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Ando Y, Tsukasaki M, Huynh NCN, Zang S, Yan M, Muro R, Nakamura K, Komagamine M, Komatsu N, Okamoto K, Nakano K, Okamura T, Yamaguchi A, Ishihara K, Takayanagi H. The neutrophil-osteogenic cell axis promotes bone destruction in periodontitis. Int J Oral Sci 2024; 16:18. [PMID: 38413562 PMCID: PMC10899642 DOI: 10.1038/s41368-023-00275-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2023] [Revised: 12/27/2023] [Accepted: 12/28/2023] [Indexed: 02/29/2024] Open
Abstract
The immune-stromal cell interactions play a key role in health and diseases. In periodontitis, the most prevalent infectious disease in humans, immune cells accumulate in the oral mucosa and promote bone destruction by inducing receptor activator of nuclear factor-κB ligand (RANKL) expression in osteogenic cells such as osteoblasts and periodontal ligament cells. However, the detailed mechanism underlying immune-bone cell interactions in periodontitis is not fully understood. Here, we performed single-cell RNA-sequencing analysis on mouse periodontal lesions and showed that neutrophil-osteogenic cell crosstalk is involved in periodontitis-induced bone loss. The periodontal lesions displayed marked infiltration of neutrophils, and in silico analyses suggested that the neutrophils interacted with osteogenic cells through cytokine production. Among the cytokines expressed in the periodontal neutrophils, oncostatin M (OSM) potently induced RANKL expression in the primary osteoblasts, and deletion of the OSM receptor in osteogenic cells significantly ameliorated periodontitis-induced bone loss. Epigenomic data analyses identified the OSM-regulated RANKL enhancer region in osteogenic cells, and mice lacking this enhancer showed decreased periodontal bone loss while maintaining physiological bone metabolism. These findings shed light on the role of neutrophils in bone regulation during bacterial infection, highlighting the novel mechanism underlying osteoimmune crosstalk.
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Affiliation(s)
- Yutaro Ando
- Department of Immunology, Graduate School of Medicine and Faculty of Medicine, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo, Japan
- Department of Microbiology, Tokyo Dental College, 2-1-14 Kanda-Misaki-cho, Chiyoda-ku, Tokyo, Japan
- Oral Health Science Center, Tokyo Dental College, 2-9-18, Kanda-Misaki-cho, Chiyoda-ku, Tokyo, Japan
| | - Masayuki Tsukasaki
- Department of Osteoimmunology, Graduate School of Medicine and Faculty of Medicine, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo, Japan.
| | - Nam Cong-Nhat Huynh
- Department of Immunology, Graduate School of Medicine and Faculty of Medicine, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo, Japan
- Unit of Prosthodontics, Laboratory of Oral-Maxillofacial Biology Faculty of Odonto-Stomatology, University of Medicine and Pharmacy at Ho Chi Minh City, Ho Chi Minh City, Vietnam
| | - Shizao Zang
- Department of Immunology, Graduate School of Medicine and Faculty of Medicine, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo, Japan
| | - Minglu Yan
- Department of Immunology, Graduate School of Medicine and Faculty of Medicine, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo, Japan
| | - Ryunosuke Muro
- Department of Immunology, Graduate School of Medicine and Faculty of Medicine, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo, Japan
| | - Kazutaka Nakamura
- Department of Immunology, Graduate School of Medicine and Faculty of Medicine, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo, Japan
- Department of Oral and Maxillofacial Surgery, Department of Sensory and Motor System Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Masatsugu Komagamine
- Department of Immunology, Graduate School of Medicine and Faculty of Medicine, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo, Japan
- Division of Rheumatology, Department of Internal Medicine, Keio University School of Medicine, Tokyo, Japan
| | - Noriko Komatsu
- Department of Immunology, Graduate School of Medicine and Faculty of Medicine, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo, Japan
| | - Kazuo Okamoto
- Department of Osteoimmunology, Graduate School of Medicine and Faculty of Medicine, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo, Japan
| | - Kenta Nakano
- Department of Laboratory Animal Medicine, Research Institute, National Center for Global Health and Medicine, Tokyo, Japan
| | - Tadashi Okamura
- Department of Laboratory Animal Medicine, Research Institute, National Center for Global Health and Medicine, Tokyo, Japan
| | - Akira Yamaguchi
- Oral Health Science Center, Tokyo Dental College, 2-9-18, Kanda-Misaki-cho, Chiyoda-ku, Tokyo, Japan
| | - Kazuyuki Ishihara
- Department of Microbiology, Tokyo Dental College, 2-1-14 Kanda-Misaki-cho, Chiyoda-ku, Tokyo, Japan
- Oral Health Science Center, Tokyo Dental College, 2-9-18, Kanda-Misaki-cho, Chiyoda-ku, Tokyo, Japan
| | - Hiroshi Takayanagi
- Department of Immunology, Graduate School of Medicine and Faculty of Medicine, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo, Japan.
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Pike JW, Lee SM, Meyer MB. Molecular insights into mineralotropic hormone inter-regulation. Front Endocrinol (Lausanne) 2023; 14:1213361. [PMID: 37441497 PMCID: PMC10334211 DOI: 10.3389/fendo.2023.1213361] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Accepted: 06/13/2023] [Indexed: 07/15/2023] Open
Abstract
The regulation of mineral homeostasis involves the three mineralotropic hormones PTH, FGF23 and 1,25-dihydroxyvitamin D3 (1,25(OH)2D3). Early research efforts focused on PTH and 1,25(OH)2D3 and more recently on FGF23 have revealed that each of these hormones regulates the expression of the other two. Despite early suggestions of transcriptional processes, it has been only recently that research effort have begun to delineate the genomic mechanisms underpinning this regulation for 1,25(OH)2D3 and FGF23; the regulation of PTH by 1,25(OH)2D3, however, remains obscure. We review here our molecular understanding of how PTH induces Cyp27b1 expression, the gene encoding the enzyme responsible for the synthesis of 1,25(OH)2D3. FGF23 and 1,25(OH)2D3, on the other hand, function by suppressing production of 1,25(OH)2D3. PTH stimulates the PKA-induced recruitment of CREB and its coactivator CBP at CREB occupied sites within the kidney-specific regulatory regions of Cyp27b1. PKA activation also promotes the nuclear translocation of SIK bound coactivators such as CRTC2, where it similarly interacts with CREB occupied Cyp27b1 sites. The negative actions of both FGF23 and 1,25(OH)2D3 appear to suppress Cyp27b1 expression by opposing the recruitment of CREB coactivators at this gene. Reciprocal gene actions are seen at Cyp24a1, the gene encoding the enzyme that degrades 1,25(OH)2D3, thereby contributing to the overall regulation of blood levels of 1,25(OH)2D3. Relative to PTH regulation, we summarize what is known of how 1,25(OH)2D3 regulates PTH suppression. These studies suggest that it is not 1,25(OH)2D3 that controls PTH levels in healthy subjects, but rather calcium itself. Finally, we describe current progress using an in vivo approach that furthers our understanding of the regulation of Fgf23 expression by PTH and 1,25(OH)2D3 and provide the first evidence that P may act to induce Fgf23 expression via a complex transcriptional mechanism in bone. It is clear, however, that additional advances will need to be made to further our understanding of the inter-regulation of each of these hormonal genes.
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Affiliation(s)
- J. Wesley Pike
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI, United States
| | - Seong Min Lee
- Department of Nutritional Sciences, University of Wisconsin-Madison, Madison, WI, United States
| | - Mark B. Meyer
- Department of Nutritional Sciences, University of Wisconsin-Madison, Madison, WI, United States
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Abstract
Bone is a living organ that exhibits active metabolic processes, presenting constant bone formation and resorption. The bone cells that maintain local homeostasis are osteoblasts, osteoclasts, osteocytes and bone marrow stem cells, their progenitor cells. Osteoblasts are the main cells that govern bone formation, osteoclasts are involved in bone resorption, and osteocytes, the most abundant bone cells, also participate in bone remodeling. All these cells have active metabolic activities, are interconnected and influence each other, having both autocrine and paracrine effects. Ageing is associated with multiple and complex bone metabolic changes, some of which are currently incompletely elucidated. Ageing causes important functional changes in bone metabolism, influencing all resident cells, including the mineralization process of the extracellular matrix. With advancing age, a decrease in bone mass, the appearance of specific changes in the local microarchitecture, a reduction in mineralized components and in load-bearing capacity, as well as the appearance of an abnormal response to different humoral molecules have been observed. The present review points out the most important data regarding the formation, activation, functioning, and interconnection of these bone cells, as well as data on the metabolic changes that occur due to ageing.
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Affiliation(s)
- Anca Cardoneanu
- Department of Rheumatology, "Grigore T. Popa" University of Medicine and Pharmacy, Iasi, Romania
- Clinical Rehabilitation Hospital, 1st Rheumatology Clinic, Iasi, Romania
| | - Ciprian Rezus
- Department of Internal Medicine, "Grigore T. Popa" University of Medicine and Pharmacy, Iasi, Romania
- IIIrd Medical Clinic, "Saint Spiridon" Clinic Emergency County Hospital, Iasi, Romania
| | - Bogdan Ionel Tamba
- Advanced Research and Development Center for Experimental Medicine (CEMEX), "Grigore T. Popa" University of Medicine and Pharmacy, Iasi, Romania.
| | - Elena Rezus
- Department of Rheumatology, "Grigore T. Popa" University of Medicine and Pharmacy, Iasi, Romania
- Clinical Rehabilitation Hospital, 1st Rheumatology Clinic, Iasi, Romania
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Omar M, Kaklamanos EG. Does the rate of orthodontic tooth movement change during pregnancy and lactation? A systematic review of the evidence from animal studies. BMC Oral Health 2020; 20:237. [PMID: 32854696 PMCID: PMC7450973 DOI: 10.1186/s12903-020-01223-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Accepted: 08/16/2020] [Indexed: 12/09/2022] Open
Abstract
Background The changes in bone homeostasis observed during pregnancy and lactation could result in alterations in the rate of orthodontic tooth movement, but research in human subjects presents significant ethical and practical limitations. Our aim was to compare the amount of orthodontic tooth movement between pregnant/lactating or not animals. Methods We searched without restrictions 8 databases and performed hand searching until July 2019 (PubMed, Central, Cochrane Database of Systematic Reviews, SCOPUS, Web of Science, Arab World Research Source, ClinicalTrials.gov, ProQuest Dissertations and Theses Global). We searched for studies comparing quantitatively the amount of orthodontic tooth movement between pregnant/lactating or not animals. Following retrieval and selection of studies, the collection of related data was performed and the risk of bias was assessed using the SYRCLE’s Risk of Bias Tool. Exploratory synthesis was carried out using the random effects model. Results Four studies were finally identified raising no specific concerns regarding bias. One study showed that lactation increased the rate of tooth movement by 50 % [p < 0.05]. Although an overall increase was noted in the pregnancy group as well, it did not reach statistical significance [3 studies, Weighted Mean Difference: 0.10; 95% Confidence Interval: − 0.04 - 0.24; p = 0.165]. Conclusions The metabolic changes occurring during pregnancy and lactation may have an impact on the rate of tooth movement in animals. Although these animal experimental results should be approached cautiously, it could be safe practice to consider the impact of these physiological changes in the clinical setting. Registration PROSPERO (CRD42018118003).
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Affiliation(s)
- Moaza Omar
- Dubai Health Authority, Dubai, United Arab Emirates
| | - Eleftherios G Kaklamanos
- Hamdan Bin Mohammed College of Dental Medicine (HBMCDM), Mohammed Bin Rashid University of Medicine and Health Sciences (MBRU), Building 34, Dubai Healthcare City, Dubai, United Arab Emirates.
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Vitamin D status influences transcriptional levels of RANKL and inflammatory biomarkers which are associated with activation of PBMC. Clin Chim Acta 2020; 507:219-223. [PMID: 32371216 DOI: 10.1016/j.cca.2020.04.041] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Revised: 04/27/2020] [Accepted: 04/27/2020] [Indexed: 12/25/2022]
Abstract
Vitamin D status is involved in the risk of many chronic diseases including cancer, inflammatory and autoimmune disease. The RANK/RANKL/OPG system is also implicated in the orchestration of immune functions. We aimed to investigate the expression of RANKL, OPG and markers of inflammation and immune activation in peripheral blood mononuclear cells (PBMC) from healthy subjects with different 25(OH)D3 plasma levels. The 25(OH)D3 plasma concentrations were assessed by HPLC. The gene expression was evaluated by qRT-PCR. The expression of CYP27B1 was lower in subjects with 25(OH)D3 levels below 50 nmol/L (deficiency) than subjects with both insufficient and sufficient levels of 25(OH)D3. In subjects with deficiency, we observed the up-regulation of RANKL, TNF-α, IFN-γ, ICAM and LFA-1, and a reduction of the anti-inflammatory cytokines IL-13 and IL-4 in comparison to other subjects. Finally, we found a negative correlation between RANKL mRNA levels and 25(OH)D3 and between 25(OH)D3 and ICAM mRNA levels. A positive correlation between ICAM and RANKL was observed. Our results give evidence of the modulatory effects of circulating 25(OH)D3 levels on gene expression of biomarkers of immune activation in PBMC, suggesting the possible use of PBMC as ex-vivo model to characterize molecular mechanisms of immune/inflammatory response in hypovitaminosis conditions.
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Abstract
Osteoporosis is a condition where bone resorption exceeds bone formation leading to degeneration. With an aging population, the prevalence of osteoporosis is on the rise. Although advances in the field have made progress in targeting the mechanisms of the disease, the efficacy of current treatments remains limited and is complicated by unexpected side effects. Therefore, to overcome this treatment gap, new approaches are needed to identify and elucidate the cellular mechanisms mediating the pathogenesis of osteoporosis, which requires a strong understanding of bone biology. This chapter will focus on bone cells (osteoclasts, osteoblasts, and osteocytes) and their role in the bone turnover process in normal physiology and in pathology. With regard to osteoclast function, the regulators and underpinning signaling pathways leading to bone resorption will be discussed. Decreased osteoblastogenesis also contributes to bone deterioration with aging and osteoporosis; hence the factors and signaling pathways mediating osteoblast formation and function will be examined. Osteocytes are mature osteoblasts embedded in bone matrix and act as endocrine cells; their role in bone health and pathology will also be reviewed. In addition, this chapter will explore the emerging role of adipocytes in bone biology and the implications of increased bone marrow fat infiltration with aging on bone degeneration. In conclusion, a greater understanding of the pathogenesis of osteoporosis is of utmost importance in order to develop more effective treatments for osteoporosis and other bone diseases.
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Affiliation(s)
- Ahmed Al Saedi
- Australian Institute for Musculoskeletal Science (AIMSS), The University of Melbourne and Western Health, St. Albans, VIC, Australia
- Department of Medicine, Melbourne Medical School - Western Precinct, The University of Melbourne, St. Albans, VIC, Australia
| | - Nicole Stupka
- Australian Institute for Musculoskeletal Science (AIMSS), The University of Melbourne and Western Health, St. Albans, VIC, Australia
- Department of Medicine, Melbourne Medical School - Western Precinct, The University of Melbourne, St. Albans, VIC, Australia
| | - Gustavo Duque
- Australian Institute for Musculoskeletal Science (AIMSS), The University of Melbourne and Western Health, St. Albans, VIC, Australia.
- Department of Medicine, Melbourne Medical School - Western Precinct, The University of Melbourne, St. Albans, VIC, Australia.
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Wu G, Zhang J, Chen W, Chen S, Huang Y, Lin R, Huang M, Li Z, Zheng L, Li X. Tougu Xiaotong capsule exerts a therapeutic effect on knee osteoarthritis by regulating subchondral bone remodeling. Mol Med Rep 2018; 19:1858-1866. [PMID: 30592265 DOI: 10.3892/mmr.2018.9778] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Accepted: 12/12/2018] [Indexed: 01/16/2023] Open
Abstract
Previous studies have shown that Tougu Xiaotong capsule (TGXTC) has therapeutic effects on knee osteoarthritis (OA) through multiple targets. However, the mechanisms of action underlying its regulation of subchondral bone reconstruction remain unclear. In this study, we investigated the effects of TGXTC on subchondral bone remodeling. Eighteen six-month-old New Zealand white rabbits of average sex were randomly divided into the normal, model and TGXTC groups. The rabbit knee OA model was induced by a modified Hulth's method in the model and TGXTC groups, but not the normal group. Five weeks postoperatively, intragastric administration of TGXTC was performed for four weeks. After drug administration, the medial femoral condyle and tibia were prepared for observation of cartilage histology via optical microscopy and micro-computed tomography, the serum was collected for biochemical parameters assay and the subchondral bone isolated from the lateral femoral condyle was collected for detection of IL-1β and TNF-α mRNA and protein by reverse transcription-quantitative polymerase chain reaction and western blot analysis, respectively. The results showed that treatment with TGXTC significantly mitigated cartilage injury and subchondral bone damage, improved the parameter of subchondral trabecular bone, decreased alkaline phosphatase and tartrate-resistant acid phosphatase activity, and significantly reducing the osteoprotegerin/receptor activator of nuclear factor-κB ligand ratio, reduced the expression of IL-1β and TNF-α mRNA and protein. These results suggest that TGXTC could delay the pathological development of OA by regulating subchondral bone remodeling through regulation of bone formation and bone resorption and its relating inflammatory factors, and this may partly explain its clinical efficacy in the treatment of knee OA.
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Affiliation(s)
- Guangwen Wu
- Academy of Integrative Medicine, Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350122, P.R. China
| | - Jiahui Zhang
- Academy of Integrative Medicine, Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350122, P.R. China
| | - Wenlie Chen
- Academy of Integrative Medicine, Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350122, P.R. China
| | - Sainan Chen
- Academy of Integrative Medicine, Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350122, P.R. China
| | - Yunmei Huang
- National Laboratory of Traditional Chinese Medicine Pharmacology (Cell Structure and Function), Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350122, P.R. China
| | - Ruhui Lin
- Academy of Integrative Medicine, Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350122, P.R. China
| | - Meiya Huang
- National Laboratory of Traditional Chinese Medicine Pharmacology (Cell Structure and Function), Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350122, P.R. China
| | - Zuanfang Li
- National Laboratory of Traditional Chinese Medicine Pharmacology (Cell Structure and Function), Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350122, P.R. China
| | - Liangpu Zheng
- Fujian Key Laboratory of Integrative Medicine on Geriatrics, Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350122, P.R. China
| | - Xihai Li
- Fujian Key Laboratory of Integrative Medicine on Geriatrics, Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350122, P.R. China
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Weaver SR, Hernandez LL. Could use of Selective Serotonin Reuptake Inhibitors During Lactation Cause Persistent Effects on Maternal Bone? J Mammary Gland Biol Neoplasia 2018; 23:5-25. [PMID: 29603039 DOI: 10.1007/s10911-018-9390-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Accepted: 03/13/2018] [Indexed: 02/07/2023] Open
Abstract
The lactating mammary gland elegantly coordinates maternal homeostasis to provide calcium for milk. During lactation, the monoamine serotonin regulates the synthesis and release of various mammary gland-derived factors, such as parathyroid hormone-related protein (PTHrP), to stimulate bone resorption. Recent evidence suggests that bone mineral lost during prolonged lactation is not fully recovered following weaning, possibly putting women at increased risk of fracture or osteoporosis. Selective Serotonin Reuptake Inhibitor (SSRI) antidepressants have also been associated with reduced bone mineral density and increased fracture risk. Therefore, SSRI exposure while breastfeeding may exacerbate lactational bone loss, compromising long-term bone health. Through an examination of serotonin and calcium homeostasis during lactation, lactational bone turnover and post-weaning recovery of bone mineral, and the effect of peripartum depression and SSRI on the mammary gland and bone, this review will discuss the hypothesis that peripartum SSRI exposure causes persistent reductions in bone mineral density through mammary-derived PTHrP signaling with bone.
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Affiliation(s)
- Samantha R Weaver
- Endocrine and Reproductive Physiology Program, University of Wisconsin-Madison, Madison, WI, USA
| | - Laura L Hernandez
- Department of Dairy Science, University of Wisconsin-Madison, Madison, WI, USA.
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Macari S, Sharma LA, Wyatt A, da Silva JM, Dias GJ, Silva TA, Szawka RE, Grattan DR. Lactation induces increases in the RANK/RANKL/OPG system in maxillary bone. Bone 2018; 110:160-169. [PMID: 29382610 DOI: 10.1016/j.bone.2018.01.032] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/18/2017] [Revised: 01/23/2018] [Accepted: 01/26/2018] [Indexed: 10/18/2022]
Abstract
The underlying causes of maxillary bone loss during lactation remain poorly understood. We evaluated the impact of lactation on physiological and mechanically-induced alveolar bone remodeling. Nulliparous non-lactating (N-LAC) and 21-day lactating (LAC) mice underwent mechanically-induced bone remodeling by orthodontic tooth movement (OTM). Micro-computed tomography (microCT) was performed in the maxilla, femur and vertebra. Tartrate-resistant-acid phosphatase (TRAP) and Masson's trichrome labelling was performed in the maxillary bone and gene expression was determined in the periodontal ligament. The effect of prolactin on osteoclast (OCL) and osteoblast (OBL) differentiation was also investigated in N-LAC and LAC mice. Lactation increased alveolar bone loss in the maxilla, femur and vertebra, while OTM was enhanced. The number of OCL and OBL was higher in the maxilla of LAC mice. OTM increased OCL in both groups; while OBL was increased only in N-LAC but not in LAC mice, in which cell numbers were already elevated. The alveolar bone loss during lactation was associated with increased expression of receptor activator of nuclear factor-KappaB (RANK), RANK ligand (RANKL), and osteoprotegerin (OPG) in the maxilla. OTM induced the same responses in N-LAC mice, whereas it had no further effect in LAC mice. Lactation enhanced differentiation of OCL and OBL from bone marrow cells, and prolactin recapitulated OCL differentiation in N-LAC mice. Thus, lactation increases physiological maxillary bone remodeling and OTM, and both require activation of RANK/RANKL/OPG system. These findings expand our knowledge of lactation-induced osteopenia and have possible impact on clinical practice regarding orthodontic treatments and dental implants in lactating women.
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Affiliation(s)
- Soraia Macari
- Departamento de Odontopediatria e Ortodontia, Faculdade de Odontologia, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.
| | - Lavanya A Sharma
- Department of Anatomy, University of Otago, Dunedin, New Zealand
| | - Amanda Wyatt
- Department of Anatomy, University of Otago, Dunedin, New Zealand
| | - Janine Maíra da Silva
- Departamento de Clínica, Patologia e Cirurgia Odontológicas, Faculdade de Odontologia, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - George J Dias
- Department of Anatomy, University of Otago, Dunedin, New Zealand
| | - Tarcília A Silva
- Departamento de Clínica, Patologia e Cirurgia Odontológicas, Faculdade de Odontologia, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Raphael E Szawka
- Departamento de Fisiologia e Biofísica, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - David R Grattan
- Department of Anatomy, University of Otago, Dunedin, New Zealand
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Wein MN. Parathyroid Hormone Signaling in Osteocytes. JBMR Plus 2017; 2:22-30. [PMID: 30283888 PMCID: PMC6124166 DOI: 10.1002/jbm4.10021] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/17/2017] [Revised: 10/10/2017] [Accepted: 10/12/2017] [Indexed: 12/13/2022] Open
Abstract
Osteocytes are the most abundant cell type in bone and play a central role in orchestrating skeletal remodeling, in part by producing paracrine‐acting factors that in turn influence osteoblast and osteoclast activity. Recent evidence has indicated that osteocytes are crucial cellular targets of parathyroid hormone (PTH). Here, we will review the cellular and molecular mechanisms through which PTH influences osteocyte function. Two well‐studied PTH target genes in osteocytes are SOST and receptor activator of NF‐κB ligand (RANKL). The molecular mechanisms through which PTH regulates expression of these two crucial target genes will be discussed. Beyond SOST and RANKL, PTH/PTH‐related peptide (PTHrP) signaling in osteocytes may directly influence the way osteocytes remodel their perilacunar environment to influence bone homeostasis in a cell‐autonomous manner. Here, I will highlight novel, additional mechanisms used by PTH and PTHrP to modulate bone homeostasis through effects in osteocytes. © 2017 The Authors. JBMR Plus is published by Wiley Periodicals, Inc. on behalf of the American Society for Bone and Mineral Research.
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Affiliation(s)
- Marc N Wein
- Endocrine Unit, Massachusetts General Hospital Harvard Medical School Boston MA USA
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11
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Shamsuzzaman S, Onal M, St John HC, Pike JW. Deletion of a Distal RANKL Gene Enhancer Delays Progression of Atherosclerotic Plaque Calcification in Hypercholesterolemic Mice. J Cell Biochem 2017; 118:4240-4253. [PMID: 28419519 DOI: 10.1002/jcb.26074] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2017] [Accepted: 04/14/2017] [Indexed: 12/18/2022]
Abstract
Receptor activator of NF-κB ligand (RANKL) is a TNF-like cytokine which mediates diverse physiological functions including bone remodeling and immune regulation. RANKL has been identified in atherosclerotic lesions; however, its role in atherosclerotic plaque development remains elusive. An enhancer located 75 kb upstream of the murine Rankl gene's transcription start site designated D5 is important for its calciotropic hormone- and cytokine-mediated expression. Here, we determined the impact of RANKL levels in atherosclerotic plaque development in the D5 enhancer-null (D5-/- ) mice in an atherogenic Apoe-/- background fed a high-fat diet (HFD). Rankl mRNA transcripts were increased in aortic arches and thoracic aortae of Apoe-/- mice; however, this increase was blunted in Apoe-/- ;D5-/- mice. Similarly, higher Rankl transcripts were identified in splenic T lymphocytes in Apoe-/- mice, and their levels were reduced in Apoe-/- ;D5-/- mice. When analyzed by micro-computed tomography (µCT), atherosclerotic plaque calcification was identified in six out of eight Apoe-/- mice, whereas only one out of eight Apoe-/- ;D5-/- mice developed plaque calcification after 12 weeks of HFD. However, following 18 weeks of HFD challenge, all of Apoe-/- and Apoe-/- ;D5-/- animals developed atherosclerotic plaque calcification. Likewise, atherosclerotic lesion sizes were site-specifically reduced in the aortic arch of Apoe-/- ;D5-/- mice at initial stage of atherosclerosis and this effect was diminished as atherosclerosis proceeded to a more advanced stage. Our data suggest that deletion of the RANKL D5 enhancer delays the progression of atherosclerotic plaque development and plaque calcification in hypercholesterolemic mice. This work provides important insight into RANKL's regulatory role in atherosclerosis. J. Cell. Biochem. 118: 4240-4253, 2017. © 2017 Wiley Periodicals, Inc.
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Affiliation(s)
- Sohel Shamsuzzaman
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin, 53706
| | - Melda Onal
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin, 53706
| | - Hillary C St John
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin, 53706
| | - J Wesley Pike
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin, 53706
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Onal M, St John HC, Danielson AL, Pike JW. Deletion of the Distal Tnfsf11 RL-D2 Enhancer That Contributes to PTH-Mediated RANKL Expression in Osteoblast Lineage Cells Results in a High Bone Mass Phenotype in Mice. J Bone Miner Res 2016; 31:416-29. [PMID: 26332516 PMCID: PMC4835217 DOI: 10.1002/jbmr.2698] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/21/2015] [Revised: 08/24/2015] [Accepted: 08/27/2015] [Indexed: 12/24/2022]
Abstract
Receptor activator of nuclear factor-κB ligand (RANKL) is a tumor necrosis factor (TNF)-like cytokine that is necessary for osteoclast formation and survival. Elevated RANKL synthesis is associated with both increased osteoclast number and bone resorption. Earlier studies identified an enhancer 76 kb upstream of the Tnfsf11 transcriptional start site (TSS) termed RL-D5 or the distal control region (DCR) that modulates RANKL expression in response to PTH, 1,25(OH)2D3,, and an array of cytokines. Mice lacking RL-D5 exhibit high bone mass associated with decreased RANKL expression in bone, spleen, and thymus. In addition to RL-D5, genome-wide studies have identified 9 additional Tnfsf11 enhancers residing upstream of the gene's TSS, which provide RANKL cell type-specificity and responsiveness to local and systemic factors. ChIP-chip analyses has revealed inducible vitamin D receptor (VDR) and cAMP response element-binding protein (CREB) binding at an enhancer termed RL-D2 23 kb upstream of the Tnfsf11 TSS in osteoblastic ST2 cells. Herein, we use ChIP-seq analyses to confirm this finding and then delete this enhancer from the mouse genome to determine its physiological role in vivo. RL-D2(-/-) primary stromal cells showed decreased RANKL-induction by both forskolin and 1,25(OH)2D3 ex vivo. Consistent with this, the parathyroid hormone (PTH) induction of RANKL expression was significantly blunted in RL-D2(-/-) mice in vivo. In contrast, lack of RL-D2 had no effect on 1,25(OH)2D3 induction of RANKL in vivo. Similar to the results found in RL-D5(-/-) mice, lack of RL-D2 led to decreased skeletal RANKL expression, resulting in decreased osteoclast numbers and a progressive increase in bone mineral density. Lack of RL-D2 increased cancellous bone mass in femur and spine but did not alter femoral cortical bone thickness. These results highlight the role of distal enhancers in the regulation of RANKL expression by PTH and perhaps 1,25(OH)2D3 and suggest that the RL-D2 and RL-D5 enhancers contribute in either an additive or synergistic manner to regulate bone remodeling.
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Affiliation(s)
- Melda Onal
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI, USA
| | - Hillary C St John
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI, USA
| | - Allison L Danielson
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI, USA
| | - J Wesley Pike
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI, USA
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Onal M, St John HC, Danielson AL, Markert JW, Riley EM, Pike JW. Unique Distal Enhancers Linked to the Mouse Tnfsf11 Gene Direct Tissue-Specific and Inflammation-Induced Expression of RANKL. Endocrinology 2016; 157:482-96. [PMID: 26646205 PMCID: PMC4733116 DOI: 10.1210/en.2015-1788] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Receptor activator of nuclear factor κB ligand (RANKL) is expressed by a number of cell types to participate in diverse physiological functions. We have previously identified 10 distal RANKL enhancers. Earlier studies have shown that RL-D5 is a multifunctional RANKL enhancer. Deletion of RL-D5 from the mouse genome leads to lower skeletal and lymphoid tissue RANKL, causing a high bone mass phenotype. Herein, we determine the physiological role and lineage specificity of 2 additional RANKL enhancers, RL-D6 and RL-T1, which are located 83 and 123 kb upstream of the gene's transcriptional start site, respectively. Lack of RL-D6 or RL-T1 did not alter skeletal RANKL or bone mineral density up to 48 weeks of age. Although both RL-D5 and RL-T1 contributed to activation induction of T-cell RANKL, RL-T1 knockout mice had drastically low lymphocyte and lymphoid tissue RANKL levels, indicating that RL-T1 is the major regulator of lymphocyte RANKL. Moreover, RL-T1 knockout mice had lower circulating soluble RANKL, suggesting that lymphocytes are important sources of circulating soluble RANKL. Under physiological conditions, lack of RL-D6 did not alter RANKL expression. However, lack of RL-D5 or RL-D6, but not of RL-T1, blunted the oncostatin M and lipopolysaccharide induction of RANKL ex vivo and in vivo, suggesting that RL-D5 and RL-D6 coregulate the inflammation-mediated induction of RANKL in osteocytes and osteoblasts while lack of RL-D6 did not alter secondary hyperparathyroidism or lactation induction of RANKL or bone loss. These results suggest that although RL-D5 mediates RANKL expression in multiple lineages, other cell type- or factor-specific enhancers are required for its appropriate control, demonstrating the cell type-specific and complex regulation of RANKL expression.
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Affiliation(s)
- M Onal
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706
| | - H C St John
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706
| | - A L Danielson
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706
| | - J W Markert
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706
| | - E M Riley
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706
| | - J W Pike
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706
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14
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Abstract
The decrease in bone mass and strength during aging has multiple causes. Osteocytes are long-lived cells within the bone matrix that perform a variety of functions, including the control of bone remodeling. Because of their longevity, osteocytes are more likely than osteoclasts or osteoblasts to accumulate molecular damage over time. Osteocytes utilize quality-control pathways like autophagy to remove damaged organelles and macromolecules, and thereby maintain function. When the damage is excessive, cell death pathways such as apoptosis minimize the impact of potential osteocyte dysfunction on the skeleton. The goal of this review is to discuss how dysregulation of these pathways in osteocytes may contribute to the decline in bone mass and strength with age.
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Affiliation(s)
- Robert L Jilka
- Center for Osteoporosis and Metabolic Bone Diseases, Central Arkansas Veterans Healthcare System, University of Arkansas for Medical Sciences, Little Rock, AR, 72205, USA.
| | - Charles A O'Brien
- Center for Osteoporosis and Metabolic Bone Diseases, Central Arkansas Veterans Healthcare System, University of Arkansas for Medical Sciences, Little Rock, AR, 72205, USA.
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15
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Ardeshirpour L, Dumitru C, Dann P, Sterpka J, VanHouten J, Kim W, Kostenuik P, Wysolmerski J. OPG Treatment Prevents Bone Loss During Lactation But Does Not Affect Milk Production or Maternal Calcium Metabolism. Endocrinology 2015; 156:2762-73. [PMID: 25961842 PMCID: PMC4511126 DOI: 10.1210/en.2015-1232] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Lactation is associated with increased bone turnover and rapid bone loss, which liberates skeletal calcium used for milk production. Previous studies suggested that an increase in the skeletal expression of receptor activator of nuclear factor kappa-light-chain-enhancer of activated B cells ligand (RANKL) coupled with a decrease in osteoprotegerin (OPG) levels likely triggered bone loss during lactation. In this study, we treated lactating mice with recombinant OPG to determine whether bone loss during lactation was dependent on RANKL signaling and whether resorption of the maternal skeleton was required to support milk production. OPG treatment lowered bone resorption rates and completely prevented bone loss during lactation but, surprisingly, did not decrease osteoclast numbers. In contrast, OPG was quite effective at lowering osteoblast numbers and inhibiting bone formation in lactating mice. Furthermore, treatment with OPG during lactation prevented the usual anabolic response associated with reversal of lactational bone loss after weaning. Preventing bone loss had no appreciable effect on milk production, milk calcium levels, or maternal calcium homeostasis when mice were on a standard diet. However, when dietary calcium was restricted, treatment with OPG caused maternal hypocalcemia, maternal death, and decreased milk production. These studies demonstrate that RANKL signaling is a requirement for bone loss during lactation, and suggest that osteoclast activity may be required to increase osteoblast numbers during lactation in preparation for the recovery of bone mass after weaning. These data also demonstrate that maternal bone loss is not absolutely required to supply calcium for milk production unless dietary calcium intake is inadequate.
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Affiliation(s)
- Laleh Ardeshirpour
- Section of Endocrinology (L.A.), Department of Pediatrics, and Section of Endocrinology and Metabolism (C.D., P.D., J.S., J.V., W.K., J.W.), Department of Medicine, Yale University School of Medicine, New Haven, Connecticut 06520; and Department of Metabolic Disorders (P.K.), Amgen, Inc, Thousand Oaks, California 91320
| | - Cristina Dumitru
- Section of Endocrinology (L.A.), Department of Pediatrics, and Section of Endocrinology and Metabolism (C.D., P.D., J.S., J.V., W.K., J.W.), Department of Medicine, Yale University School of Medicine, New Haven, Connecticut 06520; and Department of Metabolic Disorders (P.K.), Amgen, Inc, Thousand Oaks, California 91320
| | - Pamela Dann
- Section of Endocrinology (L.A.), Department of Pediatrics, and Section of Endocrinology and Metabolism (C.D., P.D., J.S., J.V., W.K., J.W.), Department of Medicine, Yale University School of Medicine, New Haven, Connecticut 06520; and Department of Metabolic Disorders (P.K.), Amgen, Inc, Thousand Oaks, California 91320
| | - John Sterpka
- Section of Endocrinology (L.A.), Department of Pediatrics, and Section of Endocrinology and Metabolism (C.D., P.D., J.S., J.V., W.K., J.W.), Department of Medicine, Yale University School of Medicine, New Haven, Connecticut 06520; and Department of Metabolic Disorders (P.K.), Amgen, Inc, Thousand Oaks, California 91320
| | - Joshua VanHouten
- Section of Endocrinology (L.A.), Department of Pediatrics, and Section of Endocrinology and Metabolism (C.D., P.D., J.S., J.V., W.K., J.W.), Department of Medicine, Yale University School of Medicine, New Haven, Connecticut 06520; and Department of Metabolic Disorders (P.K.), Amgen, Inc, Thousand Oaks, California 91320
| | - Wonnam Kim
- Section of Endocrinology (L.A.), Department of Pediatrics, and Section of Endocrinology and Metabolism (C.D., P.D., J.S., J.V., W.K., J.W.), Department of Medicine, Yale University School of Medicine, New Haven, Connecticut 06520; and Department of Metabolic Disorders (P.K.), Amgen, Inc, Thousand Oaks, California 91320
| | - Paul Kostenuik
- Section of Endocrinology (L.A.), Department of Pediatrics, and Section of Endocrinology and Metabolism (C.D., P.D., J.S., J.V., W.K., J.W.), Department of Medicine, Yale University School of Medicine, New Haven, Connecticut 06520; and Department of Metabolic Disorders (P.K.), Amgen, Inc, Thousand Oaks, California 91320
| | - John Wysolmerski
- Section of Endocrinology (L.A.), Department of Pediatrics, and Section of Endocrinology and Metabolism (C.D., P.D., J.S., J.V., W.K., J.W.), Department of Medicine, Yale University School of Medicine, New Haven, Connecticut 06520; and Department of Metabolic Disorders (P.K.), Amgen, Inc, Thousand Oaks, California 91320
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16
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Onal M, Bishop KA, St John HC, Danielson AL, Riley EM, Piemontese M, Xiong J, Goellner JJ, O'Brien CA, Pike JW. A DNA segment spanning the mouse Tnfsf11 transcription unit and its upstream regulatory domain rescues the pleiotropic biologic phenotype of the RANKL null mouse. J Bone Miner Res 2015; 30:855-68. [PMID: 25431114 PMCID: PMC5240630 DOI: 10.1002/jbmr.2417] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/20/2014] [Revised: 11/15/2014] [Accepted: 11/24/2014] [Indexed: 12/26/2022]
Abstract
Receptor activator of NF-κB ligand (RANKL) is a TNFα-like cytokine that is produced by a diverse set of lineage-specific cells and is involved in a wide variety of physiological processes that include skeletal remodeling, lymph node organogenesis, mammary gland development, and thermal regulation. Consistent with these diverse functions, control of RANKL expression is accomplished in a cell-specific fashion via a set of at least 10 regulatory enhancers that are located up to 170 kb upstream of the gene's transcriptional start site. Here we examined the in vivo consequence of introducing a contiguous DNA segment containing these components into a genetically deleted RANKL null mouse strain. In contrast to RANKL null littermates, null mice containing the transgene exhibited normalized body size, skeletal development, and bone mass as well as normal bone marrow cavities, normalized spleen weights, and the presence of developed lymph nodes. These mice also manifested normalized reproductive capacity, including the ability to lactate and to produce normal healthy litters. Consistent with this, the transgene restored endogenous-like RANKL transcript levels in several RANKL-expressing tissues. Most importantly, restoration of RANKL expression from this segment of DNA was fully capable of rescuing the complex aberrant skeletal and immune phenotype of the RANKL null mouse. RANKL also restored appropriate levels of B220+ IgM+ and B220+ IgD+ B cells in spleen. Finally, we found that RANKL expression from this transgene was regulated by exogenously administered 1,25(OH)2 D3 , parathyroid hormone (PTH), and lipopolysaccharide (LPS), thus recapitulating the ability of these same factors to regulate the endogenous gene. These findings fully highlight the properties of the Tnfsf11 gene locus predicted through previous in vitro dissection. We conclude that the mouse Tnfsf11 gene locus identified originally through unbiased chromatin immunoprecipitation with DNA microarray (ChIP-chip) analysis contains the necessary genetic information to direct appropriate tissue-specific and factor-regulated RANKL expression in vivo.
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Affiliation(s)
- Melda Onal
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI, USA
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17
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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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18
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Ben-awadh AN, Delgado-Calle J, Tu X, Kuhlenschmidt K, Allen MR, Plotkin LI, Bellido T. Parathyroid hormone receptor signaling induces bone resorption in the adult skeleton by directly regulating the RANKL gene in osteocytes. Endocrinology 2014; 155:2797-809. [PMID: 24877630 PMCID: PMC4098003 DOI: 10.1210/en.2014-1046] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
PTH upregulates the expression of the receptor activator of nuclear factor κB ligand (Rankl) in cells of the osteoblastic lineage, but the precise differentiation stage of the PTH target cell responsible for RANKL-mediated stimulation of bone resorption remains undefined. We report that constitutive activation of PTH receptor signaling only in osteocytes in transgenic mice (DMP1-caPTHR1) was sufficient to increase Rankl expression and bone resorption. Resorption in DMP1-caPTHR1 mice crossed with mice lacking the distal control region regulated by PTH in the Rankl gene (DCR(-/-)) was similar to DMP1-caPTHR1 mice at 1 month of age, but progressively declined to reach values undistinguishable from wild-type (WT) mice at 5 months of age. Moreover, DMP1-caPTHR1 mice exhibited low tissue material density and increased serum alkaline phosphatase activity at 5 month of age, and these indices of high remodeling were partially and totally corrected in compound DMP1-caPTHR1;DCR(-/-) male mice, and less affected in female mice. Rankl expression in bones from DMP1-caPTHR1 mice was elevated at both 1 and 5 months of age, whereas it was high, similar to DMP1-caPTHR1 mice at 1 month, but low, similar to WT levels at 5 months in compound mice. Moreover, PTH increased Rankl and decreased Sost and Opg expression in ex vivo bone organ cultures established from WT mice, but only regulated Sost and Opg expression in cultures from DCR(-/-) mice. PTH also increased RANKL expression in osteocyte-containing primary cultures of calvarial cells, in isolated murine osteocytes, and in WT but not in DCR(-/-) osteocyte-enriched bones. Thus, PTH upregulates Rankl expression in osteocytes in vitro, ex vivo and in vivo, and resorption induced by PTH receptor signaling in the adult skeleton requires direct regulation of the Rankl gene in osteocytes.
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Affiliation(s)
- Abdullah N Ben-awadh
- Departments of Anatomy and Cell Biology (A.N.B., J.D.-C., X.T., K.K., M.R.A., L.I.P., T.B.) and Medicine (T.B.), Division of Endocrinology, Indiana University School of Medicine, and Roudebush Veterans Administration Medical Center (J.D.-C., L.I.P., T.B.), Indianapolis, Indiana 46202
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19
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St John HC, Bishop KA, Meyer MB, Benkusky NA, Leng N, Kendziorski C, Bonewald LF, Pike JW. The osteoblast to osteocyte transition: epigenetic changes and response to the vitamin D3 hormone. Mol Endocrinol 2014; 28:1150-65. [PMID: 24877565 DOI: 10.1210/me.2014-1091] [Citation(s) in RCA: 82] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Osteocytes are derived from osteoblast lineage cells that become progressively embedded in mineralized bone. Development of the osteocytogenic cell line IDG-SW3 has enabled a temporal and mechanistic investigation of this process. Through RNA-sequencing analyses, we show that although substantial changes in gene expression occur during the osteoblast to osteocyte transition, the majority of the transcriptome remains qualitatively osteoblast like. Genes either up-regulated or expressed uniquely in the osteocyte include local and systemic factors such as Sost and Fgf23 as well as genes implicated in neuronal, muscle, vascular, or regulatory function. As assessed by chromatin immunoprecipitation coupled to high-throughput sequencing, numerous changes in epigenetic histone modifications also occur during osteocytogenesis; these are largely qualitative rather than quantitative. Specific epigenetic changes correlate with altered gene expression patterns that are observed during the transition. These genomic changes likely influence the highly restricted transcriptomic response to 1,25(OH)(2)D(3) that occurs during differentiation. VDR binding in osteocytes revealed an extensive cistrome co-occupied by retinoid X receptor and located predominantly at sites distal to regulated genes. Although sites of VDR binding were apparent near many 1,25(OH)(2)D(3)-regulated genes, the expression of others adjacent to VDR-binding sites were unaffected; lack of VDR binding was particularly prevalent at down-regulated genes. Interestingly, 1,25(OH)(2)D(3) was found to induce the Boc and Cdon coreceptors that are active in hedgehog signaling in osteocytes. We conclude that osteocytogenesis is accompanied by changes in gene expression that may be driven by both genetic and epigenetic components. These changes are likely responsible for the osteocyte phenotype and may contribute to reduced sensitivity to 1,25(OH)(2)D(3).
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Affiliation(s)
- Hillary C St John
- Department of Biochemistry (H.C.S., K.A.B., M.B.M., N.A.B., J.W.P.) and Department of Biostatistics (N.L., C.K.), University of Wisconsin-Madison, Madison, Wisconsin 53706; and Department of Oral Biology (L.F.B.), School of Dentistry, University of Missouri, Kansas City, Missouri 6410
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20
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Modulatory effect of 1,25-dihydroxyvitamin D 3 on IL1 β -induced RANKL, OPG, TNF α , and IL-6 expression in human rheumatoid synoviocyte MH7A. Clin Dev Immunol 2013; 2013:160123. [PMID: 24348674 PMCID: PMC3855937 DOI: 10.1155/2013/160123] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2013] [Revised: 10/15/2013] [Accepted: 10/18/2013] [Indexed: 01/09/2023]
Abstract
Receptor activator of nuclear factor κB ligand (RANKL) plays a crucial role in the bone erosion of rheumatoid arthritis (RA) by prompting osteoclastogenesis. Considering that 1,25(OH)2D3 has been suggested as a potent inducer of RANKL expression, it should clarify whether vitamin D supplement could result in RANKL overexpression and thereby facilitate excessive osteoclastogenesis and bone resorption in RA. Here, we investigated modulatory effect of 1,25(OH)2D3 on the expression of RANKL and its decoy receptor osteoprotegerin (OPG) in an inflammatory condition of human rheumatoid synoviocyte MH7A. MH7A cells were stimulated with IL1β and then treated with different concentrations of 1,25(OH)2D3 for 48 h. A significantly elevated OPG/RANKL ratio and markedly decreased levels of IL-6 and TNFβ mRNA expression in cells and IL-6 protein in supernatants were observed in IL1β-induced MH7A in the presence of 1,25(OH)2D3 compared with those in the absence of it. Osteoclast formation was obviously decreased when RAW264.7 cells were treated with both 1,25(OH)2D3 and IL1β. In summary, although it has a biological function to induce RANKL expression, 1,25(OH)2D3 could upregulate OPG/RANKL ratio and mediate anti-inflammatory action in an inflammatory milieu of synoviocyte, contributing to the inhibition of inflammation-induced osteoclastogenesis in RA.
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21
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O’Brien CA, Nakashima T, Takayanagi H. Osteocyte control of osteoclastogenesis. Bone 2013; 54:258-63. [PMID: 22939943 PMCID: PMC3538915 DOI: 10.1016/j.bone.2012.08.121] [Citation(s) in RCA: 166] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/15/2012] [Revised: 08/01/2012] [Accepted: 08/11/2012] [Indexed: 01/16/2023]
Abstract
Multiple lines of evidence support the idea that osteocytes act as mechanosensors in bone and that they control bone formation, in part, by expressing the Wnt antagonist sclerostin. However, the role of osteocytes in the control of bone resorption has been less clear. Recent studies have demonstrated that osteocytes are the major source of the cytokine RANKL involved in osteoclast formation in cancellous bone. The goal of this review is to discuss these and other studies that reveal mechanisms whereby osteocytes control osteoclast formation and thus bone resorption.
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Affiliation(s)
- Charles A. O’Brien
- Division of Endocrinology and Metabolism, Center for Osteoporosis and Metabolic Bone Diseases, University of Arkansas for Medical Sciences and the Central Arkansas Veterans Healthcare System, Little Rock, AR 72205
| | - Tomoki Nakashima
- Department of Cell Signaling, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Yushima 1–5–45, Bunkyo-ku, Tokyo 113–8549, Japan
- Japan Science and Technology Agency (JST), Explorative Research for Advanced Technology (ERATO) Program, Takayanagi Osteonetwork Project, Hongo 7–3–1, Bunkyo-ku, Tokyo 113–0033, Japan
| | - Hiroshi Takayanagi
- Department of Cell Signaling, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Yushima 1–5–45, Bunkyo-ku, Tokyo 113–8549, Japan
- Japan Science and Technology Agency (JST), Explorative Research for Advanced Technology (ERATO) Program, Takayanagi Osteonetwork Project, Hongo 7–3–1, Bunkyo-ku, Tokyo 113–0033, Japan
- 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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22
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Sundaram K, Rao DS, Ries WL, Reddy SV. CXCL5 stimulation of RANK ligand expression in Paget's disease of bone. J Transl Med 2013; 93:472-9. [PMID: 23439434 DOI: 10.1038/labinvest.2013.5] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Paget's disease of bone (PDB) is a chronic focal skeletal disorder that affects 2-3% of the population over 55 years of age. PDB is marked by highly localized areas of bone turnover with increased osteoclast activity. Evidence suggests a functional role for measles virus nucleocapsid protein (MVNP) in the pathogenesis of PDB. In the present study, we identified elevated levels (≈ 180-fold) of CXCL5 mRNA expression in bone marrow cells from patients with PDB compared with that in normal subjects. In addition, CXCL5 levels are increased (five-fold) in serum samples from patients with PDB. Furthermore, MVNP transduction in human bone marrow monocytes significantly increased CXCL5 mRNA expression. Real-time PCR analysis showed that CXCL5 stimulation increased (6.8-fold) RANKL mRNA expression in normal human bone marrow-derived stromal (SAKA-T) cells. Moreover, CXCL5 increased (5.2-fold) CXCR1 receptor expression in these cells. We further showed that CXCL5 treatment elevated the expression levels of phospho-ERK1/2 and phospho-p38. CXCL5 also significantly increased phosphorylation of CREB (cAMP response element-binding) in bone marrow stromal/preosteoblast cells. Chromatin immuneprecipitation (ChIP) assay confirmed phospho-CREB binding to RANKL gene promoter region. Further, the suppression of p-CREB expression by the inhibitors of ERK1/2, p38 and PKA significantly decreased CXCL5 stimulation of hRANKL gene promoter activity. Thus, our results suggest that CREB is a downstream effector of CXCL5 signaling and that increased levels of CXCL5 contribute to enhanced levels of RANKL expression in PDB.
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Affiliation(s)
- Kumaran Sundaram
- Charles P Darby Children's Research Institute, Charleston, SC 29425, USA
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