scholarly journals IL-1β Suppresses the Formation of Osteoclasts by Increasing OPG Production via an Autocrine Mechanism Involving Celecoxib-Related Prostaglandins in Chondrocytes

2009 ◽  
Vol 2009 ◽  
pp. 1-9 ◽  
Author(s):  
Yusuke Watanabe ◽  
Aki Namba ◽  
Yukiko Aida ◽  
Kazuhiro Honda ◽  
Hideki Tanaka ◽  
...  

Elevated interleukin (IL)-1 concentrations in synovial fluid have been implicated in joint bone and cartilage destruction. Previously, we showed that IL-1βstimulated the expression of prostaglandin (PG) receptor EP4 via increasedPGE2production. However, the effect of IL-1βon osteoclast formation via chondrocytes is unclear. Therefore, we examined the effect of IL-1βand/or celecoxib on the expression of macrophage colony-stimulating factor (M-CSF), receptor activator of NF-κB ligand (RANKL), and osteoprotegerin (OPG) in human chondrocytes, and the indirect effect of IL-1βon osteoclast-like cell formation using RAW264.7 cells. OPG and RANKL expression increased with IL-1β; whereas M-CSF expression decreased. Celecoxib blocked the stimulatory effect of IL-1β. Conditioned medium from IL-1β-treated chondrocytes decreased TRAP staining in RAW264.7 cells. These results suggest that IL-1βsuppresses the formation of osteoclast-like cells via increased OPG production and decreased M-CSF production in chondrocytes, and OPG production may increase through an autocrine mechanism involving celecoxib-related PGs.

2005 ◽  
Vol 280 (16) ◽  
pp. 16163-16169 ◽  
Author(s):  
Michael S. Kim ◽  
Christopher J. Day ◽  
Nigel A. Morrison

Human osteoclast formation from monocyte precursors under the action of receptor activator of nuclear factor-κB ligand (RANKL) was suppressed by granulocyte macrophage colony-stimulating factor (GM-CSF), with down-regulation of critical osteoclast-related nuclear factors. GM-CSF in the presence of RANKL and macrophage colony-stimulating factor resulted in mononuclear cells that were negative for tartrate-resistant acid phosphatase (TRAP) and negative for bone resorption. CD1a, a dendritic cell marker, was expressed in GM-CSF, RANKL, and macrophage colony-stimulating factor-treated cells and absent in osteoclasts. Microarray showed that the CC chemokine, monocyte chemotactic protein 1 (MCP-1), was profoundly repressed by GM-CSF. Addition of MCP-1 reversed GM-CSF suppression of osteoclast formation, recovering the bone resorption phenotype. MCP-1 and chemokine RANTES (regulated on activation normal T cell expressed and secreted) permitted formation of TRAP-positive multinuclear cells in the absence of RANKL. However, these cells were negative for bone resorption. In the presence of RANKL, MCP-1 significantly increased the number of TRAP-positive multinuclear bone-resorbing osteoclasts (p= 0.008). When RANKL signaling through NFATc1 was blocked with cyclosporin A, both MCP-1 and RANTES expression was down-regulated. Furthermore, addition of MCP-1 and RANTES reversed the effects of cyclosporin A and recovered the TRAP-positive multinuclear cell phenotype. Our model suggests that RANKL-induced chemokines are involved in osteoclast differentiation at the stage of multinucleation of osteoclast precursors and provides a rationale for increased osteoclast activity in inflammatory conditions where chemokines are abundant.


Endocrinology ◽  
2011 ◽  
Vol 152 (5) ◽  
pp. 1911-1922 ◽  
Author(s):  
Hasnawati Saleh ◽  
Damien Eeles ◽  
Jason M. Hodge ◽  
Geoffrey C. Nicholson ◽  
Ran Gu ◽  
...  

IL-33 is an important inflammatory mediator in allergy, asthma, and joint inflammation, acting via its receptor, ST2L, to elicit Th2 cell cytokine secretion. IL-33 is related to IL-1 and IL-18, which both influence bone metabolism, IL-18 in particular inhibiting osteoclast formation and contributing to PTH bone anabolic actions. We found IL-33 immunostaining in osteoblasts in mouse bone and IL-33 mRNA expression in cultured calvarial osteoblasts, which was elevated by treatment with the bone anabolic factors oncostatin M and PTH. IL-33 treatment strongly inhibited osteoclast formation in bone marrow and spleen cell cultures but had no effect on osteoclast formation in receptor activator of nuclear factor-κB ligand/macrophage colony-stimulating factor-treated bone marrow macrophage (BMM) or RAW264.7 cultures, suggesting a lack of direct action on immature osteoclast progenitors. However, osteoclast formation from BMM was inhibited by IL-33 in the presence of osteoblasts, T cells, or mature macrophages, suggesting these cell types may mediate some actions of IL-33. In bone marrow cultures, IL-33 induced mRNA expression of granulocyte macrophage colony-stimulating factor, IL-4, IL-13, and IL-10; osteoclast inhibitory actions of IL-33 were rescued only by combined antibody ablation of these factors. In contrast to osteoclasts, IL-33 promoted matrix mineral deposition by long-term ascorbate treated primary osteoblasts and reduced sclerostin mRNA levels in such cultures after 6 and 24 h of treatment; sclerostin mRNA was also suppressed in IL-33-treated calvarial organ cultures. In summary, IL-33 stimulates osteoblastic function in vitro but inhibits osteoclast formation through at least three separate mechanisms. Autocrine and paracrine actions of osteoblast IL-33 may thus influence bone metabolism.


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