• Molecules and Cells
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• 제40권5호
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• pp.371-377
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• 2017

Despite the importance of the receptor activator of nuclear factor (NF)-kappaB ligand (RANKL)-RANK signaling mechanisms on osteoclast differentiation, little has been studied on how RANK expression is regulated or what regulates its expression during osteoclastogenesis. We show here that insulin signaling increases RANK expression, thus enhancing osteoclast differentiation by RANKL. Insulin stimulation induced RANK gene expression in time- and dose-dependent manners and insulin receptor shRNA completely abolished RANK expression induced by insulin in bone marrow-derived monocyte/macrophage cells (BMMs). Moreover, the addition of insulin in the presence of RANKL promoted RANK expression. The ability of insulin to regulate RANK expression depends on extracellular signal-regulated kinase 1/2 (ERK1/2) since only PD98059, an ERK1/2 inhibitor, specifically inhibited its expression by insulin. However, the RANK expression by RANKL was blocked by all three mitogen-activated protein (MAP) kinases inhibitors. The activation of RANK increased differentiation of BMMs into tartrate-resistant acid phosphatase-positive ($TRAP^+$) osteoclasts as well as the expression of dendritic cell-specific transmembrane protein (DC-STAMP) and d2 isoform of vacuolar ($H^+$) ATPase (v-ATPase) Vo domain (Atp6v0d2), genes critical for osteoclastic cell-cell fusion. Collectively, these results suggest that insulin induces RANK expression via ERK1/2, which contributes to the enhancement of osteoclast differentiation.

• 동의생리병리학회지
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• 제22권4호
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• pp.891-895
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• 2008

Natural substances have recently received much attention as therapeutic drugs to prevent many diseases in humans because they avoid the many side effects of treatment with chemical compounds. We examined the effect of water extract of deer antler in RANKL-induced osteoclast differentiation. The effects of water extract of deer antler in osteoclast differentiation were determined by culture of bone marrow macrophages (BMMs). The mRNA expression levels of c-Fos, NFATc1, TRAP, and GAPDH in BMMs were analyzed by RT-PCR. Cell lysates were obtained from the treated cells, the expression levels of c-Fos and NFATc1 were determined by western blotting with antibodies for c-Fos and NFATc1. Water extract of deer antler greatly inhibited RANKL-mediated osteoclast differentiation in osteoclast precursors without cytotoxicity. Water extract of deer antler inhibited the expression of c-Fos and NFATc1 in BMMs treated with RANKL. Our findings suggest that water extract of deer antler inhibited osteoclast differentiation by suppressing c-Fos and NFATc1 expression in response to RANKL. These results demonstrate that water extract of deer antler may be a useful the treatment of bone-related disease such as osteoporosis.

• Journal of Periodontal and Implant Science
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• 제32권4호
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• pp.721-731
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• 2002

Recently, soluble TNF receptor homolog osteoprotegerin(OPG) and its membrane-bound ligand osteoclast differentiation factor(ODF) were found to regulate osteoclast formation and function, and bone metabolism. It is now well established that ODF acts via RANK expressed on hematopoietic osteoclast precursor cells to facilitate their differentiation to osteoclasts, and OPG prevents the formation of osteoclasts by interfering the binding of ODF and RANK. Expression of OPG and ODF was believed to be closely related to the pathogenesis of bone resorption and destruction from osteoporosis, periodontal diseases, malignant bone tumor, and arthritis. The periodontal ligament fibroblasts (PDLF), located between the tooth and tooth socket, has been thought to play an important role in maintaining bone homeostasis of periodontal tissues. However, the exact mechanism by which bone formation and resorption are regulated by PDLF is not well understood. In this study we have prepared primary cultures of human PDLF from periodontium of malaligned tooth extracted due to orthodontic reason, and determined steady state or inflammatory signal-induced OPG and ODF expression using RT-PCR and western blot analysis. OPG and ODF mRNA and protein were expressed constitutively in the PDLF and these expression were slightly increased by osteotropic cytokine IL-1 ${\beta}$. Lipopolysaccharide-treated PDLF showed decrease in OPG mRNA and protein expression, and increase in ODF mRNA and protein expression. These results indicated that PDLF influence the osteoclastogenesis by OPG and ODF expression in the inflammatory situation as well as physiological condition, and thereby pathogenesis of periodontal alveolar bone destruction.

• International Journal of Oral Biology
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• 제45권1호
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• pp.15-24
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• 2020

The fruit of Chaenomeles sinensis (Thouin) Koehne (Chaenomelis Fructus) known as "Mo-Gua" in Korea has been commonly used in traditional medicine to treat inflammatory diseases, such as sore throat. However, its effect on bone metabolism has not been elucidated yet. Here, we examined the effect of Chaenomelis Fructus ethanol extract (CF-E) on receptor activator of nuclear factor (NF)-κB ligand (RANKL)-mediated osteoclast differentiation and formation. CF-E considerably inhibited osteoclast differentiation and tartrate-resistant acid phosphatase-positive multinuclear cell formation from bone marrow-derived macrophages and osteoclast precursor cells in a dose-dependent manner. In addition, the formation of actin rings and resorption pits were significantly suppressed in CF-E-treated osteoclasts as compared with the findings in non-treated control cells. Consistent with these phenotypic inhibitory results, the expressions of osteoclast differentiation marker genes (Acp5, Atp6v0d2, Oscar, CtsK, and Tm7sf4) and Nfatc1, a pivotal transcription factor for osteoclastogenesis, were markedly decreased by CF-E treatment. The inhibitory effect of CF-E on RANKL-induced osteoclastogenesis was associated with the suppression of NFATc1 expression, not by regulation of mitogen-activated protein kinases and NF-κB activation but by the inactivation of phospholipase C gamma 1 and 2. These results indicate that CF-E has an inhibitory effect on osteoclast differentiation and formation, and they suggest the possibility of CF-E as a traditional therapeutic agent against bone-resorptive diseases, such as osteoporosis, rheumatoid arthritis, and periodontitis.

• 동의생리병리학회지
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• 제24권1호
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• pp.74-79
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• 2010

Osteoclasts are bone-resorbing giant cells that differentiate from hematopoietic cells of the monocyte/macrophages. Excessive osteoclast differentiation leads to gradual loss of bone mass causing fracture of the skeleton. The aim of this study was to develop a drug candidates for the treatment of osteoporosis. RANKL-induced osteoclast differentiation was dose-dependently inhibited by myricetin. Myricetin inhibited the expression of c-Fos, NFATc1, and TRAP in BMMs treated with RANKL. Myricetin disrupted the structure of actin ring and suppressed osteoclastic bone resorption. Also, myricetin induced apoptosis in mature osteoclasts. Myricetin inhibited the phosphorylation of ERK in mature osteoclasts treated with M-CSF. The activation of caspase-9 and caspase-3 was increased by myricetin treatment. Our results suggest that myricetin may be an effective agent to prevent bone diseases such as osteoporosis.

• Journal of Periodontal and Implant Science
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• 제29권4호
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• pp.995-1005
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• 1999

Alveolar bone destruction is a character-istic of periodontal disease. Treponema denticola are found in significantly increased numbers in the sites affected with periodontal disease. In order to clarify the role of T. denticola in destruction of alveo-lar bone in periodontal disease, this study was undertaken to determine the effect of sonicated extract of T. denticola on osteo-clast differentiation in co-culture system of mouse bone marrow cells and calvaria cells. The ability of osteoclast formation was estimated by counting the number of tar-tartrate resistant acid phosphatase(TRAP) positive cells. Sonicated extract of this bacteria stimulated osteoclast formation in a dose dependent manner(p<0.05). Indomathacin, an inhibitor of prostaglandin synthesis, decreased osteoclast formation induced by sonicated extract of this bacte-bacteria(p<0.05). Extract-induced osteoclast formation was decreased, when sonicated extract of bacteria was heated(p<0.05). These findings suggest that T. denticola induces osteoclast differentiation, and protein component of this bacteria and $PGE_2$ may play an important role in this process.

• 동의생리병리학회지
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• 제25권1호
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• pp.109-114
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• 2011

Atractylodis Rhizoma Alba is commonly used herbal medicine and it has been known that has immuno-regualtory effects and anti-cancer effects. The inhibition of osteoclastogenesis is essential for the prevention and treatment of osteoporosis. The aim of this study was to evaluate the effects of Atractylodis Rhizoma Alba on osteoclast differentiation in vitro and on resorbing activity of osteoclast. Osteoclast formation was evaluated in bone marrow cells (BMC) in the presence or absence of Atractylodis Rhizoma Alba. The expression of c-fos, tartrate-resistant acid phosphatase (TRAP), OSCAR, DC-STAMP, cathepsin K, MafB and NFATc1 mRNA in osteoclast precursor were assessed by RT-PCR. The levels of TNF receptor-associated factor-6 (TRAF-6), c-fos and NFATc1 protein were assessed by Western blot analysis. Also the correlation with MAPKs and NF-${\kappa}B$ pathways were measured by using Western blot analysis. With bone resorption study, I tried to evaluate the inhibitory effects of Atractylodis Rhizoma Alba on mature osteoclast function. Atractylodis Rhizoma Alba inhibited the RANKL induced osteoclastic differentiation from bone marrow macrophage in a dose dependant manner without cellular toxicity. Gene expression of c-fos and NFATc1 was significantly down regulated with Atractylodis Rhizoma Alba treatment. Atractylodis Rhizoma Alba markedly inhibited the RANKL-induced osteoclastogenesis through suppression of nuclear factor kappa b (NF-${\kappa}B$) pathway, down stream pathway of p38, ERK and JNK pathway. Taken together, I concluded that Atractylodis Rhizoma Alba have beneficial effect on osteoporosis by inhibition of osteoclast differentiation and by inhibition of functioning osteoclast. Thus I expect that Atractylodis Rhizoma Alba could be a treatment option for osteoporosis.

• 동의생리병리학회지
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• 제27권4호
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• pp.431-436
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• 2013

Bone homeostasis is maintained by co-ordination of bone-resorbing osteoclasts and bone-forming osteoblasts. Imbalance between osteoclasts and osteoblasts leads to many bone diseases such as osteoporosis, rheumatoid arthritis. Taxillus chinensis is a herb that has been widely used to improve bone health. However, the effect and mechanism of Taxillus chinensis extract on osteoclast differentiation and bone resportion has been unknown. Thus, We investigated the effect of Taxillus chinensis on expression of receptor activator of nuclear factor-${\kappa}B$ ligand (RANKL)-induced osteoclast differentiation and bone resorption. Also, the action of Taxillus chinensis on mechanisms relating to osteoclast differentiation was studied. In this results, we identified that Taxillus chinensis significantly inhibited RANKL-induced osteoclast differentiation and bone resportion. Moreover, Taxillus chinensis was suppressed the activation of NF-${\kappa}B$ in bone marrow macrophage treated RANKL and M-CSF. Taxillus chinensis was down-regulated the mRNA expression of c-Fos, nuclear factor of activated T-cells (NFAT)c1, osteoclast-associated receptor (OSCAR), tartrate-resistant acid phosphatase (TRAP). The cell adhesion-related molecules such as integrin ${\alpha}v$ and integrin ${\beta}3$, and the filamentous actin (F-actin) rings of mature osteoclasts-related molecules such as dendritic cell-specific transmembrane preotein (DC-STAMP) and cathepsin K are also suppressed. Taken together, these results indicated that Taxillus chinensis will be a good candidate to treat osteoclast-mediated bone diseases.

• BMB Reports
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• 제50권3호
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• pp.150-155
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• 2017

Non-small-cell lung cancer (NSCLC) is the third most common cancer that spreads to the bone, resulting in osteolytic lesions caused by hyperactivation of osteoclasts. Activating mutations in epidermal growth factor receptor-tyrosine kinase (EGF-TK) are frequently associated with NSCLC, and afatinib is a first-line therapeutic drug, irreversibly targeting EGF-TK. However, the effects of afatinib on osteoclast differentiation and activation as well as the underlying mechanism remain unclear. In this study, afatinib significantly suppressed receptor activator of nuclear factor ${\kappa}B$ (RANK) ligand (RANKL)-induced osteoclast formation in bone marrow macrophages (BMMs). Consistently, afatinib inhibited the expression of osteoclast marker genes, whereas, it upregulated the expression of negative modulator genes. The bone resorbing activity of osteoclasts was also abrogated by afatinib. In addition, afatinib significantly inhibited RANKL-mediated Akt/protein kinase B and c-Jun N-terminal kinase phosphorylation. These results suggest that afatinib substantially suppresses osteoclastogenesis by downregulating RANK signaling pathways, and thus may reduce osteolysis after bone metastasis.

• 대한한방부인과학회지
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• 제25권3호
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• pp.16-26
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• 2012

Objectives: This study was performed to evaluate effects of Cordyceps militaris(CM) on osteoclast differentiation and its related gene expression. Methods: We used mouse myeloid cells RAW 264.7 stimulated by receptor activator of nuclear factor kappa-B ligand(RANKL) to induce osteoclast differentiation. There are four groups of which RAW 264.7 cells are not stimulated by RANKL (Normal), stimulated by RANKL without CM(Control), stimulated by RANKL with 0.1 ${\mu}g/ml$ of CM(CM 0.1), stimulated by RANKL with 1 ${\mu}g/ml$ of CM(CM 1). Osteoclastogenesis was measured by counting Tartrate-resistant acid phosphatase-positive multinucleated cells [TRAP(+) MNC]. RT-PCR was performed to evaluate the inhibitory effect of CM on gene expression(TRAP, AKT1, JNK1, NFATc1, c-Fos, MITF). Results: 1. CM decreased the number of TRAP(+) osteoclast in RANKL-stimulated RAW 264.7 cell at the concentration of 0.1 ${\mu}g/ml$ and 1 ${\mu}g/ml$. 2. CM decreased the expression of TRAP in osteoclast at the concentration of 1 ${\mu}g/ml$. 3. CM decreased the expression of AKT1, JNK1 in osteoclast at the concentration of 1 ${\mu}g/ml$. 4. CM didn't affect the expression of NFATc1, c-Fos, MITF in osteoclast. Conclusions: Cordyceps militaris has inhibitory effects on osteoclast differentiation and its related gene expression. These results suggest that Cordyceps militaris has a potential as a treatment of osteoporosis.