed: 11/20/2022]
Abstract
During osteoporosis, fat mass and obesity-associated protein (FTO) promotes the shift of bone marrow mesenchymal stem cells to adipocytes and represses osteoblast activity. However, the role and mechanisms of FTO on osteoclast formation and bone resorption remain unknown. In this study, we investigated the effect of FTO on RAW264.7 cells and bone marrow monocytes (BMMs)-derived osteoclasts in vitro and observed the influence of FTO on ovariectomized (OVX) mice model to mimic postmenopausal osteoporosis in vivo. Results found that FTO was up-regulated in BMMs from OVX mice. Double immunofluorescence assay showed co-localization of FTO with tartrate-resistant acid phosphatase (TRAP) in femurs of OVX mice. FTO overexpression enhanced TRAP-positive osteoclasts and F-actin ring formation in RAW264.7 cells upon RANKL stimulation. The expression of osteoclast differentiation-related genes, including nuclear factor of activated T cells c1 (NFATc1) and c-FOS, was upregulated in BMMs and RAW264.7 cells after FTO overexpression. FTO overexpression induced the phosphorylation and nuclear translocation of factor-kappa B (NF-κB) p65 in BMMs and RAW264.7 cells exposed to RANKL. ChIP and dual-luciferase assays revealed that FTO overexpression contributed to RANKL-induced binding of NF-κB to NFATc1 promoter. Rescue experiments suggested that FTO overexpression-mediated osteoclast differentiation was suppressed after intervention with a NF-κB inhibitor pyrrolidine dithiocarbamate. Further in vivo evidence revealed that FTO knockdown increased bone trabecula and bone mineral density, inhibited bone resorption and osteoclastogenesis in osteoporotic mice. Collectively, our research demonstrates that downregulated FTO inhibits bone resorption and osteoclastogenesis through NF-κB inactivation, which provides a novel reference for osteoporosis treatment.
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Wei H, Pan L, Li C, Zhao P, Li J, Zhang R, Bao J. Dietary Soybean Oil Supplementation Affects Keel Bone Characters and Daily Feed Intake but Not Egg Production and Quality in Laying Hens Housed in Furnished Cages. Front Vet Sci 2021; 8:657585. [PMID: 33816591 PMCID: PMC8017272 DOI: 10.3389/fvets.2021.657585] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2021] [Accepted: 03/03/2021] [Indexed: 11/13/2022] Open
Abstract
To evaluate dietary soybean oil supplementation on production performance, egg quality, and keel bone health in laying hens. Two hundred and four laying hens at 20 weeks of age (WOA) were distributed into 12 cages containing 17 birds each. Birds were either fed a commercial diet (control group, CON) or a diet supplemented with 3% of soybean oil (SO group). Experiments lasted 17 weeks. Body weight, daily feed intake, production performance and egg quality were measured at 25, 29, 33, and 37 WOA. Birds were subsequently assessed for keel bone status by palpation, and keel was excised to measure bone length, microstructure, bone mineral density (BMD), elements contents, and the expression of osteoprotegerin (OPG), receptor activator of nuclear factor kappa-B ligand (RANKL), collagen type II alpha 1 (COL2α1), periostin (POSTN), and sclerostin (SOST). The results showed that dietary SO supplementation did not affect production performance and egg quality (P > 0.05), but improved body weight of hens at 29 and 37 WOA (P < 0.05), and decreased daily feed intake at 33 and 37 WOA (P < 0.05). Incidence of keel bone damage (especially fracture) was higher in hens of SO group. Keel bone length in birds of SO group was significantly decreased compared to CON (P < 0.05). Keel bone of supplemented hens showed increased trabecular separation at 29 WOA and higher levels of V, Mn, Fe, Se, and Ba at 33 WOA (P < 0.05). Moreover, decreased BMD, trabecular number and thickness were observed in keel bone of laying hens receiving supplementation at 29 and 37 WOA (P < 0.05); decreased levels of Li, Ca, Hg, and TI at 33 WOA and trabecular thickness at 37 WOA (P < 0.05) were also identified. mRNA levels of SOST and RANKL and the ratio of RANKL/OPG mRNA levels were increased in birds fed a SO-supplemented diet (P < 0.05); COL2α1, OPG, and POSTN were downregulated at all sampling points (P < 0.05). Taken together, results indicate that feeding laying hens a diet supplemented with soybean oil can decrease daily feed intake and impair keel bone health but not influence production performance and egg quality.
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Affiliation(s)
- Haidong Wei
- College of Animal Science and Technology, Northeast Agricultural University, Harbin, China
| | - Lei Pan
- College of Animal Science and Technology, Northeast Agricultural University, Harbin, China
| | - Chun Li
- College of Life Science, Northeast Agricultural University, Harbin, China
| | - Peng Zhao
- College of Animal Science and Technology, Northeast Agricultural University, Harbin, China
| | - Jianhong Li
- College of Life Science, Northeast Agricultural University, Harbin, China
| | - Runxiang Zhang
- College of Animal Science and Technology, Northeast Agricultural University, Harbin, China.,Key Laboratory of Chicken Genetics and Breeding, Ministry of Agriculture and Rural Affairs, Harbin, China
| | - Jun Bao
- College of Animal Science and Technology, Northeast Agricultural University, Harbin, China.,Key Laboratory of Chicken Genetics and Breeding, Ministry of Agriculture and Rural Affairs, Harbin, China
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Zhang Y, Luo G, Yu X. Cellular Communication in Bone Homeostasis and the Related Anti-osteoporotic Drug Development. Curr Med Chem 2020; 27:1151-1169. [PMID: 30068268 DOI: 10.2174/0929867325666180801145614] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Revised: 06/28/2018] [Accepted: 07/19/2018] [Indexed: 02/08/2023]
Abstract
Background:Intercellular crosstalk among osteoblast, osteoclast, osteocyte and chondrocyte is involved in the precise control of bone homeostasis. Disruption of this cellular and molecular signaling would lead to metabolic bone diseases such as osteoporosis. Currently a number of anti-osteoporosis interventions are restricted by side effects, complications and long-term intolerance. This review aims to summarize the bone cellular communication involved in bone remodeling and its usage to develop new drugs for osteoporosis. Methods:We searched PubMed for publications from 1 January 1980 to 1 January 2018 to identify relevant and latest literatures, evaluation and prospect of osteoporosis medication were summarized. Detailed search terms were 'osteoporosis', 'osteocyte', 'osteoblast', 'osteoclast', 'bone remodeling', 'chondrocyte', 'osteoporosis treatment', 'osteoporosis therapy', 'bisphosphonates', 'denosumab', 'Selective Estrogen Receptor Modulator (SERM)', 'PTH', 'romosozumab', 'dkk-1 antagonist', 'strontium ranelate'. Results:A total of 170 papers were included in the review. About 80 papers described bone cell interactions involved in bone remodeling. The remaining papers were focused on the novel advanced and new horizons in osteoporosis therapies. Conclusion:There exists a complex signal network among bone cells involved in bone remodeling. The disorder of cell-cell communications may be the underlying mechanism of osteoporosis. Current anti-osteoporosis therapies are effective but accompanied by certain drawbacks simultaneously. Restoring the abnormal signal network and individualized therapy are critical for ideal drug development.
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Affiliation(s)
- Yi Zhang
- Laboratory of Endocrinology and Metabolism, Department of Endocrinology and Metabolism, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Guojing Luo
- Laboratory of Endocrinology and Metabolism, Department of Endocrinology and Metabolism, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Xijie Yu
- Laboratory of Endocrinology and Metabolism, Department of Endocrinology and Metabolism, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu 610041, China
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RANKL/RANK/OPG Pathway: A Mechanism Involved in Exercise-Induced Bone Remodeling. BIOMED RESEARCH INTERNATIONAL 2020; 2020:6910312. [PMID: 32149122 PMCID: PMC7053481 DOI: 10.1155/2020/6910312] [Citation(s) in RCA: 136] [Impact Index Per Article: 34.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/16/2019] [Accepted: 01/06/2020] [Indexed: 12/21/2022]
Abstract
Bones as an alive organ consist of about 70% mineral and 30% organic component. About 200 million people are suffering from osteopenia and osteoporosis around the world. There are multiple ways of protecting bone from endogenous and exogenous risk factors. Planned physical activity is another useful way for protecting bone health. It has been investigated that arranged exercise would effectively regulate bone metabolism. Until now, a number of systems have discovered how exercise could help bone health. Previous studies reported different mechanisms of the effect of exercise on bone health by modulation of bone remodeling. However, the regulation of RANKL/RANK/OPG pathway in exercise and physical performance as one of the most important remodeling systems is not considered comprehensive in previous evidence. Therefore, the aim of this review is to clarify exercise influence on bone modeling and remodeling, with a concentration on its role in regulating RANKL/RANK/OPG pathway.
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Comprehensive assessment of tissue and serum parameters of bone metabolism in a series of orthopaedic patients. PLoS One 2019; 14:e0227133. [PMID: 31881044 PMCID: PMC6934299 DOI: 10.1371/journal.pone.0227133] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Accepted: 12/11/2019] [Indexed: 12/21/2022] Open
Abstract
Bone diseases represent an increasing health burden worldwide, and basic research remains necessary to better understand the complexity of these pathologies and to improve and expand existing prevention and treatment approaches. In the present study, 216 bone samples from the caput femoris and collum femoris of 108 patients with degenerative or dysplastic coxarthrosis, hip fracture, or osteonecrosis were evaluated for the proportion of trabecular bone (TB) and expression of parathyroid hormone (PTH) type 1 receptor (PTH1R), osteoprotegerin (OPG), and receptor activator of nuclear factor kappa-B ligand (RANKL). Serum levels of PTH, OPG, soluble RANKL (sRANKL), alkaline phosphatase (AP), osteocalcin, total procollagen type-1 intact N-terminal propeptide (TP1NP), tartrate-resistant acid phosphatase type 5b (TRAP5b), sclerostin, and C-telopeptide of type-1 collagen (ICTP) were also determined. Age was positively correlated with serum levels of PTH, OPG, and sclerostin but negatively associated with TB and sRANKL. Women exhibited less TB, lower sclerostin and ICTP, and higher TRAP5b. Impaired kidney function was associated with shorter bone decalcification time, less TB, lower sRANKL, and higher serum PTH, OPG, and sclerostin. Furthermore, correlations were observed between bone PTH1R and OPG expression and between serum PTH, OPG, and AP. There were also positive correlations between serum OPG and TP1NP; serum OPG and sclerostin; serum AP, osteocalcin, and TRAP5b; and serum sclerostin and ICTP. Serum OPG was negatively associated with sRANKL. In summary, clear relationships between specific bone metabolism markers were observed, and distinct influences of age, sex, and kidney function, thus underscoring their suitability as diagnostic or prognostic markers.
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Abstract
Bone is a crucial element of the skeletal-locomotor system, but also functions as an immunological organ that harbors hematopoietic stem cells (HSCs) and immune progenitor cells. Additionally, the skeletal and immune systems share a number of regulatory molecules, including cytokines and signaling molecules. Osteoimmunology was created as an interdisciplinary field to explore the shared molecules and interactions between the skeletal and immune systems. In particular, the importance of an inseparable link between the two systems has been highlighted by studies on the pathogenesis of rheumatoid arthritis (RA), in which pathogenic helper T cells induce the progressive destruction of multiple joints through aberrant expression of receptor activator of nuclear factor (NF)-κB ligand (RANKL). The conceptual bridge of osteoimmunology provides not only a novel framework for understanding these biological systems but also a molecular basis for the development of therapeutic approaches for diseases of bone and/or the immune system.
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Affiliation(s)
- Kazuo Okamoto
- Department of Osteoimmunology, Graduate School of Medicine and Faculty of Medicine, The University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Hiroshi Takayanagi
- Department of Immunology, Graduate School of Medicine and Faculty of Medicine, The University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033, Japan
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14
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Hu H, Zhao X, Ma J, Shangguan Y, Pan Z, Chen L, Zhang X, Wang H. Prenatal nicotine exposure retards osteoclastogenesis and endochondral ossification in fetal long bones in rats. Toxicol Lett 2018; 295:249-255. [PMID: 29981921 DOI: 10.1016/j.toxlet.2018.07.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Revised: 06/06/2018] [Accepted: 07/04/2018] [Indexed: 12/21/2022]
Abstract
This study investigated the mechanisms underlying the retarded development of long bone in fetus by prenatal nicotine exposure (PNE) which had been demonstrated by our previous work. Nicotine (2.0 mg/kg.d) or saline was injected subcutaneously into pregnant rats every morning from gestational day (GD) 9 to 20. Fetal femurs or tibias were harvested for analysis on GD 20. We found massive accumulation of hypertrophic chondrocytes and a delayed formation of primary ossification center (POC) in the fetal femur or tibia of rat fetus after PNE, which was accompanied by a decreased amount of osteoclasts in the POC and up-regulated expression of osteoprotegerin (OPG) but by no obvious change in the expression of receptor activator of NF-κB ligand (RANKL). In primary osteoblastic cells, both nicotine (0, 162, 1620, 16,200 ng/ml) and corticosterone (0, 50, 250, 1250 nM) promoted the mRNA expression of OPG but concentration-dependently suppressed that of RANKL. Furthermore, blocking α4β2-nicotinic acetylcholine receptor (α4β2-nAChR) or glucocorticoid receptor rescued the above effects of nicotine and corticosterone, respectively. In conclusion, retarded osteoclastogenesis may contribute to delayed endochondral ossification in long bone in fetal rats with PNE. The adverse effects of PNE may be mediated via the direct effect of nicotine and indirect effect of maternal corticosterone on osteoblastic cells.
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Affiliation(s)
- Hang Hu
- Department of Pharmacology, Basic Medical School of Wuhan University, Hubei Provincial Key Laboratory of Developmentally Originated Disease, Wuhan 430071, China; Department of Physiology, Basic Medical School of Wuhan University, Wuhan 430071, China
| | - Xin Zhao
- Department of Physiology, Basic Medical School of Wuhan University, Wuhan 430071, China
| | - Jing Ma
- Department of Pharmacology, Basic Medical School of Wuhan University, Hubei Provincial Key Laboratory of Developmentally Originated Disease, Wuhan 430071, China; Department of Physiology, Basic Medical School of Wuhan University, Wuhan 430071, China
| | - Yangfan Shangguan
- Department of Pharmacology, Basic Medical School of Wuhan University, Hubei Provincial Key Laboratory of Developmentally Originated Disease, Wuhan 430071, China; Department of Orthopaedic Surgery, Zhongnan Hospital of Wuhan University, Wuhan 430071, China
| | - Zhengqi Pan
- Department of Pharmacology, Basic Medical School of Wuhan University, Hubei Provincial Key Laboratory of Developmentally Originated Disease, Wuhan 430071, China; Department of Orthopaedic Surgery, Zhongnan Hospital of Wuhan University, Wuhan 430071, China
| | - Liaobin Chen
- Department of Orthopaedic Surgery, Zhongnan Hospital of Wuhan University, Wuhan 430071, China
| | - Xianrong Zhang
- Department of Orthopaedics and Traumatology, Nanfang Hospital, Southern Medical University, Guangdong Provincial Key Laboratory of Bone and Cartilage Regenerative Medicine, Nanfang Hospital, Southern Medical University, No.1838 North of Guangzhou Avenue, Guangzhou, 510515, China.
| | - Hui Wang
- Department of Pharmacology, Basic Medical School of Wuhan University, Hubei Provincial Key Laboratory of Developmentally Originated Disease, Wuhan 430071, China.
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15
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Zhou Y, Wang T, Hamilton JL, Chen D. Wnt/β-catenin Signaling in Osteoarthritis and in Other Forms of Arthritis. Curr Rheumatol Rep 2018; 19:53. [PMID: 28752488 DOI: 10.1007/s11926-017-0679-z] [Citation(s) in RCA: 142] [Impact Index Per Article: 23.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
PURPOSE OF REVIEW Arthritis defines a large group of diseases primarily affecting the joint. It is the leading cause of pain and disability in adults. Osteoarthritis (OA) affecting the knee or hip is the most common form among over 100 types of arthritis. Other types of arthritis include erosive hand OA, temporomandibular joint (TMJ) OA, facet joint OA, diffuse idiopathic skeletal hyperostosis (DISH), and spondyloarthritis (SpA). However, the specific molecular signals involved in the development and progression of OA and related forms of arthritis remain largely unknown. The canonical wingless/integrated (Wnt)/β-catenin signaling pathway could play a unique role in the pathogenesis of arthritis. In this review article, we will focus on the molecular mechanisms of Wnt/β-catenin signaling in the pathogenesis of OA and other types of arthritis. RECENT FINDINGS Emerging evidence demonstrates that Wnts and Wnt-related molecules are involved in arthritis development and progression in human genetic studies and in vitro studies. Also, mouse models have been generated to determine the role of Wnt/β-catenin signaling in the pathogenesis of arthritis. Wnt/β-catenin signaling represents a unique signaling pathway regulating arthritis development and progression, and the molecules in this particular pathway may serve as targets for the therapeutic intervention of arthritis. Mediators and downstream effectors of Wnt/β-catenin signaling are increased in OA as well other forms of arthritis, including DISH and SpA. Through extensive investigations, including pre-clinical studies in transgenic mice and translational and human studies, the Wnt/β-catenin signaling pathway has been proven to play roles in bone and joint pathology by directly affecting bone, cartilage, and synovial tissue; further, these pathologies can be reduced through targeting this pathway. Continued investigation into the distinct molecular signaling of the Wnt/β-catenin pathway will provide additional insights toward the therapeutic intervention in arthritis.
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Affiliation(s)
- Yachuan Zhou
- Department of Orthopedic Surgery, Rush University Medical Center, Chicago, IL, 60612, USA.,State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, China
| | - Tingyu Wang
- Department of Pharmacy, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200011, China
| | - John L Hamilton
- Department of Orthopedic Surgery, Rush University Medical Center, Chicago, IL, 60612, USA
| | - Di Chen
- Department of Orthopedic Surgery, Rush University Medical Center, Chicago, IL, 60612, USA.
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16
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Okamoto K, Nakashima T, Shinohara M, Negishi-Koga T, Komatsu N, Terashima A, Sawa S, Nitta T, Takayanagi H. Osteoimmunology: The Conceptual Framework Unifying the Immune and Skeletal Systems. Physiol Rev 2017; 97:1295-1349. [DOI: 10.1152/physrev.00036.2016] [Citation(s) in RCA: 241] [Impact Index Per Article: 34.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2016] [Revised: 03/29/2017] [Accepted: 04/04/2017] [Indexed: 12/13/2022] Open
Abstract
The immune and skeletal systems share a variety of molecules, including cytokines, chemokines, hormones, receptors, and transcription factors. Bone cells interact with immune cells under physiological and pathological conditions. Osteoimmunology was created as a new interdisciplinary field in large part to highlight the shared molecules and reciprocal interactions between the two systems in both heath and disease. Receptor activator of NF-κB ligand (RANKL) plays an essential role not only in the development of immune organs and bones, but also in autoimmune diseases affecting bone, thus effectively comprising the molecule that links the two systems. Here we review the function, gene regulation, and signal transduction of osteoimmune molecules, including RANKL, in the context of osteoclastogenesis as well as multiple other regulatory functions. Osteoimmunology has become indispensable for understanding the pathogenesis of a number of diseases such as rheumatoid arthritis (RA). We review the various osteoimmune pathologies, including the bone destruction in RA, in which pathogenic helper T cell subsets [such as IL-17-expressing helper T (Th17) cells] induce bone erosion through aberrant RANKL expression. We also focus on cellular interactions and the identification of the communication factors in the bone marrow, discussing the contribution of bone cells to the maintenance and regulation of hematopoietic stem and progenitors cells. Thus the time has come for a basic reappraisal of the framework for understanding both the immune and bone systems. The concept of a unified osteoimmune system will be absolutely indispensable for basic and translational approaches to diseases related to bone and/or the immune system.
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Affiliation(s)
- Kazuo Okamoto
- Department of Osteoimmunology, Graduate School of Medicine and Faculty of Medicine, The University of Tokyo, Tokyo, Japan; Department of Cell Signaling, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan; Japan Science and Technology Agency (JST), Precursory Research for Embryonic Science and Technology (PRESTO), Tokyo, Japan; Japan Agency for Medical Research and Development, Core Research for Evolutional Science and Technology (AMED-CREST), Tokyo, Japan
| | - Tomoki Nakashima
- Department of Osteoimmunology, Graduate School of Medicine and Faculty of Medicine, The University of Tokyo, Tokyo, Japan; Department of Cell Signaling, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan; Japan Science and Technology Agency (JST), Precursory Research for Embryonic Science and Technology (PRESTO), Tokyo, Japan; Japan Agency for Medical Research and Development, Core Research for Evolutional Science and Technology (AMED-CREST), Tokyo, Japan
| | - Masahiro Shinohara
- Department of Osteoimmunology, Graduate School of Medicine and Faculty of Medicine, The University of Tokyo, Tokyo, Japan; Department of Cell Signaling, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan; Japan Science and Technology Agency (JST), Precursory Research for Embryonic Science and Technology (PRESTO), Tokyo, Japan; Japan Agency for Medical Research and Development, Core Research for Evolutional Science and Technology (AMED-CREST), Tokyo, Japan
| | - Takako Negishi-Koga
- Department of Osteoimmunology, Graduate School of Medicine and Faculty of Medicine, The University of Tokyo, Tokyo, Japan; Department of Cell Signaling, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan; Japan Science and Technology Agency (JST), Precursory Research for Embryonic Science and Technology (PRESTO), Tokyo, Japan; Japan Agency for Medical Research and Development, Core Research for Evolutional Science and Technology (AMED-CREST), Tokyo, Japan
| | - Noriko Komatsu
- Department of Osteoimmunology, Graduate School of Medicine and Faculty of Medicine, The University of Tokyo, Tokyo, Japan; Department of Cell Signaling, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan; Japan Science and Technology Agency (JST), Precursory Research for Embryonic Science and Technology (PRESTO), Tokyo, Japan; Japan Agency for Medical Research and Development, Core Research for Evolutional Science and Technology (AMED-CREST), Tokyo, Japan
| | - Asuka Terashima
- Department of Osteoimmunology, Graduate School of Medicine and Faculty of Medicine, The University of Tokyo, Tokyo, Japan; Department of Cell Signaling, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan; Japan Science and Technology Agency (JST), Precursory Research for Embryonic Science and Technology (PRESTO), Tokyo, Japan; Japan Agency for Medical Research and Development, Core Research for Evolutional Science and Technology (AMED-CREST), Tokyo, Japan
| | - Shinichiro Sawa
- Department of Osteoimmunology, Graduate School of Medicine and Faculty of Medicine, The University of Tokyo, Tokyo, Japan; Department of Cell Signaling, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan; Japan Science and Technology Agency (JST), Precursory Research for Embryonic Science and Technology (PRESTO), Tokyo, Japan; Japan Agency for Medical Research and Development, Core Research for Evolutional Science and Technology (AMED-CREST), Tokyo, Japan
| | - Takeshi Nitta
- Department of Osteoimmunology, Graduate School of Medicine and Faculty of Medicine, The University of Tokyo, Tokyo, Japan; Department of Cell Signaling, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan; Japan Science and Technology Agency (JST), Precursory Research for Embryonic Science and Technology (PRESTO), Tokyo, Japan; Japan Agency for Medical Research and Development, Core Research for Evolutional Science and Technology (AMED-CREST), Tokyo, Japan
| | - Hiroshi Takayanagi
- Department of Osteoimmunology, Graduate School of Medicine and Faculty of Medicine, The University of Tokyo, Tokyo, Japan; Department of Cell Signaling, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan; Japan Science and Technology Agency (JST), Precursory Research for Embryonic Science and Technology (PRESTO), Tokyo, Japan; Japan Agency for Medical Research and Development, Core Research for Evolutional Science and Technology (AMED-CREST), Tokyo, Japan
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17
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Kauffmann P, Hahn W, Sievers N, Troeltzsch M, Hohloch K, Brockmeyer P, Cordesmeyer R, Schliephake H, Gruber RM. Osteoblast-like cells with different embryologic origins behave differently in increasing zoledronic acid concentrations: a pilot study in pigs. Oral Surg Oral Med Oral Pathol Oral Radiol 2017; 123:20-28. [DOI: 10.1016/j.oooo.2016.08.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2016] [Revised: 07/18/2016] [Accepted: 08/08/2016] [Indexed: 12/18/2022]
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18
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Houben A, Kostanova-Poliakova D, Weissenböck M, Graf J, Teufel S, von der Mark K, Hartmann C. β-catenin activity in late hypertrophic chondrocytes locally orchestrates osteoblastogenesis and osteoclastogenesis. Development 2016; 143:3826-3838. [PMID: 27621061 PMCID: PMC5087647 DOI: 10.1242/dev.137489] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2016] [Accepted: 08/24/2016] [Indexed: 12/21/2022]
Abstract
Trabecular bone formation is the last step in endochondral ossification. This remodeling process of cartilage into bone involves blood vessel invasion and removal of hypertrophic chondrocytes (HTCs) by chondroclasts and osteoclasts. Periosteal- and chondrocyte-derived osteoprogenitors utilize the leftover mineralized HTC matrix as a scaffold for primary spongiosa formation. Here, we show genetically that β-catenin (encoded by Ctnnb1), a key component of the canonical Wnt pathway, orchestrates this remodeling process at multiple levels. Conditional inactivation or stabilization of β-catenin in HTCs by a Col10a1-Cre line locally modulated osteoclastogenesis by altering the Rankl:Opg ratio in HTCs. Lack of β-catenin resulted in a severe decrease of trabecular bone in the embryonic long bones. Gain of β-catenin activity interfered with removal of late HTCs and bone marrow formation, leading to a continuous mineralized hypertrophic core in the embryo and resulting in an osteopetrotic-like phenotype in adult mice. Furthermore, β-catenin activity in late HTCs is required for chondrocyte-derived osteoblastogenesis at the chondro-osseous junction. The latter contributes to the severe trabecular bone phenotype in mutants lacking β-catenin activity in HTCs. Summary: The conditional modulation of β-catenin activity in late hypertrophic chondrocytes locally regulates osteoclast differentiation and the transdifferentiation of chondrocytes into osteoblasts.
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Affiliation(s)
- Astrid Houben
- Institute of Experimental Musculoskeletal Medicine, Medical Faculty of the University of Münster, Domagkstrasse 3, 48149 Münster, Germany
| | | | - Martina Weissenböck
- Research Institute of Molecular Pathology, Dr. Bohr-Gasse 7, A-1030 Vienna, Austria
| | - Julian Graf
- Institute of Experimental Musculoskeletal Medicine, Medical Faculty of the University of Münster, Domagkstrasse 3, 48149 Münster, Germany
| | - Stefan Teufel
- Institute of Experimental Musculoskeletal Medicine, Medical Faculty of the University of Münster, Domagkstrasse 3, 48149 Münster, Germany
| | - Klaus von der Mark
- Dept. of Experimental Medicine I, University of Erlangen-Nürnberg, Glückstrasse 6, 91054 Erlangen, Germany
| | - Christine Hartmann
- Institute of Experimental Musculoskeletal Medicine, Medical Faculty of the University of Münster, Domagkstrasse 3, 48149 Münster, Germany
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19
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Zhang X, Shang-Guan Y, Ma J, Hu H, Wang L, Magdalou J, Chen L, Wang H. Mitogen-inducible gene-6 partly mediates the inhibitory effects of prenatal dexamethasone exposure on endochondral ossification in long bones of fetal rats. Br J Pharmacol 2016; 173:2250-62. [PMID: 27128203 DOI: 10.1111/bph.13506] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2015] [Revised: 04/05/2016] [Accepted: 04/18/2016] [Indexed: 12/29/2022] Open
Abstract
BACKGROUND AND PURPOSE Prenatal exposure to dexamethasone slows down fetal linear growth and bone mineralization but the regulatory mechanism remains unknown. Here we assessed how dexamethasone regulates bone development in the fetus. EXPERIMENTAL APPROACH Dexamethasone (1 mg·kg(-1) ·day(-1) ) was injected subcutaneously every morning in pregnant rats from gestational day (GD)9 to GD20. Fetal femurs and tibias were harvested at GD20 for histological and gene expression analysis. Femurs of 12-week-old female offspring were harvested for microCT (μCT) measurement. Primary chondrocytes were treated with dexamethasone (10, 50, 250 and 1000 nM). KEY RESULTS Prenatal dexamethasone exposure resulted in accumulation of hypertrophic chondrocytes and delayed formation of the primary ossification centre in fetal long bone. The retardation was accompanied by reduced maturation of hypertrophic chondrocytes, decreased osteoclast number and down-regulated expression of osteocalcin and bone sialoprotein in long bone. In addition, the mitogen-inducible gene-6 (Mig6) and osteoprotegerin (OPG) expression were stimulated, and the receptor activator of NF-κB ligand (RANKL) expression was repressed. Moreover, dexamethasone activated OPG and repressed RANKL expression in both primary chondrocytes and primary osteoblasts, and the knockdown of Mig6 abolished the effect of dexamethasone on OPG expression. Further, μCT measurement showed loss of bone mass in femur of 12-week-old offspring with prenatal dexamethasone exposure. CONCLUSIONS AND IMPLICATIONS Prenatal dexamethasone exposure delays endochondral ossification by suppressing chondrocyte maturation and osteoclast differentiation, which may be partly mediated by Mig6 activation in bone. Bone development retardation in the fetus may be associated with reduced bone mass in later life.
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Affiliation(s)
- Xianrong Zhang
- Department of Physiology, School of Basic Medical Sciences, Wuhan University, Wuhan, China.,Hubei Provincial Key Laboratory of Developmentally Originated Disease, Wuhan, China
| | - Yangfan Shang-Guan
- Hubei Provincial Key Laboratory of Developmentally Originated Disease, Wuhan, China.,Department of Orthopedic Surgery, Zhongnan Hospital of Wuhan University, Wuhan, China
| | - Jing Ma
- Department of Physiology, School of Basic Medical Sciences, Wuhan University, Wuhan, China.,Hubei Provincial Key Laboratory of Developmentally Originated Disease, Wuhan, China
| | - Hang Hu
- Hubei Provincial Key Laboratory of Developmentally Originated Disease, Wuhan, China.,Department of Orthopedic Surgery, Zhongnan Hospital of Wuhan University, Wuhan, China
| | - Linlong Wang
- Hubei Provincial Key Laboratory of Developmentally Originated Disease, Wuhan, China.,Department of Orthopedic Surgery, Zhongnan Hospital of Wuhan University, Wuhan, China
| | - Jacques Magdalou
- Faculté de Médicine, UMR 7561 CNRS-NancyUniversité, Vandoeuvre-lès-Nancy, France
| | - Liaobin Chen
- Hubei Provincial Key Laboratory of Developmentally Originated Disease, Wuhan, China.,Department of Orthopedic Surgery, Zhongnan Hospital of Wuhan University, Wuhan, China
| | - Hui Wang
- Department of Pharmacology, School of Basic Medical Sciences, Wuhan University, Wuhan, China.,Hubei Provincial Key Laboratory of Developmentally Originated Disease, Wuhan, China
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20
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The Modulatory Effects of Mesenchymal Stem Cells on Osteoclastogenesis. Stem Cells Int 2015; 2016:1908365. [PMID: 26823668 PMCID: PMC4707367 DOI: 10.1155/2016/1908365] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2015] [Accepted: 09/21/2015] [Indexed: 12/14/2022] Open
Abstract
The effect of mesenchymal stem cells (MSCs) on bone formation has been extensively demonstrated through several in vitro and in vivo studies. However, few studies addressed the effect of MSCs on osteoclastogenesis and bone resorption. Under physiological conditions, MSCs support osteoclastogenesis through producing the main osteoclastogenic cytokines, RANKL and M-CSF. However, during inflammation, MSCs suppress osteoclast formation and activity, partly via secretion of the key anti-osteoclastogenic factor, osteoprotegerin (OPG). In vitro, co-culture of MSCs with osteoclasts in the presence of high concentrations of osteoclast-inducing factors might reflect the in vivo inflammatory pathology and prompt MSCs to exert an osteoclastogenic suppressive effect. MSCs thus seem to have a dual effect, by stimulating or inhibiting osteoclastogenesis, depending on the inflammatory milieu. This effect of MSCs on osteoclast formation seems to mirror the effect of MSCs on other immune cells, and may be exploited for the therapeutic potential of MSCs in bone loss associated inflammatory diseases.
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21
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Balli U, Aydogdu A, Dede FO, Turer CC, Guven B. Gingival Crevicular Fluid Levels of Sclerostin, Osteoprotegerin, and Receptor Activator of Nuclear Factor-κB Ligand in Periodontitis. J Periodontol 2015; 86:1396-404. [DOI: 10.1902/jop.2015.150270] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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22
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Wang B, Jin H, Shu B, Mira RR, Chen D. Chondrocytes-Specific Expression of Osteoprotegerin Modulates Osteoclast Formation in Metaphyseal Bone. Sci Rep 2015; 5:13667. [PMID: 26329493 PMCID: PMC4556963 DOI: 10.1038/srep13667] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2015] [Accepted: 07/21/2015] [Indexed: 12/21/2022] Open
Abstract
Bone marrow stromal cells/osteoblasts were originally thought to be the major player in regulating osteoclast differentiation through expressing RANKL/OPG cytokines. Recent studies have established that chondrocytes also express RANKL/OPG and support osteoclast formation. Till now, the in vivo function of chondrocyte-produced OPG in osteoclast formation and postnatal bone growth has not been directly investigated. In this study, chondrocyte-specific Opg transgenic mice were generated by using type II collagen promoter. The Col2-Opg transgenic mice showed delayed formation of secondary ossification center and localized increase of bone mass in proximal metaphysis of tibiae. TRAP staining showed that osteoclast numbers were reduced in both secondary ossification center and proximal metaphysis. This finding was further confirmed by in vitro chondrocyte/spleen cell co-culture assay. In contrast, the mineral apposition rates were not changed in Col2-Opg transgenic mice. TUNEL staining revealed more apoptotic hypertrophic chondrocytes in the growth plate of Col2-Opg mice. Flow cytometry analysis showed fewer RANK-expressing cells in the marrow of Col2a1-Opg mice, suggesting the role of OPG in blocking the differentiation of early mesenchymal progenitors into RANK-expressing pre-osteoclasts. Our results demonstrated that OPG expression in chondrocyte increases bone mass in the proximal metaphysis of tibiae through negative regulation of osteoclast formation.
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Affiliation(s)
- Baoli Wang
- Key Lab of Hormone and Development (Ministry of Health), Metabolic Diseases Hospital and Tianjin Institute of Endocrinology, Tianjin Medical University, Tianjin 300070, China.,Department of Orthopaedics, Center for Musculoskeletal Research, University of Rochester School of Medicine, Rochester, NY 14642, USA
| | - Hongting Jin
- Department of Orthopaedics, Center for Musculoskeletal Research, University of Rochester School of Medicine, Rochester, NY 14642, USA
| | - Bing Shu
- Department of Orthopaedics, Center for Musculoskeletal Research, University of Rochester School of Medicine, Rochester, NY 14642, USA
| | - Ranim R Mira
- Department of Biochemistry, Rush University Medical Center, Chicago, IL 60612, USA
| | - Di Chen
- Department of Orthopaedics, Center for Musculoskeletal Research, University of Rochester School of Medicine, Rochester, NY 14642, USA.,Department of Biochemistry, Rush University Medical Center, Chicago, IL 60612, USA
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23
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Martin A, Xiong J, Koromila T, Ji JS, Chang S, Song YS, Miller JL, Han CY, Kostenuik P, Krum SA, Chimge NO, Gabet Y, Frenkel B. Estrogens antagonize RUNX2-mediated osteoblast-driven osteoclastogenesis through regulating RANKL membrane association. Bone 2015; 75:96-104. [PMID: 25701138 PMCID: PMC4387095 DOI: 10.1016/j.bone.2015.02.007] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/19/2014] [Revised: 02/04/2015] [Accepted: 02/08/2015] [Indexed: 01/17/2023]
Abstract
In addition to its thoroughly investigated role in bone formation, the osteoblast master transcription factor RUNX2 also promotes osteoclastogenesis and bone resorption. Here we demonstrate that 17β-estradiol (E2), strongly inhibits RUNX2-mediated osteoblast-driven osteoclastogenesis in co-cultures. Towards deciphering the underlying mechanism, we induced premature expression of RUNX2 in primary murine pre-osteoblasts, which resulted in robust differentiation of co-cultured splenocytes into mature osteoclasts. This was attributable to RUNX2-mediated increase in RANKL secretion, determined by ELISA, as well as to RUNX2-mediated increase in RANKL association with the osteoblast membrane, demonstrated using confocal fluorescence microscopy. The increased association with the osteoblast membrane was recapitulated by transiently expressed GFP-RANKL. E2 abolished the RUNX2-mediated increase in membrane-associated RANKL and GFP-RANKL, as well as the concomitant osteoclastogenesis. RUNX2-mediated RANKL cellular redistribution was attributable in part to a decrease in Opg expression, but E2 did not influence Opg expression either in the presence or absence of RUNX2. Diminution of RUNX2-mediated osteoclastogenesis by E2 occurred regardless of whether the pre-osteoclasts were derived from wild type or estrogen receptor alpha (ERα)-knockout mice, suggesting that activated ERα inhibited osteoblast-driven osteoclastogenesis by acting in osteoblasts, possibly targeting RUNX2. Indeed, microarray analysis demonstrated global attenuation of the RUNX2 response by E2, including abrogation of Pstpip2 expression, which likely plays a critical role in membrane trafficking. Finally, the selective ER modulators (SERMs) tamoxifen and raloxifene mimicked E2 in abrogating the stimulatory effect of osteoblastic RUNX2 on osteoclast differentiation in the co-culture assay. Thus, E2 antagonizes RUNX2-mediated RANKL trafficking and subsequent osteoclastogenesis. Targeting RUNX2 and/or downstream mechanisms that regulate RANKL trafficking may lead to the development of improved SERMs and possibly non-hormonal therapeutic approaches to high turnover bone disease.
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Affiliation(s)
- Anthony Martin
- Department of Biochemistry and Molecular Biology, University of Southern California, 1795 Zonal Ave, Los Angeles, CA, 90033, USA
- Institute for Genetic Medicine, Keck School of Medicine, University of Southern California, 1795 Zonal Ave, Los Angeles, CA, 90033, USA
| | - Jian Xiong
- Department of Biochemistry and Molecular Biology, University of Southern California, 1795 Zonal Ave, Los Angeles, CA, 90033, USA
- Institute for Genetic Medicine, Keck School of Medicine, University of Southern California, 1795 Zonal Ave, Los Angeles, CA, 90033, USA
| | - Theodora Koromila
- Department of Biochemistry and Molecular Biology, University of Southern California, 1795 Zonal Ave, Los Angeles, CA, 90033, USA
- Institute for Genetic Medicine, Keck School of Medicine, University of Southern California, 1795 Zonal Ave, Los Angeles, CA, 90033, USA
| | - Jie S. Ji
- Department of Biochemistry and Molecular Biology, University of Southern California, 1795 Zonal Ave, Los Angeles, CA, 90033, USA
- Institute for Genetic Medicine, Keck School of Medicine, University of Southern California, 1795 Zonal Ave, Los Angeles, CA, 90033, USA
| | - Stephanie Chang
- Institute for Genetic Medicine, Keck School of Medicine, University of Southern California, 1795 Zonal Ave, Los Angeles, CA, 90033, USA
| | - Yae S. Song
- Institute for Genetic Medicine, Keck School of Medicine, University of Southern California, 1795 Zonal Ave, Los Angeles, CA, 90033, USA
| | - Jonathan L. Miller
- Institute for Genetic Medicine, Keck School of Medicine, University of Southern California, 1795 Zonal Ave, Los Angeles, CA, 90033, USA
| | - Chun-Ya Han
- Metabolic Disorders Research, Amgen Inc., 1 Amgen Center Dr, Thousand Oaks, CA, 91320, USA
| | - Paul Kostenuik
- Metabolic Disorders Research, Amgen Inc., 1 Amgen Center Dr, Thousand Oaks, CA, 91320, USA
| | - Susan A. Krum
- UCLA and Orthopaedic Hospital Department of Orthopaedic Surgery and the Orthopaedic Hospital Research Center, David Geffen School of Medicine, UCLA, 10833 Le Conte Ave, Los Angeles, CA, 90095 USA
| | - Nyam-Osor Chimge
- Department of Medicine, University of Southern California, 1795 Zonal Ave, Los Angeles, CA, 90033, USA
- Institute for Genetic Medicine, Keck School of Medicine, University of Southern California, 1795 Zonal Ave, Los Angeles, CA, 90033, USA
| | - Yankel Gabet
- Department of Anatomy and Anthropology, Sackler Faculty of Medicine, Tel Aviv University, P.O. Box 39040, Tel Aviv, 69978 Israel
| | - Baruch Frenkel
- Department of Biochemistry and Molecular Biology, University of Southern California, 1795 Zonal Ave, Los Angeles, CA, 90033, USA
- Department of Orthopaedic Surgery, University of Southern California, 1795 Zonal Ave, Los Angeles, CA, 90033, USA
- Institute for Genetic Medicine, Keck School of Medicine, University of Southern California, 1795 Zonal Ave, Los Angeles, CA, 90033, USA
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Bonura F. Prevention, Screening, and Management of Osteoporosis: An Overview of the Current Strategies. Postgrad Med 2015; 121:5-17. [DOI: 10.3810/pgm.2009.07.2021] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Liu R, Jin C, Wang Z, Wang Z, Wang J, Wang L. Effects of manganese deficiency on the microstructure of proximal tibia and OPG/RANKL gene expression in chicks. Vet Res Commun 2015; 39:31-7. [PMID: 25634035 DOI: 10.1007/s11259-015-9626-5] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2014] [Accepted: 01/06/2015] [Indexed: 11/28/2022]
Abstract
Manganese (Mn) deficiency can result in perosis in chicks, but the mechanism of Mn deficiency on tibia development remains poorly understood. Ninety one-day-old Arbor Acres male broiler chickens administered with control diet (60 mg Mn/kg) and Mn-deficient diets (40 mg Mn/kg, 8.7 mg Mn/kg) to investigate the effects of Mn deficiency on morphology of tibia and related signal transduction pathways in broiler chickens. At the age of 42 days, the bone trabecula, damaged osteoblasts and OPG/RANKL mRNA expression levels were investigated by histological assessment, electron microscopic examination and real-time quantitative PCR analysis, respectively. Results of histological observations showed that decreased trabecular thickness, trabecular number and trabecular bone area (%) together with increased trabecular bone separation were involved in perosis induced by Mn deficiency. The most striking ultrastructural modifications involved disruption of nuclear membrane and mitochondria outer membrane, loss of mitochondrion cristae and alteration in endoplasmic reticulum in osteoblasts of the Mn-deficient groups. Likewise, Mn deficiency results in a significant (P < 0.05) decrease in the relative mRNA expression levels of OPG and RANKL with a significantly higher RANKL/OPG ratio (P < 0.05). In conclusion, Mn deficiency can affect the development of tibia in broiler chickens, leading to metaphyseal osteoporosis which may be due to decreased OPG/RANKL mRNA expression.
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Affiliation(s)
- Ran Liu
- College of Animal Science and Veterinary Medicine, Shandong Agricultural University, Daizong Road No. 61, Taian, 271018, People's Republic of China
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Sun X, Yang K, Wang C, Cao S, Merritt M, Hu Y, Xu X. Paradoxical response to mechanical unloading in bone loss, microarchitecture, and bone turnover markers. Int J Med Sci 2015; 12:270-9. [PMID: 25798053 PMCID: PMC4366632 DOI: 10.7150/ijms.11078] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/16/2014] [Accepted: 01/27/2015] [Indexed: 11/23/2022] Open
Abstract
BACKGROUND Sclerostin, encoded by the SOST gene, has been implicated in the response to mechanical loading in bone. Some studies demonstrated that unloading leads to up-regulated SOST expression, which may induce bone loss. PURPOSE Most reported studies regarding the changes caused by mechanical unloading were only based on a single site. Considering that the longitudinal bone growth leads to cells of different age with different sensitivity to unloading, we hypothesized that bone turnover in response to unloading is site specific. METHODS We established a disuse rat model by sciatic neurectomy in tibia. In various regions at two time-points, we evaluated the bone mass and microarchitecture in surgically-operated rats and control rats by micro-Computed Tomography (micro-CT) and histology, sclerostin/SOST by immunohistochemistry, enzyme-linked immunosorbent assay (ELISA), and quantitative reverse transcription polymerase chain reaction (qPCR), tartrate resistant acid phosphatase 5b (TRAP 5b) by ELISA and TRAP staining, and other bone markers by ELISA. RESULTS Micro-CT and histological analysis confirmed bone volume in the disuse rats was significantly decreased compared with those in the time-matched control rats, and microarchitecture also changed 2 and 8 weeks after surgery. Compared with the control groups, SOST mRNA expression in the diaphysis was down-regulated at both week 2 and 8. On the contrary, the percentage of sclerostin-positive osteocytes showed an up-regulated response in the 5 - 6 mm region away from the growth plate, while in the 2.5 - 3.5 mm region, the percentage was no significant difference. Nevertheless, in 0.5 - 1.5 mm region, the percentage of sclerostin-positive osteocytes decreased after 8 weeks, consistent with serum SOST level. Besides, the results of TRAP also suggested that the expression in response to unloading may be opposite in different sites or system. CONCLUSION Our data indicated that unloading-induced changes in bone turnover are probably site specific. This implies a more complex response pattern to unloading and unpredictable therapeutics which target SOST or TRAP 5b.
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Affiliation(s)
- Xiaodi Sun
- 1. School of Stomatology, Shandong University, Wenhuaxi Road 44-1, Jinan 250012, China. ; 3. Shandong Provincial Key Laboratory of Oral Biomedicine, Jinan, China
| | - Kaiyun Yang
- 2. Institute of Dental Medicine, Qilu Hospital, Shandong University, Wenhuaxi Road 107, Jinan 250012, China
| | - Chune Wang
- 2. Institute of Dental Medicine, Qilu Hospital, Shandong University, Wenhuaxi Road 107, Jinan 250012, China
| | - Sensen Cao
- 2. Institute of Dental Medicine, Qilu Hospital, Shandong University, Wenhuaxi Road 107, Jinan 250012, China
| | - Mackenzie Merritt
- 4. Department of Biology, Faculty of Science, University of Waterloo, 200 University Ave W, Waterloo, Ontario, Canada, N2L 3G1
| | - Yingwei Hu
- 2. Institute of Dental Medicine, Qilu Hospital, Shandong University, Wenhuaxi Road 107, Jinan 250012, China
| | - Xin Xu
- 1. School of Stomatology, Shandong University, Wenhuaxi Road 44-1, Jinan 250012, China. ; 3. Shandong Provincial Key Laboratory of Oral Biomedicine, Jinan, China
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Zidan RA, Elnegris HM. Effect of homocysteine on the histological structure of femur in young male albino rats and the possible protective role of folic acid. ACTA ACUST UNITED AC 2015. [DOI: 10.7243/2055-091x-2-16] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Solberg LB, Stang E, Brorson SH, Andersson G, Reinholt FP. Tartrate-resistant acid phosphatase (TRAP) co-localizes with receptor activator of NF-KB ligand (RANKL) and osteoprotegerin (OPG) in lysosomal-associated membrane protein 1 (LAMP1)-positive vesicles in rat osteoblasts and osteocytes. Histochem Cell Biol 2014; 143:195-207. [PMID: 25201349 PMCID: PMC4298672 DOI: 10.1007/s00418-014-1272-4] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/26/2014] [Indexed: 12/19/2022]
Abstract
Tartrate-resistant acid phosphatase (TRAP) is well known as an osteoclast marker; however, a recent study from our group demonstrated enhanced number of TRAP + osteocytes as well as enhanced levels of TRAP located to intracellular vesicles in osteoblasts and osteocytes in experimental osteoporosis in rats. Such vesicles were especially abundant in osteoblasts and osteocytes in cancellous bone as well as close to bone surface and intracortical remodeling sites. To further investigate TRAP in osteoblasts and osteocytes, long bones from young, growing rats were examined. Immunofluorescence confocal microscopy displayed co-localization of TRAP with receptor activator of NF-KB ligand (RANKL) and osteoprotegerin (OPG) in hypertrophic chondrocytes and diaphyseal osteocytes with Pearson's correlation coefficient ≥0.8. Transmission electron microscopy showed co-localization of TRAP and RANKL in lysosomal-associated membrane protein 1 (LAMP1) + vesicles in osteoblasts and osteocytes supporting the results obtained by confocal microscopy. Recent in vitro data have demonstrated OPG as a traffic regulator for RANKL to LAMP1 + secretory lysosomes in osteoblasts and osteocytes, which seem to serve as temporary storage compartments for RANKL. Our in situ observations indicate that TRAP is located to RANKL-/OPG-positive secretory lysosomes in osteoblasts and osteocytes, which may have implications for osteocyte regulation of osteoclastogenesis.
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Affiliation(s)
- L B Solberg
- Department of Pathology, The Core Facility for Advanced Electron Microscopy, Oslo University Hospital, Rikshospitalet, P.O. Box 4950, Nydalen, 0424, Oslo, Norway,
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Xiong J, Piemontese M, Thostenson JD, Weinstein RS, Manolagas SC, O'Brien CA. Osteocyte-derived RANKL is a critical mediator of the increased bone resorption caused by dietary calcium deficiency. Bone 2014; 66:146-54. [PMID: 24933342 PMCID: PMC4125539 DOI: 10.1016/j.bone.2014.06.006] [Citation(s) in RCA: 82] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/05/2014] [Revised: 06/03/2014] [Accepted: 06/04/2014] [Indexed: 11/23/2022]
Abstract
Parathyroid hormone (PTH) excess stimulates bone resorption. This effect is associated with increased expression of the osteoclastogenic cytokine receptor activator of nuclear factor κB ligand (RANKL) in bone. However, several different cell types, including bone marrow stromal cells, osteocytes, and T lymphocytes, express both RANKL and the PTH receptor and it is unclear whether RANKL expression by any of these cell types is required for PTH-induced bone loss. Here we have used mice lacking the RANKL gene in osteocytes to determine whether RANKL produced by this cell type is required for the bone loss caused by secondary hyperparathyroidism induced by dietary calcium deficiency in adult mice. Thirty days of dietary calcium deficiency caused bone loss in control mice, but this effect was blunted in mice lacking RANKL in osteocytes. The increase in RANKL expression in bone and the increase in osteoclast number caused by dietary calcium deficiency were also blunted in mice lacking RANKL in osteocytes. These results demonstrate that RANKL produced by osteocytes contributes to the increased bone resorption and the bone loss caused by secondary hyperparathyroidism, strengthening the evidence that osteocytes are an important target cell for hormonal control of bone remodeling.
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Affiliation(s)
- Jinhu Xiong
- Center for Osteoporosis and Metabolic Bone Diseases, University of Arkansas for Medical Sciences, Little Rock, AR, USA; Central Arkansas Veterans Healthcare System, Little Rock, AR, USA
| | - Marilina Piemontese
- Center for Osteoporosis and Metabolic Bone Diseases, University of Arkansas for Medical Sciences, Little Rock, AR, USA; Central Arkansas Veterans Healthcare System, Little Rock, AR, USA
| | - Jeff D Thostenson
- Department of Biostatistics, University of Arkansas for Medical Sciences, Little Rock, AR, USA
| | - Robert S Weinstein
- Center for Osteoporosis and Metabolic Bone Diseases, University of Arkansas for Medical Sciences, Little Rock, AR, USA; Central Arkansas Veterans Healthcare System, Little Rock, AR, USA
| | - Stavros C Manolagas
- Center for Osteoporosis and Metabolic Bone Diseases, University of Arkansas for Medical Sciences, Little Rock, AR, USA; Central Arkansas Veterans Healthcare System, Little Rock, AR, USA
| | - Charles A O'Brien
- Center for Osteoporosis and Metabolic Bone Diseases, University of Arkansas for Medical Sciences, Little Rock, AR, USA; Central Arkansas Veterans Healthcare System, Little Rock, AR, USA.
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Kennedy OD, Laudier DM, Majeska RJ, Sun HB, Schaffler MB. Osteocyte apoptosis is required for production of osteoclastogenic signals following bone fatigue in vivo. Bone 2014; 64:132-7. [PMID: 24709687 PMCID: PMC4070223 DOI: 10.1016/j.bone.2014.03.049] [Citation(s) in RCA: 104] [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: 11/04/2013] [Revised: 03/07/2014] [Accepted: 03/27/2014] [Indexed: 02/05/2023]
Abstract
Osteocyte apoptosis is spatially, temporally and functionally linked to the removal and replacement of microdamage in the bone. Recently we showed that microdamage elicits distinct responses in two populations of osteocytes near the injury site. Osteocytes directly adjacent to microdamage undergo apoptosis, whereas there is a second group of osteocytes located adjacent to the apoptotic population that upregulate expression of osteoclastogenic signaling molecules. In this study we used the pan-caspase inhibitor QVD to test the hypothesis that osteocyte apoptosis is an obligatory step in the production of key osteoclastogenic signals by in situ osteocytes in fatigue-damaged bone. We found, based on real-time PCR and immunohistochemistry assays, that expression of the apoptosis marker caspase-3 as well osteoclastogenic proteins RANKL and VEGF were increased following fatigue, while expression of the RANKL antagonist OPG decreased. However, when apoptosis was inhibited using QVD, these changes in gene expression were completely blocked. This dependence on apoptosis for neighboring non-apoptotic cells to produce signals that promote tissue remodeling also occurs in response to focal ischemic injury in the brain and heart, indicating that osteoclastic bone remodeling follows a common paradigm for localized tissue repair.
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Affiliation(s)
- Oran D Kennedy
- Department of Biomedical Engineering, The City College of New York of the City University of New York, New York, NY, USA.
| | - Damien M Laudier
- Department of Biomedical Engineering, The City College of New York of the City University of New York, New York, NY, USA
| | - Robert J Majeska
- Department of Biomedical Engineering, The City College of New York of the City University of New York, New York, NY, USA.
| | - Hui B Sun
- Department Radiation Oncology, Albert Einstein College of Medicine, Bronx, NY, USA; Department of Radiation Oncology, Albert Einstein College of Medicine, Bronx, NY, USA.
| | - Mitchell B Schaffler
- Department of Biomedical Engineering, The City College of New York of the City University of New York, New York, NY, USA.
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Abstract
Osteogenesis and bone remodeling are complex biological processes that are essential for the formation of new bone tissue and its correct functioning. When the balance between bone resorption and formation is disrupted, bone diseases and disorders such as Paget's disease, fibrous dysplasia, osteoporosis and fragility fractures may result. Recent advances in bone cell biology have revealed new specific targets for the treatment of bone loss that are based on the inhibition of bone resorption by osteoclasts or the stimulation of bone formation by osteoblasts. Bisphosphonates, antiresorptive agents that reduce bone resorption, are usually recommended as first-line therapy in women with postmenopausal osteoporosis. Numerous studies have shown that bisphosphonates are able to significantly reduce the risk of femoral and vertebral fractures. Other antiresorptive agents indicated for the treatment of osteoporosis include selective estrogen receptor modulators, such as raloxifene. Denosumab, a human monoclonal antibody, is another antiresorptive agent that has been approved in Europe and the USA. This agent blocks the RANK/RANKL/OPG system, which is responsible for osteoclastic activation, thus reducing bone resorption. Other approved agents include bone anabolic agents, such as teriparatide, a recombinant parathyroid hormone that improves bone microarchitecture and strength, and strontium ranelate, considered to be a dual-action drug that acts by both osteoclastic inhibition and osteoblastic stimulation. Currently, anti-catabolic drugs that act through the Wnt-β catenin signaling pathway, serving as Dickkopf-related protein 1 inhibitors and sclerostin antagonists, are also in development. This concise review provides an overview of the drugs most commonly used for the control of osteogenesis in bone diseases.
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Wang B, Jin H, Zhu M, Li J, Zhao L, Zhang Y, Tang D, Xiao G, Xing L, Boyce BF, Chen D. Chondrocyte β-catenin signaling regulates postnatal bone remodeling through modulation of osteoclast formation in a murine model. Arthritis Rheumatol 2014; 66:107-20. [PMID: 24431282 DOI: 10.1002/art.38195] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2012] [Accepted: 09/05/2013] [Indexed: 12/18/2022]
Abstract
OBJECTIVE To investigate whether β-catenin signaling in chondrocytes regulates osteoclastogenesis, thereby contributing to postnatal bone growth and bone remodeling. METHODS Mice with conditional knockout (cKO) or conditional activation (cAct) of chondrocyte-specific β-catenin were generated. Changes in bone mass, osteoclast numbers, and osteoblast activity were examined. The mechanisms by which β-catenin signaling in chondrocytes regulates osteoclast formation were determined. RESULTS The β-catenin cKO mice developed localized bone loss, whereas cAct mice developed a high bone mass phenotype. Histologic findings suggested that these phenotypes were caused primarily by impaired osteoclast formation, rather than impaired bone formation. Further molecular signaling analyses revealed that β-catenin signaling controlled this process by regulating the expression of the RANKL and osteoprotegerin (OPG) genes in chondrocytes. Activation of β-catenin signaling in chondrocytes suppressed Rankl gene transcription through a glucocorticoid receptor-dependent mechanism. The severe bone loss phenotype observed in β-catenin cKO mice was largely restored by treatment with human recombinant OPG or transgenic overexpression of Opg in chondrocytes. CONCLUSION β-catenin signaling in chondrocytes plays a key role in postnatal bone growth and bone remodeling through its regulation of osteoclast formation.
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Affiliation(s)
- Baoli Wang
- University of Rochester, Rochester, New York; Metabolic Diseases Hospital and Tianjin Medical University, Tianjin, China
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Stock M, Böhm C, Scholtysek C, Englbrecht M, Fürnrohr BG, Klinger P, Gelse K, Gayetskyy S, Engelke K, Billmeier U, Wirtz S, van den Berg W, Schett G. Wnt inhibitory factor 1 deficiency uncouples cartilage and bone destruction in tumor necrosis factor α-mediated experimental arthritis. ACTA ACUST UNITED AC 2013; 65:2310-22. [PMID: 23784913 DOI: 10.1002/art.38054] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2012] [Accepted: 06/06/2013] [Indexed: 12/14/2022]
Abstract
OBJECTIVE Wnt signaling plays a pivotal role in skeletal development and in the control of cartilage and bone turnover. We have recently shown that the secreted Wnt antagonist Wnt inhibitory factor 1 (WIF-1) is mainly expressed in the upper layers of epiphyseal and articular cartilage and, to a lesser extent, in bone. Nevertheless, WIF-1(-/-) mice develop normally. In light of these findings, we undertook this study to analyze the role of WIF-1 in arthritis. METHODS Expression analyses for WIF-1 were performed by real-time reverse transcription-polymerase chain reaction (RT-PCR). WIF-1(-/-) and tumor necrosis factor (TNF)-transgenic mice were crossbred, and the progression of arthritis in TNF-transgenic WIF-1(-/-) mice and littermate controls was evaluated. Structural joint damage was analyzed by histologic staining, histomorphometry, and micro-computed tomography. Wnt/β-catenin signaling was investigated by real-time RT-PCR and immunofluorescence on primary chondrocytes. RESULTS WIF-1 expression was repressed by TNFα in chondrocytes and osteoblasts and down-regulated in experimental arthritis and in articular cartilage from patients with rheumatoid arthritis. WIF-1 deficiency partially protected TNF-transgenic mice against bone erosion and loss of trabecular bone, probably as a result of less osteoclast activity. In contrast, arthritis-related cartilage damage was aggravated by WIF-1 deficiency, while overexpression of WIF-1 attenuated cartilage degradation in TNF-transgenic mice. In chondrocytes, TNFα stimulated canonical Wnt signaling, which could be blocked by WIF-1, indicating a direct effect of TNFα and WIF-1 on Wnt signaling in this system. CONCLUSION These data suggest that WIF-1 may take part in the fine-tuning of cartilage and bone turnover, promoting the balance of cartilage versus bone anabolism.
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Abstract
Few investigators think of bone as an endocrine gland, even after the discovery that osteocytes produce circulating fibroblast growth factor 23 that targets the kidney and potentially other organs. In fact, until the last few years, osteocytes were perceived by many as passive, metabolically inactive cells. However, exciting recent discoveries have shown that osteocytes encased within mineralized bone matrix are actually multifunctional cells with many key regulatory roles in bone and mineral homeostasis. In addition to serving as endocrine cells and regulators of phosphate homeostasis, these cells control bone remodeling through regulation of both osteoclasts and osteoblasts, are mechanosensory cells that coordinate adaptive responses of the skeleton to mechanical loading, and also serve as a manager of the bone's reservoir of calcium. Osteocytes must survive for decades within the bone matrix, making them one of the longest lived cells in the body. Viability and survival are therefore extremely important to ensure optimal function of the osteocyte network. As we continue to search for new therapeutics, in addition to the osteoclast and the osteoblast, the osteocyte should be considered in new strategies to prevent and treat bone disease.
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Affiliation(s)
- Sarah L Dallas
- PhD, Department of Oral and Craniofacial Sciences, School of Dentistry, University of Missouri-Kansas City, 650 East 25th Street, Kansas City, Missouri 64108.
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Effects of dietary energy and calcium levels on performance, egg shell quality and bone metabolism in hens. Vet J 2013; 198:252-8. [PMID: 24054908 DOI: 10.1016/j.tvjl.2013.07.017] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2013] [Revised: 06/06/2013] [Accepted: 07/10/2013] [Indexed: 11/21/2022]
Abstract
This study investigated the effects of dietary energy and calcium levels on laying performance, eggshell quality and bone metabolism of layers. One hundred and sixty-two 19-week-old Hy-Line brown laying hens in 54 battery cages were allocated to one of nine dietary treatments with control, middle and high levels of energy (11.50, 12.68 and 13.37 MJ/kg, respectively) and low, control and high levels of calcium (2.62%, 3.7% and 4.4%, respectively) for 60 days, using a 3 × 3 factorial arrangement. Compared with the control energy diet, high- and middle-energy diets increased fat deposition and egg weight, decreased feed intake and bone quality and had no effects on eggshell quality. The high-energy diet reduced the serum phosphate concentration and elevated osteocalcin mRNA expression in the keel bone without increasing osteocalcin protein. Dietary calcium intake did not affect fat deposition, feed intake or egg weight. Low dietary calcium resulted in weaker eggshells and poorer bone quality than that from hens fed the control diet. High dietary calcium increased serum calcium concentration, osteoprotegerin mRNA and osteocalcin protein and inhibited serum alkaline phosphatase activity and decreased its mRNA compared with low or control dietary calcium. The high-energy and high-calcium diet significantly reduced egg production. Compared with the control energy diet, high- and middle-energy diets increased fat deposition but had negative effects on bone metabolic homeostasis. Dietary calcium did not influence fat deposition but a high-calcium diet benefited bone homeostasis, while a low-calcium diet was associated with poorer eggshell quality and bone homeostasis.
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Golovchenko S, Hattori T, Hartmann C, Gebhardt M, Gebhard S, Hess A, Pausch F, Schlund B, von der Mark K. Deletion of beta catenin in hypertrophic growth plate chondrocytes impairs trabecular bone formation. Bone 2013; 55:102-12. [PMID: 23567158 DOI: 10.1016/j.bone.2013.03.019] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/12/2013] [Revised: 03/22/2013] [Accepted: 03/23/2013] [Indexed: 12/31/2022]
Abstract
In order to elucidate the role of β-catenin in hypertrophic cartilage zone of the growth plate, we deleted the β-catenin gene ctnnb1specifically from hypertrophic chondrocytes by mating ctnnb1(fl/fl) mice with BAC-Col10a1-Cre-deleter mice. Surprisingly, this resulted in a significant reduction of subchondral trabecular bone formation in BACCol10Cre; ctnnb1(Δ/Δ) (referred to as Cat-ko) mice, although Cre expression was restricted to hypertrophic chondrocytes. The size of the Col10a1 positive hypertrophic zone was normal, but qRT-PCR revealed reduced expression of Mmp13, and Vegfa in Cat-ko hypertrophic chondrocytes, indicating impaired terminal differentiation. Immunohistological and in situ hybridization analysis revealed the substantial deficiency of collagen I positive mature osteoblasts, but equal levels of osterix-positive cells in the subchondral bone marrow space of Cat-ko mice, indicating that the supply of osteoblast precursor cells was not reduced. The fact that in Cat-ko mice subchondral trabeculae were lacking including their calcified cartilage core indicated a strongly enhanced osteoclast activity. In fact, TRAP staining as well as in situ hybridization analysis of Mmp9 expression revealed denser occupation of the cartilage erosion zone with enlarged osteoclasts as compared to the control growth plate, suggesting increased RANKL or reduced osteoprotegerin (Opg) activity in this zone. This notion was confirmed by qRT-PCR analysis of mRNA extracted from cultured hypertrophic chondrocytes or from whole epiphyses, showing increased Rankl mRNA levels in Cat-ko as compared to control chondrocytes, whereas changes in OPG levels were not significant. These results indicate that β-catenin levels in hypertrophic chondrocytes play a key role in regulating osteoclast activity and trabecular bone formation at the cartilage-bone interface by controlling RANKL expression in hypertrophic chondrocytes.
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Wu Y, Zhang P, Dai Q, Fu R, Yang X, Fang B, Jiang L. Osteoclastogenesis accompanying early osteoblastic differentiation of BMSCs promoted by mechanical stretch. Biomed Rep 2013; 1:474-478. [PMID: 24648971 DOI: 10.3892/br.2013.84] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2013] [Accepted: 03/11/2013] [Indexed: 01/06/2023] Open
Abstract
Mechanical stress plays a crucial role in bone formation and absorption. In previous studies, we verified the osteoblastogenesis of bone mesenchymal stem cells (BMSCs) affected by intermittent traction stretch. However, little is known about the osteoclastogenesis process under mechanical stimulation and its underlying association with osteoblastogenesis. In the present study, we investigated the osteoclastogenesis of BMSCs under this special mechanical stress. BMSCs were subjected to 10% elongation for 1-7 days using a Flexcell Strain Unit and then the mRNA levels of osteoclastic genes were examined. The results indicated time-dependent varying of mRNA levels of the receptor activator of nuclear factor-κB ligand (RANKL) and osteoprotegerin (OPG) in BMSCs at different stretching time points. The ratio of RANKL/OPG increased at the early stage of mechanical stimulation (5 days) and decreased to a low level at a later stage (7 days). Findings of this study may help to understand the correlations between osteoblastogenesis and osteoclasteogenesis when mechanical stretch induces the osteoblastic differentiation of BMSCs.
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Affiliation(s)
- Yuqiong Wu
- Center of Craniofacial Orthodontics, Department of Oral and Cranio-Maxillofacial Science, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai Key Laboratory of Stomatology, Shanghai 200011, P.R. China
| | - Peng Zhang
- Center of Craniofacial Orthodontics, Department of Oral and Cranio-Maxillofacial Science, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai Key Laboratory of Stomatology, Shanghai 200011, P.R. China
| | - Qinggang Dai
- Center of Craniofacial Orthodontics, Department of Oral and Cranio-Maxillofacial Science, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai Key Laboratory of Stomatology, Shanghai 200011, P.R. China
| | - Runqing Fu
- Center of Craniofacial Orthodontics, Department of Oral and Cranio-Maxillofacial Science, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai Key Laboratory of Stomatology, Shanghai 200011, P.R. China
| | - Xiao Yang
- Center of Craniofacial Orthodontics, Department of Oral and Cranio-Maxillofacial Science, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai Key Laboratory of Stomatology, Shanghai 200011, P.R. China
| | - Bing Fang
- Center of Craniofacial Orthodontics, Department of Oral and Cranio-Maxillofacial Science, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai Key Laboratory of Stomatology, Shanghai 200011, P.R. China
| | - Lingyong Jiang
- Center of Craniofacial Orthodontics, Department of Oral and Cranio-Maxillofacial Science, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai Key Laboratory of Stomatology, Shanghai 200011, P.R. China
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Sinningen K, Tsourdi E, Rauner M, Rachner TD, Hamann C, Hofbauer LC. Skeletal and extraskeletal actions of denosumab. Endocrine 2012; 42:52-62. [PMID: 22581255 DOI: 10.1007/s12020-012-9696-x] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/13/2012] [Accepted: 05/02/2012] [Indexed: 01/01/2023]
Abstract
Osteoclasts and osteoblasts define skeletal mass, structure and strength through their respective actions in resorbing and forming bone. This remodeling process is orchestrated by the actions of hormones and growth factors, which regulate a cytokine system comprising the receptor activator of nuclear factor κB ligand (RANKL), its receptor RANK and the soluble decoy receptor osteoprotegerin (OPG). Bone resorption depends on RANKL, which determines osteoclast formation, activity and survival. Importantly, cells of the osteoblastic lineage mainly provide RANKL and therefore, are central in the regulation of osteoclast functions. Catabolic effects of RANKL are inhibited by OPG, a TNF receptor family member that binds RANKL, thereby preventing the activation of its receptor RANK, which is expressed by osteoclast precursors. Because this cytokine network is pivotal for the regulation of bone mass in health and diseases, including osteoporosis, rheumatoid arthritis and malignant bone conditions, it has been successfully used for the generation of a targeted therapy to block osteoclast actions. The clinical approval of denosumab, a fully monoclonal antibody against RANKL, provides a novel option to treat bone diseases with a potent, targeted and reversible inhibitor of bone resorption. Although RANKL is also expressed by endothelial cells, T lymphocytes, synovial fibroblasts and various tumor cells, no meaningful clinical extraskeletal effects have been reported after administration of denosumab. This article summarizes the molecular and cellular basis of the RANKL/RANK/OPG system and presents preclinical and clinical studies on the skeletal actions of denosumab.
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Affiliation(s)
- Kathrin Sinningen
- Division of Endocrinology, Diabetes, and Bone Diseases, Department of Medicine III, Technical University Medical Center, Fetscherstr. 74, 01307, Dresden, Germany.
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39
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Abstract
Intercellular communication within the bone microenvironment is critical for the maintenance of normal bone structure. Osteoblast-lineage cells at all stages of differentiation, from pluripotent precursors to matrix-embedded osteocytes, produce regulatory factors that modulate the differentiation and activity of both bone-forming osteoblasts and bone-resorbing osteoclasts. Osteoclasts can also release factors that feed back to regulate osteoblast activity. Intercellular cross-talk within the bone microenvironment is not restricted only to these bone cells. Other cells within the bone marrow microenvironment, including adipocytes, T cells, and macrophages, play key roles that influence the processes of bone formation and resorption. This review discusses recent work that provides new insights into some of these communication networks and the factors involved, including osteocytic production of receptor activator of nuclear factor-κB ligand (RANKL) and sclerostin, osteoblastic production of interleukin-33, osteoclast-derived Semaphorin 4D, ephrin signaling, and signals from T helper cells and resident osteal macrophages (osteomacs).
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Affiliation(s)
- Natalie A Sims
- St. Vincent's Institute of Medical Research and The University of Melbourne, 9 Princes Street, Fitzroy, 3065, Melbourne, Victoria, Australia.
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40
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Kennedy OD, Herman BC, Laudier DM, Majeska RJ, Sun HB, Schaffler MB. Activation of resorption in fatigue-loaded bone involves both apoptosis and active pro-osteoclastogenic signaling by distinct osteocyte populations. Bone 2012; 50:1115-22. [PMID: 22342796 PMCID: PMC3366436 DOI: 10.1016/j.bone.2012.01.025] [Citation(s) in RCA: 188] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/18/2011] [Revised: 01/17/2012] [Accepted: 01/30/2012] [Indexed: 01/19/2023]
Abstract
Osteocyte apoptosis is required to initiate osteoclastic bone resorption following fatigue-induced microdamage in vivo; however, it is unclear whether apoptotic osteocytes also produce the signals that induce osteoclast differentiation. We determined the spatial and temporal patterns of osteocyte apoptosis and expression of pro-osteoclastogenic signaling molecules in vivo. Ulnae from female Sprague-Dawley rats (16-18weeks old) were cyclically loaded to a single fatigue level, and tissues were analyzed 3 and 7days later (prior to the first appearance of osteoclasts). Expression of genes associated with osteoclastogenesis (RANKL, OPG, VEGF) and apoptosis (caspase-3) were assessed by qPCR using RNA isolated from 6mm segments of ulnar mid-diaphysis, with confirmation and spatial localization of gene expression performed by immunohistochemistry. A novel double staining immunohistochemistry method permitted simultaneous localization of apoptotic osteocytes and osteocytes expressing pro-osteoclastogenic signals relative to microdamage sites. Osteocyte staining for caspase-3 and osteoclast regulatory signals exhibited different spatial distributions, with apoptotic (caspase 3-positive) cells highest in the damage region and declining to control levels within several hundred microns of the microdamage focus. Cells expressing RANKL or VEGF peaked between 100 and 300μm from the damage site, then returned to control levels beyond this distance. Conversely, osteocytes in non-fatigued control bones expressed OPG. However, OPG staining was reduced markedly in osteocytes immediately surrounding microdamage. These results demonstrate that while osteocyte apoptosis triggers the bone remodeling response to microdamage, the neighboring non-apoptotic osteocytes are the major source of pro-osteoclastogenic signals. Moreover, both the apoptotic and osteoclast-signaling osteocyte populations are localized in a spatially and temporally restricted pattern consistent with the targeted nature of this remodeling response.
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Affiliation(s)
- Oran D. Kennedy
- Department of Biomedical Engineering, The City College of New York, New York, NY 10031, USA
| | - Brad C. Herman
- Department of Orthopaedics, Mount Sinai School of Medicine, New York, NY 10029, USA
| | - Damien M. Laudier
- Department of Biomedical Engineering, The City College of New York, New York, NY 10031, USA
| | - Robert J. Majeska
- Department of Biomedical Engineering, The City College of New York, New York, NY 10031, USA
| | - Hui B. Sun
- Department of Orthopaedics, Mount Sinai School of Medicine, New York, NY 10029, USA
| | - Mitchell B. Schaffler
- Department of Biomedical Engineering, The City College of New York, New York, NY 10031, USA
- Corresponding author at: Department of Biomedical Engineering, The City College of New York, 160 Convent Avenue, Steinman Hall, T-401, NY, NY, 10031, USA. Fax: +1 212 650 6727
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41
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Abstract
The idea that osteoblasts, or their progenitors, support osteoclast formation by expressing the cytokine receptor activator of NFkB ligand (RANKL) is a widely held tenet of skeletal biology. Two recent studies provide evidence that osteocytes, and not osteoblasts or their progenitors, are the major source of RANKL driving osteoclast formation in cancellous bone. The goal of this review is to highlight the results of these new studies and discuss their implications for our understanding of bone remodeling.
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Affiliation(s)
- Jinhu Xiong
- Center for Osteoporosis and Metabolic Bone Diseases, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
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42
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Matsuo K, Otaki N. Bone cell interactions through Eph/ephrin: bone modeling, remodeling and associated diseases. Cell Adh Migr 2012; 6:148-56. [PMID: 22660185 PMCID: PMC3499314 DOI: 10.4161/cam.20888] [Citation(s) in RCA: 118] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Bones cannot properly form or be maintained without cell-cell interactions through ephrin ligands and Eph receptors. Cell culture analysis and evaluation of genetic mouse models and human diseases reveal various ephrins and Eph functions in the skeletal system. Migration, attachment and spreading of mesenchymal stem cells are regulated by ephrinB ligands and EphB receptors. ephrinB1 loss-of-function is associated with craniofrontonasal syndrome (CFNS) in humans and mice. In bone remodeling, ephrinB2 is postulated to act as a “coupling stimulator.” In that case, bidirectional signaling between osteoclastic ephrinB2 and osteoblastic EphB4 suppresses osteoclastic bone resorption and enhances osteoblastic bone formation, facilitating the transition between these two states. Parathyroid hormone (PTH) induces ephrinB2 in osteoblasts and enhances osteoblastic bone formation. In contrast to ephrinB2, ephrinA2 acts as a “coupling inhibitor,” since ephrinA2 reverse signaling into osteoclasts enhances osteoclastogenesis and EphA2 forward signaling into osteoblasts suppresses osteoblastic bone formation and mineralization. Furthermore, ephrins and Ephs likely modulate pathological conditions such as osteoarthritis, rheumatoid arthritis, multiple myeloma and osteosarcoma. This review focuses on ephrin/Eph-mediated cell-cell interactions in bone biology.
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Affiliation(s)
- Koichi Matsuo
- Laboratory of Cell and Tissue Biology, School of Medicine, Keio University, Tokyo, Japan.
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43
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Kramer I, Baertschi S, Halleux C, Keller H, Kneissel M. Mef2c deletion in osteocytes results in increased bone mass. J Bone Miner Res 2012; 27:360-73. [PMID: 22161640 DOI: 10.1002/jbmr.1492] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Myocyte enhancer factors 2 (MEF2) are required for expression of the osteocyte bone formation inhibitor Sost in vitro, implying these transcription factors in bone biology. Here, we analyzed the in vivo function of Mef2c in osteocytes in male and female mice during skeletal growth and aging. Dmp1-Cre-induced Mef2c deficiency led to progressive decreases in Sost expression by 40% and 70% in femoral cortical bone at 3.5 months and 5 to 6 months of age. From 2 to 3 months onward, bone mass was increased in the appendicular and axial skeleton of Mef2c mutant relative to control mice. Cortical thickness and long bone and vertebral trabecular density were elevated. To assess whether the increased bone mass was related to the decreased Sost expression, we characterized 4-month-old heterozygous Sost-deficient mice. Sost heterozygotes displayed similar increases in long bone mass and density as Mef2c mutants, but the relative increases in axial skeletal parameters were mostly smaller. At the cellular level, bone formation parameters were normal in 3.5-month-old Mef2c mutant mice, whereas bone resorption parameters were significantly decreased. Correspondingly, cortical expression of the anti-osteoclastogenic factor and Wnt/β-catenin target gene osteoprotegerin (OPG) was increased by 70% in Mef2c mutant males. Furthermore, cortical expression of the Wnt signaling modulators Sfrp2 and Sfrp3 was strongly deregulated in both sexes. In contrast, heterozygous Sost deficient males displayed mildly increased osteoblastic mineral apposition rate, but osteoclast surface and cortical expression of osteoclastogenic regulators including OPG were normal and Sfrp2 and Sfrp3 were not significantly changed. Together, our data demonstrate that Mef2c regulates cortical Sfrp2 and Sfrp3 expression and is required to maintain normal Sost expression in vivo. Yet, the increased bone mass phenotype of Mef2c mutants is not directly related to the reduced Sost expression. We identified a novel function for Mef2c in control of adult bone mass by regulation of osteoclastic bone resorption.
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Affiliation(s)
- Ina Kramer
- Musculoskeletal Disease Area, Novartis Institutes for BioMedical Research, Novartis Pharma, Basel, Switzerland
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44
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Delgado-Calle J, Sañudo C, Fernández AF, García-Renedo R, Fraga MF, Riancho JA. Role of DNA methylation in the regulation of the RANKL-OPG system in human bone. Epigenetics 2012; 7:83-91. [PMID: 22207352 DOI: 10.4161/epi.7.1.18753] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Osteoblasts are specialized cells that form new bone and also indirectly influence bone resorption by producing factors that modulate osteoclast differentiation. Although the methylation of CpG islands plays an important role in the regulation of gene expression, there is still scanty information about its role in human bone. The aim of this study was to investigate the influence of CpG methylation on the transcriptional levels of two osteoblast-derived critical factors in the regulation of osteoclastogenesis: the receptor activator of nuclear factor NF-κB ligand (RANKL) and its soluble decoy receptor osteoprotegerin (OPG). Quantitative methylation specific PCR (qMSP) and pyrosequencing analysis in various cell types showed that the methylation of regulatory regions of these genes, in the vicinity of the transcription start sites, repressed gene transcription, whereas an active transcription was associated with low levels of methylation. In addition, treatment with the DNA demethylating agent 5-azadeoxycitidine promoted a 170-fold induction of RANKL and a 20-fold induction of OPG mRNA expression in HEK-293 cells, which showed hypermethylation of the CpG islands and barely expressed RANKL and OPG transcripts at baseline. Transcriptional levels of both genes were also explored in bone tissue samples from patients with hip fractures and hip osteoarthritis. Although RANKL transcript abundance and the RANKL:OPG transcript ratio were significantly higher in patients with fractures than in those with osteoarthritis (RANKL: 0.76 ± 0.23 vs. 0.24 ± 0.08, p = 0.012; RANKL/OPG: 7.66 ± 2.49 vs. 0.92 ± 0.21, p = 0.002), there was no evidence for differential methylation across patient groups. In conclusion, the association between DNA methylation and the repression of RANKL and OPG expression strongly suggests that methylation-dependent mechanisms influence the transcription of these genes, which play a critical role in osteoclastogenesis. However, other mechanisms appear to be involved in the increased RANKL/OPG ratio of patients with osteoporotic fractures.
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Affiliation(s)
- Jesús Delgado-Calle
- Department of Internal Medicine, Hospital U.M. Valdecilla-IFIMAV, University of Cantabria, RETICEF, Santander, Spain
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45
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Tsourdi E, Rachner TD, Rauner M, Hamann C, Hofbauer LC. Denosumab for bone diseases: translating bone biology into targeted therapy. Eur J Endocrinol 2011; 165:833-40. [PMID: 21852390 DOI: 10.1530/eje-11-0454] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Signalling of receptor activator of nuclear factor-κB (RANK) ligand (RANKL) through RANK is a critical pathway to regulate the differentiation and activity of osteoclasts and, hence, a master regulator of bone resorption. Increased RANKL activity has been demonstrated in diseases characterised by excessive bone loss such as osteoporosis, rheumatoid arthritis and osteolytic bone metastases. The development and approval of denosumab, a fully MAB against RANKL, has heralded a new era in the treatment of bone diseases by providing a potent, targeted and reversible inhibitor of bone resorption. This article summarises the molecular and cellular biology of the RANKL/RANK system and critically reviews preclinical and clinical studies that have established denosumab as a promising novel therapy for metabolic and malignant bone diseases. We will discuss the potential indications for denosumab along with a critical review of safety and analyse its potential within the concert of established therapies.
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Affiliation(s)
- Elena Tsourdi
- Division of Endocrinology, Diabetes, and Bone Diseases, Department of Medicine III, Technical University Medical Center, Fetscherstrasse 74, Dresden, Germany
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46
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Tanaka H, Mine T, Ogasa H, Taguchi T, Liang CT. Expression of RANKL/OPG during bone remodeling in vivo. Biochem Biophys Res Commun 2011; 411:690-4. [PMID: 21771583 DOI: 10.1016/j.bbrc.2011.07.001] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2011] [Accepted: 07/02/2011] [Indexed: 11/17/2022]
Abstract
The interaction between receptor activator of nuclear factor κB ligand (RANKL) and osteoprotegerin (OPG) plays a dominant role in osteoclastogenesis. As both proteins are produced by osteoblast lineage cells, they are considered to represent a key link between bone formation and resorption. In this study, we investigated the expression of RANKL and OPG during bone remodeling in vivo to determine the relationship between osteoclastogenic stimulation and osteoblastic differentiation. Total RNA was prepared from rat femurs after marrow ablation on days 0, 3, 6, and 9. The temporal activation patterns of osteoblast-related genes (procollagen α1 (I), alkaline phosphatase, osteopontin, and osteocalcin) were examined by Northern blot analysis. An appreciable increase in the expression of these osteoblast markers was observed on day 3. The peak increase in gene expression was observed on day 6 followed by a slight reduction by day 9. Real-time PCR analysis showed that the OPG mRNA expression was markedly upregulated on day 6 and slightly decreased on day 9. In contrast, RANKL mRNA expression was increased by more than 20-fold on day 9. The RANKL/OPG ratio, an index of osteoclastogenic stimulation, peaked on day 9. Histological analysis showed that RANKL and OPG immunoreactivity were predominantly associated with bone marrow cells. The expression of bone formation markers was activated in the bone formation phase, followed by the stimulation of RANKL/OPG expression in the bone resorption phase, which confirmed that these molecules are key factors linking bone formation to resorption during bone remodeling.
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Affiliation(s)
- H Tanaka
- Department of Orthopedic Surgery, Yamaguchi Grand Medical Center, Hofu, Japan.
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47
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Schoppet M, Kavurma MM, Hofbauer LC, Shanahan CM. Crystallizing nanoparticles derived from vascular smooth muscle cells contain the calcification inhibitor osteoprotegerin. Biochem Biophys Res Commun 2011; 407:103-7. [PMID: 21371424 DOI: 10.1016/j.bbrc.2011.02.117] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2011] [Accepted: 02/24/2011] [Indexed: 02/06/2023]
Abstract
Osteoprotegerin (OPG), a member of the TNF receptor superfamily, was initially found to modulate bone mass by blocking osteoclast maturation and function. Rodent models have also revealed a role for OPG as an inhibitor of vascular calcification. However, the precise mode of how OPG blocks mineralization is unclear. In this study, OPG was found in an in vitro assay to significantly inhibit calcification of vascular smooth muscle cells (VSMC) induced by high calcium/phosphate (Ca/P) treatment (p=0.0063), although this effect was blunted at high OPG concentrations. By confocal microscopy, OPG was detected in VSMC in the Golgi, the same localization seen in osteoblasts, which express OPG in bone. Treatment of VSMC by minerals (Ca, P, or both) induced OPG mRNA expression as assessed by real-time quantitative PCR, and VSMC derived from atherosclerotic plaque material also exhibited higher OPG expression as compared to control cells (p<0.05). Furthermore, OPG was detected by Western blotting in matrix vesicles (MV), nanoparticles that are released by VSMC with the capacity to nucleate mineral. In atherosclerotic arteries, OPG colocalized immunohistochemically with annexin VI, a calcium-dependent membrane and phospholipid binding protein found in MV. Thus, the calcification inhibitor OPG is contained in crystallizing MV and has a biphasic effect on VSMC: physiologic concentrations inhibit calcification, whereas high concentrations commonly seen in patients with vascular disease have no effect. Like other calcification inhibitors, OPG may be specifically loaded into these nanoparticles to be deposited at remote sites, where it acts to inhibit calcification.
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Affiliation(s)
- Michael Schoppet
- Division of Cardiovascular Medicine, Addenbrooke's Hospital, University of Cambridge, Cambridge, UK.
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48
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Aarthi JJ, Darendeliler MA, Pushparaj PN. Dissecting the role of the S1P/S1PR axis in health and disease. J Dent Res 2011; 90:841-54. [PMID: 21248363 DOI: 10.1177/0022034510389178] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Sphingosine-1-phosphate (S1P) is a pleiotropic sphingophospholipid generated from the phosphorylation of sphingosine by sphingosine kinases (SPHKs). S1P has been experimentally demonstrated to modulate an array of cellular processes such as cell proliferation, cell survival, cell invasion, vascular maturation, and angiogenesis by binding with any of the five known G-protein-coupled sphingosine 1 phosphate receptors (S1P1-5) on the cell surface in an autocrine as well as a paracrine manner. Recent studies have shown that the S1P receptors (S1PRs) and SPHKs are the key targets for modulating the pathophysiological consequences of various debilitating diseases, such as cancer, sepsis, rheumatoid arthritis, ulcerative colitis, and other related illnesses. In this article, we recapitulate these novel discoveries relative to the S1P/S1PR axis, necessary for the proper maintenance of health, as well as the induction of tumorigenic, angiogenic, and inflammatory stimuli that are vital for the development of various diseases, and the novel therapeutic tools to modulate these responses in oral biology and medicine.
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Affiliation(s)
- J J Aarthi
- Department of Orthodontics, Faculty of Dentistry, The University of Sydney, Sydney, New South Wales, NSW 2010, Australia
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49
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Abstract
Bone remodeling is a tightly regulated process securing repair of microdamage (targeted remodeling) and replacement of old bone with new bone through sequential osteoclastic resorption and osteoblastic bone formation. The rate of remodeling is regulated by a wide variety of calcitropic hormones (PTH, thyroid hormone, sex steroids etc.). In recent years we have come to appreciate that bone remodeling proceeds in a specialized vascular structure,--the Bone Remodeling Compartment (BRC). The outer lining of this compartment is made up of flattened cells, displaying all the characteristics of lining cells in bone including expression of OPG and RANKL. Reduced bone turnover leads to a decrease in the number of BRCs, while increased turnover causes an increase in the number of BRCs. The secretion of regulatory factors inside a confined space separated from the bone marrow would facilitate local regulation of the remodeling process without interference from growth factors secreted by blood cells in the marrow space. The BRC also creates an environment where cells inside the structure are exposed to denuded bone, which may enable direct cellular interactions with integrins and other matrix factors known to regulate osteoclast/osteoblast activity. However, the denuded bone surface inside the BRC also constitutes an ideal environment for the seeding of bone metastases, known to have high affinity for bone matrix. Circulating osteoclast- and osteoblast precursor cells have been demonstrated in peripheral blood. The dominant pathway regulating osteoclast recruitment is the RANKL/OPG system, while many different factors (RUNX, Osterix) are involved in osteoblast differentiation. Both pathways are modulated by calcitropic hormones.
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Affiliation(s)
- Erik Fink Eriksen
- Department Of Clinical Endocrinology, Oslo University Hospital, Aker, Trondheimsveien 235, 0514 Oslo, Norway.
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50
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Salari Sharif P, Asalforoush M, Ameri F, Larijani B, Abdollahi M. The effect of n-3 fatty acids on bone biomarkers in Iranian postmenopausal osteoporotic women: a randomized clinical trial. AGE (DORDRECHT, NETHERLANDS) 2010; 32:179-86. [PMID: 19967563 PMCID: PMC2861748 DOI: 10.1007/s11357-009-9122-3] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2009] [Accepted: 11/08/2009] [Indexed: 05/07/2023]
Abstract
Recently, n-3 fatty acids are in the center of attention for their potent anti-inflammatory effects. Osteoporosis as a chronic senile disease is associated with inflammation, and the role of inflammatory mediators has been demonstrated in recent years. The beneficial effects of n-3 fatty acids on bone were proven in many animal studies, while to date, no conclusive data is available in human. The aim of this study was to evaluate the impact of n-3 fatty acids on bone biomarkers in osteoporotic postmenopausal women. Twenty-five osteoporotic postmenopausal women were recruited in the study and randomized in treatment and control groups. The patients received 900 mg n-3 fatty acid capsules or placebo per day for 6 months. Serum levels of osteocalcin, bone alkaline phosphatase (BALP), calcium, vitamin D, and parathormone and urine concentration of pyridinoline (Pyd) were measured at baseline, second month, and sixth month in both groups. In the treatment group, compared with baseline, at the second month, osteocalcin increased slightly; thereafter, it showed decrement trend until the end of the study. In the control group, it decreased all over the study. None of these changes was significant. BALP showed nonsignificant decrease from baseline over the time in both groups. Urine level of Pyd decreased significantly (P < 0.05) in the treatment group, while no significant change was seen in the control group. Serum calcium and vitamin D increased in both groups; however, changes were not significant. No significant changes were seen in calcium clearance and parathormone. In conclusion, n-3 fatty acids can decrease bone resorption; however, it could not affect bone formation significantly after 6 months treatment. Further investigations are recommended.
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Affiliation(s)
- Pooneh Salari Sharif
- Medical Ethics and History of Medicine Research Center, Tehran University of Medical Sciences, Tehran, Iran.
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