scholarly journals Targeted Deletion of a Distant Transcriptional Enhancer of the Receptor Activator of Nuclear Factor-κB Ligand Gene Reduces Bone Remodeling and Increases Bone Mass

Endocrinology ◽  
2007 ◽  
Vol 149 (1) ◽  
pp. 146-153 ◽  
Author(s):  
Carlo Galli ◽  
Lee A. Zella ◽  
Jackie A. Fretz ◽  
Qiang Fu ◽  
J. Wesley Pike ◽  
...  
Keyword(s):  
Bone Mass ◽  
Bone Remodeling ◽  
Nuclear Factor Κb ◽  
Nuclear Factor ◽  
Rankl Expression ◽  
Transcriptional Enhancer ◽  
Dihydroxyvitamin D3 ◽  
Rankl Mrna ◽  
Receptor Activator ◽  
Stimulation Of

Receptor activator of nuclear factor-κB ligand (RANKL) is essential for osteoclast differentiation, and hormones and cytokines that stimulate bone resorption increase RANKL expression in stromal/osteoblastic cells. We have previously shown that PTH and 1,25-dihydroxyvitamin D3 control murine RANKL gene expression in vitro, in part, via an evolutionarily conserved transcriptional enhancer, designated the distal control region (DCR), located 76 kb upstream from the transcription start site. Herein we describe the phenotype of mice lacking this enhancer. Deletion of the DCR reduced PTH and 1,25-dihydroxyvitamin D3 stimulation of RANKL mRNA and osteoclast formation in primary bone marrow cultures as well as stimulation of RANKL mRNA in bone. DCR deletion also reduced basal RANKL mRNA levels in bone, thymus, and spleen. Moreover, mice lacking the DCR exhibited increased bone mass and strength. The increase in bone mass was due to reduced osteoclast and osteoblast formation leading to a low rate of bone remodeling similar to that observed in humans and mice with hypoparathyroidism. These findings demonstrate that hormonal control of RANKL expression via the DCR is a critical determinant of the rate of bone remodeling.

scholarly journals Colony-Stimulating Factor-1 (CSF-1) Directly Inhibits Receptor Activator of Nuclear Factor-κB Ligand (RANKL) Expression by Osteoblasts

Endocrinology ◽  
2009 ◽  
Vol 150 (11) ◽  
pp. 4977-4988 ◽  
Author(s):  
Y. Wittrant ◽  
Y. Gorin ◽  
S. Mohan ◽  
B. Wagner ◽  
S. L. Abboud-Werner
Keyword(s):  
Nuclear Factor Κb ◽  
Nuclear Factor ◽  
Colony Stimulating Factor ◽  
Wild Type ◽  
Rankl Expression ◽  
Nadph Oxidase Activity ◽  
Rankl Mrna ◽  
Receptor Activator ◽  
Bone Marrow Cultures ◽  
Stimulating Factor

Colony-stimulating factor-1 (CSF-1), released by osteoblasts, stimulates the proliferation of osteoclast progenitors via the c-fms receptor (CSF-1R) and, in combination with receptor activator of nuclear factor-κB ligand (RANKL), leads to the formation of mature osteoclasts. Whether the CSF-1R is expressed by osteoblasts and mediates specific biological effects in osteoblasts has not been explored. Wild-type primary calvaria osteoblasts (OB) were analyzed for CSF-1R expression (RT-PCR and Western blot) and functionality (immunocomplex kinase assay). OB were serum starved for 24 h, and the effect of CSF-1 (0–100 ng/ml) on OB biological activities was determined at 48 h. In wild-type mouse bone marrow cultures, CSF-1 was tested for its effect on RANKL mRNA and osteoclast formation. Because ROS influence osteoblast RANKL expression, studies analyzed the effect of CSF-1 on reduced nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activity and Nox1 and Nox4 proteins. Results indicate that OB express CSF-1R mRNA and protein and that CSF-1R could be phosphorylated in the presence of CSF-1. In osteoblasts, CSF-1 decreased RANKL mRNA in a dose- and time-dependent manner. Incubation of bone marrow cultures with CSF-1 resulted in a significant decline in tartrate-resistant acid phosphatase (TRACP) activity and CTR expression. RANKL-decreased expression by CSF-1 was correlated with a decrease of NADPH oxidase activity as well as Nox1 and Nox4 protein levels. These findings provide the first evidence that osteoblasts express CSF-1R and are a target for CSF-1 ligand. CSF-1-mediated inhibition of RANKL expression on osteoblasts may provide an important mechanism for coupling bone formation/resorption and preventing excessive osteoclastogenesis during normal skeletal growth.

Rituximab abrogates joint destruction in rheumatoid arthritis by inhibiting osteoclastogenesis

2011 ◽  
Vol 71 (1) ◽  
pp. 108-113 ◽  
Author(s):  
Maria J H Boumans ◽  
Rogier M Thurlings ◽  
Lorraine Yeo ◽  
Dagmar Scheel-Toellner ◽  
Koen Vos ◽  
...  
Keyword(s):  
Rheumatoid Arthritis ◽  
Joint Destruction ◽  
Bone Destruction ◽  
Nuclear Factor Κb ◽  
Type I ◽  
Nuclear Factor ◽  
Rankl Expression ◽  
Osteoclast Precursors ◽  
Receptor Activator ◽  
Hands And Feet

ObjectivesTo examine how rituximab may result in the inhibition of joint destruction in rheumatoid arthritis (RA) patients.MethodsTwenty-eight patients with active RA were treated with rituximab. Radiographs of hands and feet before and 1 year after therapy were assessed using the Sharp–van der Heijde score (SHS). Expression of bone destruction markers was evaluated by immunohistochemistry and immunofluorescence of synovial biopsies obtained before and 16 weeks after the initiation of treatment. Serum levels of osteoprotegerin, receptor activator of nuclear factor κB ligand (RANKL), osteocalcin and cross-linked N-telopeptides of type I collagen (NTx) were measured by ELISA before and 16 weeks post-treatment.ResultsAfter 1 year, the mean (SD) change in total SHS was 1.4 (10.0). Sixteen weeks after treatment there was a decrease of 99% in receptor activator of nuclear factor κB-positive osteoclast precursors (p=0.02) and a decrease of 37% (p=0.016) in RANKL expression in the synovium and a trend towards reduced synovial osteoprotegerin expression (25%, p=0.07). In serum, both osteoprotegerin (20%, p=0.001) and RANKL (40%, p<0.0001) levels were significantly reduced 16 weeks after treatment, but the osteoprotegerin/RANKL ratio increased (157%, p=0.006). A trend was found towards an increase of osteocalcin levels (p=0.053), while NTx concentrations did not change.ConclusionsRituximab treatment is associated with a decrease in synovial osteoclast precursors and RANKL expression and an increase in the osteoprotegerin/RANKL ratio in serum. These observations may partly explain the protective effect of rituximab on the progression of joint destruction in RA.

scholarly journals Absence of Herpes Virus Entry Mediator (HVEM) Increases Bone Mass by Attenuating Receptor Activator of Nuclear Factor-κB ligand (RANKL)-Induced Osteoclastogenesis

Endocrinology ◽  
2012 ◽  
Vol 153 (10) ◽  
pp. 4808-4817 ◽  
Author(s):  
Woon-Ki Kim ◽  
Ok-Joo Sul ◽  
Eun-Kyung Choi ◽  
Mi-Hyun Lee ◽  
Choon-Soo Jeong ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Bone Mass ◽  
Knockout Mice ◽  
Herpes Virus ◽  
Virus Entry ◽  
Nuclear Factor Κb ◽  
Nuclear Factor ◽  
Herpes Virus Entry Mediator ◽  
Receptor Activator ◽  
Herpès Virus

Abstract Herpes virus entry mediator (HVEM), which is constitutively expressed at a high level on myeloid lineage cells, is also expressed on bone marrow-derived macrophages, suggesting that it may play a role in bone metabolism by affecting osteoclasts (OC) derived from bone marrow-derived macrophages. To address this question, we evaluated bone mass by micro-computed tomography and the number and activity of OC by tartrate-resistant acid phosphatase (TRAP) and pit formation on dentine slices, comparing HVEM-knockout mice with wild-type mice. The absence of HVEM led to a higher bone mass and to decreased levels of serum collagen type I fragments and serum TRACP5b in vivo. In vitro HVEM deficiency resulted in a reduced number and activity of OC and an impaired receptor activator of nuclear factor-κB ligand signaling through reduced activation of nuclear factor-κB and of nuclear factor of activated T-cells cytoplasmic 1. Exogenous soluble HVEM decreased expression of TRAP, whereas soluble LIGHT (a ligand of HVEM) increased it, indicating the occurrence of a positive signaling through HVEM during osteoclastogenesis. Our findings indicate that HVEM regulates bone remodeling via action on OC. The higher bone mass in the femurs of HVEM-knockout mice could be, at least in part, due to attenuated osteoclastogenesis and bone resorption resulting from decreased receptor activator of nuclear factor-κB ligand signaling in the OC.

scholarly journals Role of Prostaglandin E in Receptor Activator of Nuclear Factor-κB Ligand (RANKL) Expression in Osteoblasts Induced by Cell Adhesion to Bone Marrow B-lymphocytes

2009 ◽  
Vol 55 (5) ◽  
pp. 832-837 ◽  
Author(s):  
Michiko Hirata ◽  
Suguru Harada ◽  
Chiho Matsumoto ◽  
Morichika Takita ◽  
Chisato Miyaura ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Cell Adhesion ◽  
B Lymphocytes ◽  
Nuclear Factor Κb ◽  
Prostaglandin E ◽  
Nuclear Factor ◽  
Rankl Expression ◽  
Receptor Activator

scholarly journals The Fungal Metabolite (+)-Terrein Abrogates Ovariectomy-Induced Bone Loss and Receptor Activator of Nuclear Factor-κB Ligand–Induced Osteoclastogenesis by Suppressing Protein Kinase-C α/βII Phosphorylation

2021 ◽  
Vol 12 ◽  
Author(s):  
Kyosuke Sakaida ◽  
Kazuhiro Omori ◽  
Masaaki Nakayama ◽  
Hiroki Mandai ◽  
Saki Nakagawa ◽  
...  
Keyword(s):  
Bone Loss ◽  
Bone Mass ◽  
Bone Metabolism ◽  
Osteoclast Differentiation ◽  
Nuclear Factor Κb ◽  
Common Disease ◽  
Mouse Bone Marrow ◽  
Nuclear Factor ◽  
Receptor Activator

Osteoporosis is a common disease characterized by a systemic impairment of bone mass and microarchitecture that results in fragility fractures. Severe bone loss due to osteoporosis triggers pathological fractures and consequently decreases the daily life activity and quality of life. Therefore, prevention of osteoporosis has become an important issue to be addressed. We have reported that the fungal secondary metabolite (+)-terrein (TER), a natural compound derived from Aspergillus terreus, has shown receptor activator of nuclear factor-κB ligand (RANKL)–induced osteoclast differentiation by suppressing nuclear factor of activated T-cell 1 (NFATc1) expression, a master regulator of osteoclastogenesis. TER has been shown to possess extensive biological and pharmacological benefits; however, its effects on bone metabolism remain unclear. In this study, we investigated the effects of TER on the femoral bone metabolism using a mouse-ovariectomized osteoporosis model (OVX mice) and then on RANKL signal transduction using mouse bone marrow macrophages (mBMMs). In vivo administration of TER significantly improved bone density, bone mass, and trabecular number in OVX mice (p &lt; 0.01). In addition, TER suppressed TRAP and cathepsin-K expression in the tissue sections of OVX mice (p &lt; 0.01). In an in vitro study, TER suppressed RANKL-induced phosphorylation of PKCα/βII, which is involved in the expression of NFATc1 (p &lt; 0.05). The PKC inhibitor, GF109203X, also inhibited RANKL-induced osteoclastogenesis in mBMMs as well as TER. In addition, TER suppressed the expression of osteoclastogenesis-related genes, such as Ocstamp, Dcstamp, Calcr, Atp6v0d2, Oscar, and Itgb3 (p &lt; 0.01). These results provide promising evidence for the potential therapeutic application of TER as a novel treatment compound against osteoporosis.

scholarly journals Triiodothyronine (T3) does not induce Rankl expression in rat Ros 17/2.8 cells

2008 ◽  
Vol 52 (1) ◽  
pp. 109-113 ◽  
Author(s):  
Patrícia P. Saraiva ◽  
Silvania S. Teixeira ◽  
Célia Regina Nogueira ◽  
Carlos Roberto Padovani
Keyword(s):  
Messenger Rna ◽  
Nuclear Factor Kappa B ◽  
Osteoclast Differentiation ◽  
Hormone Treatment ◽  
Nuclear Factor ◽  
Rankl Expression ◽  
Loss Mechanism ◽  
Nuclear Factor Kappa ◽  
Rankl Mrna ◽  
Receptor Activator

Osteoclastogenesis may be regulated via activation of the RANK/RANKL (receptor activator of nuclear factor-kappa B/ receptor activator of nuclear factor-kappa B ligand) system, which is mediated by osteoblasts. However, the bone loss mechanism induced by T3 (triiodothyronine) is still controversial. In this study, osteoblastic lineage rat cells (ROS 17/2.8) were treated with T3 (10-8 M, 10-9 M, and 10-10 M), and RANKL mRNA (messenger RNA) expression was measured by semiquantitative RT-PCR. Our results show that T3 concentrations used did not significantly enhance RANKL expression compared to controls without hormone treatment. This data suggests that other mechanisms, unrelated to the RANK/RANKL system, might be to activate osteoclast differentiation in these cells.

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