• International Journal of Oral Biology
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• 제38권1호
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• pp.37-42
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• 2013

Receptor activator of NF-${\kappa}B$ ligand (RANKL) is an essential cytokine for osteoclast differentiation, activation and survival. T lymphocytes such as $T_{17}$ cells, a subset of T helper cells that produce IL-17, play an important role in rheumatoid arthritic bone resorption by producing inflammatory cytokines and RANKL. It has not yet been clearly elucidated how T cell activation induces RANKL expression. T cell receptor activation induces the activation of nuclear factor of activated T cell (NFAT) and expression of its target genes. In this study, we examined the role of NFAT in T cell activation-induced RANKL expression. EL-4, a murine T lymphocytic cell line, was used. When T cell activation was induced by phorbol 12-myristate 13-acetate (PMA) and ionomycin, RANKL expression increased in a time-dependent manner. In the presence of cyclosporin, an inhibitor of NFAT activation, this PMA/ionomycin-induced RANKL expression was blocked. Overexpression of either NFATc1 or NFATc3 induced RANKL expression. Chromatin immunoprecipitation results demonstrated that PMA/ionomycin treatment induced the binding of NFATc1 and NFATc3 to the mouse RANKL gene promoter. These results suggest that NFATc1 and NFATc3 mediates T cell receptor activation-induced RANKL expression in T lymphocytes.

• Molecules and Cells
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• 제37권10호
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• pp.747-752
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• 2014

Protein kinase C (PKC) family members phosphorylate a wide variety of protein targets and are known to be involved in diverse cellular signaling pathways. However, the role of PKC in receptor activator of NF-${\kappa}B$ ligand (RANKL) signaling has remained elusive. We now demonstrate that $PKC{\beta}$ acts as a positive regulator which inactivates glycogen synthase kinase-$3{\beta}$ (GSK-$3{\beta}$) and promotes NFATc1 induction during RANKL-induced osteoclastogenesis. Among PKCs, $PKC{\beta}$ expression is increased by RANKL. Pharmacological inhibition of $PKC{\beta}$ decreased the formation of osteoclasts which was caused by the inhibition of NFATc1 induction. Importantly, the phosphorylation of GSK-$3{\beta}$ was decreased by $PKC{\beta}$ inhibition. Likewise, down-regulation of $PKC{\beta}$ by RNA interference suppressed osteoclast differentiation, NFATc1 induction, and GSK-$3{\beta}$ phosphorylation. The administration of PKC inhibitor to the RANKL-injected mouse calvaria efficiently protected RANKL-induced bone destruction. Thus, the $PKC{\beta}$ pathway, leading to GSK-$3{\beta}$ inactivation and NFATc1 induction, has a key role in the differentiation of osteoclasts. Our results also provide a further rationale for $PKC{\beta}$'s therapeutic targeting to treat inflammation-related bone diseases.

• Journal of Acupuncture Research
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• 제32권3호
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• pp.27-40
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• 2015

Objectives : This study was performed to evaluate the effects of water extract of Cervi Parvum Cornu(CPC), Aconiti Lateralis Radix Preparata(ALR), and Yongbu-tang(YBT) on suppression of the receptor activator of nuclear factor kappa-B ligand(RANKL)-induced osteoclast differentiation and bone resorption. Methods : The effects of CPC, ALR, YBT extracts on osteoclast differentiation were determined by culture of bone marrow macrophage(BMM). The mRNA expression levels of the nuclear factor of activated T-cells cytoplasmic 1(NFATc1), c-Fos and tartrate-resistant acid phosphatase(TRAP) in BMMs were analyzed by reverse transcriptase polymerase chain reaction(RT-PCR). Similarly, the protein expression levels of NFATc1, c-Fos, mitogen-activated protein kinase(MAPK)s and ${\beta}$-actin in cell lysates were measured by western blotting. In addition, effects of CPC, ALR and YBT extracts were determined by means of Lipopolysaccharide(LPS)-induced bone-loss with mice. Results : CPC, ALR and YBT extracts showed remarkable inhibition on RANKL-induced osteoclast differentiation without cytotoxicity. CPC and ALR extracts significantly reduced the protein expression level of NFATc1. YBT extract significantly reduced the mRNA expression levels of c-Fos, NFATc1 and the protein expression levels of c-Fos, NFATc1, AKT, p38, c-Jun N-terminal kinase(JNK). Further, YBT extract suppressed degradation of$ I-{\kappa}B$. And ALR extract significantly restored the bone erosion by LPS treatment in mice. Conclusions : YBT extract showed more remarkable inhibition on osteoclast differentiation than CPC and ALR extracts in vitro. ALR extract showed remarkable inhibition on bone resorption in vivo. Thus, YBT extract can be a useful treatment for bone-loss diseases such as osteoporosis.

• Journal of Acupuncture Research
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• 제32권3호
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• pp.69-81
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• 2015

Purpose : The first purpose of this study is to find out whether the water extract of Rehmanniae Radix Preparat(RRP), Cuscutae Semen(CS) and their combination(Ssangbohwan, SBH) have the effect of suppressing Receptor activator of nuclear factor kappa-B ligand(RANKL)-induced osteoclast differentiation. The second purpose of this study is to find out whether the water extract of RRP, CS and SBH have the effect of inhibiting osteoporosis in an osteoporosis model induced by lipopolysaccharide(LPS). Methods : After promoting differentiation of osteoclasts by treating the RANKL, we observed the effect by the administration of RRP, CS and SBH. In addition, by means of Reverse transcription polymerase chain reaction(RT-PCR), we assayed mRNA expression levels of NFATc1, c-Fos, TRAP and GAPDHS(Glyceraldehyde-3-phosphate dehydrogenase, spermatogeni) from bone marrow macrophages(BMMs). Similarly, the protein expression levels of NFATc1 (Nuclear factor of activated T-cells, cytoplasmic1), C-Fos, MAPKs(Mitogen-activated protein kinases) and ${\beta}$-actin in cell lysates were analyzed by means of Western Blotting. Finally, we determined the anti-osteoporotic effects of RRP, CS and SBH, through the use of Lipopolysaccharide-induced bone-loss mouse. Results : RRP, CS and SBH showed remarkable inhibitive effect on RANKL-treated osteoclast differentiation without cytotoxicity. SBH inhibited the phosphorylation of p38, Jun N-terminal kinases(JNK), and I-${\kappa}B$ and down-regulated the induction of c-Fos and NFATc1 by RANKL. RRP, CS suppressed degradation of I-${\kappa}B$, but it did not affect c-Fos and NFATc1 by RANKL. Lastly, in vivo data showed that RRP and SBH prevented bone erosion by LPS treatment. Conclusions : These results demonstrate SBH can be effective remedy for bone-loss diseases such as osteoporosis.

• 대한한의학회지
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• 제38권3호
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• pp.59-72
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• 2017

Objectives: This study was performed to evaluate effects of Sochungryong-tang Extract(SRE) on osteoclast differentiation and bone resorptionin order to find out the possibility for clinical use in preventing and treating osteoporosis. Methods: To evaluate the effect of SRE on osteoclast differentiation, we induced RAW 264. 7 cells to be differentiated to osteoclasts by RANKL (receptor activator of nuclear $factor-{\kappa}B$ ligand). We measured effect on TRAP (Tartrate-resistant acid phosphatase), NFATc, cathepsin K, MMP-9, inflammation related factors, histogenesis factors and bone resorption. Results: SRE decreased osteoclast differentiation, and also decreased expression of bone resorbing factors such as MMP-9, cathepsin K, TRAP, NFATc1, MITF, c-Fos, osteoclast stimulatory transmembrane protein, calcitonin receptor in RANKL-induced osteoclast. SRE also decreased Cyclooxygenase-2, indusible nitric oxide synthase, $TNF-{\alpha}$, which are thought to be related with the inflammatory bone destruction. Conclusion: SRE inhibits osteoclast differentiation and bone resorption. The results indicate that the BHT extract can potentially be applied for preventing and treating osteoporosis.

• International Journal of Oral Biology
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• 제38권2호
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• pp.67-72
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• 2013

This study examined the anti-osteoclastogenic effects of baicalin on receptor activator of NF-${\kappa}$B ligand (RANKL)-induced RAW264.7 cells. Baicalin is a flavonoid that is produced by Scutellaria baicalensis and is known to have multiple biological properties, including antibacterial, anti-inflammatory and analgesic effects. The effects of baicalin on osteoclasts were examined by measuring 1) cell viability; 2) the formation of tartrate-resistant acid phosphatase (TRAP) (+) multinucleated cells; 3) RANK/RANKL signaling pathways and 4) mRNA levels of osteoclast-associated genes. Baicalin inhibited the formation of RANKL-stimulated TRAP (+) multinucleated cells and also suppressed the RANKL-stimulated activation of p-38, ERK, cSrc and AKT signaling. Baicalin also inhibited the RANKL-stimulated degradation of $I{\kappa}B$ in RAW264.7 cells. In addition, the RANKL-stimulated induction of NFATc1 transcription factors was found to be abrogated by this flavonoid. Baicalin was further found to decrease the mRNA expression of osteoclast-associated genes, including carbonic anhydrase II, TRAP and cathepsin K in the RAW264.7 cells. Our data thus demonstrate that baicalin inhibits osteoclastogenesis by inhibiting the RANKL-induced activation of signaling molecules and transcription factors in osteoclast precursors.

• 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.

• BMB Reports
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• 제45권3호
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• pp.171-176
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• 2012

Receptor activator of NF-${\kappa}B$ ligand (RANKL) triggers the differentiation of bone marrow-derived monocyte/macrophage precursor cells (BMMs) of hematopoietic origin into osteoclasts through the activation of mitogen-activated protein (MAP) kinases and transcription factors. Recently, reactive oxygen species (ROS) and antioxidant enzymes were shown to be closely associated with RANKL-mediated osteoclast differentiation. Although glutaredoxin2 (Glrx2) plays a role in cellular redox homeostasis, its role in RANKL-mediated osteoclastogenesis is unclear. We found that Glrx2 isoform b (Glrx2b) expression is induced during RANKLmediated osteoclastogenesis. Over-expression of Glrx2b strongly enhanced RANKL- mediated osteoclastogenesis. In addition, Glrx2b-transduced BMMs enhanced the expression of key transcription factors c-Fos and NFATc1, but pre-treatment with SB203580, a p38-specific inhibitor, completely blocked this enhancement. Conversely, down-regulation of Glrx2b decreased RANKL- mediated osteoclastogenesis and the expression of c-Fos and NFATc1 proteins. Also, Glrx2b down-regulation attenuated the RANKL-induced activation of p38. Taken together, these results suggest that Glrx2b enhances RANKL-induced osteoclastogenesis via p38 activation.

• 대한한방부인과학회지
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• 제27권3호
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• pp.12-27
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• 2014

Objectives: This study was performed to evaluate the effect of Guibi-tang water extract (GB) on osteoporosis. Methods: We examined the effect of GB on osteoclast differentiation using murine pre-osteoclastic RAW 264.7 cells treated with receptor activator of nuclear factor kappa-B ligand (RANKL). The effect of GB on osteoclast was measured by counting TRAP (+) multinucleated cells and measuring TRAP activity. The mRNA expressions of osteoclastogenesis-related genes (Cathepsin K, MMP-9, TRAP, NFATc1, MITF, TNF-${\alpha}$, IL-6, COX-2) were measured by real-time PCR. We examined the effect of GB on osteoblast proliferation, ALP activity, bone matrix protein synthesis and collagen synthesis using murine calvarial cell. Results: GB decreased the number of TRAP (+) multinucleated cells and inhibited TRAP activity in RANKL-stimulated RAW 264.7 cell. GB decreased the expression of genes related osteoclastogenesis such as Cathepsin K, MMP-9, TRAP, NFATc1, MITF, COX-2 in RANKL-stimulated RAW 264.7 cell. But GB did not decrease the expression of iNOS and increased the expression of TNF-${\alpha}$, IL-6 in RANKL-stimulated RAW 264.7 cell. These genes (iNOS, TNF-${\alpha}$, IL-6) are thought to be related with the inflammatory bone destruction. GB increased cell proliferation of rat calvarial cell and also increased ALP activity in rat calvarial cell. GB did not increase bone matrix protein synthesis but increased collagen synthesis in rat calvarial cell. Conclusions: This study suggests that GB may be effective in treating osteoporosis by inhibiting osteoclast differentiation and its related gene expression and by increasing osteoblast proliferation.

• 동의생리병리학회지
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• 제26권3호
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• pp.320-324
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• 2012

Osteoporosis is an important public health issue in postmenopausal women. It is a major public health concern and is widely believed that osteoporosis results from imbalance between bone resorption and bone formation. Recently natural products from plants have been extensively studied as therapeutic drugs to treat and prevent various diseases. Hoelen (scientific name, Poria cocos) is a mushroom that is used in traditional Chinese medicine. Hoelen exhibits anti-inflammatory activity and has a protective effect on tumor progression. However, the effect of hoelen in osteoclast differentiation remains unknown. Thus, we examined the effect of hoelen in receptor activator of nuclear factor-${\kappa}B$ ligand (RANKL)-induced osteoclast differentiation. Hoelen significantly inhibited RANKL-induced osteoclast differentiation in bone marrow-derived macrophages (BMMs) in dose dependent manner without toxicity. Also, we showed that hoelen significantly inhibited the mRNA expression of tartrate-resistant acid phophatase (TRAP) and nuclear factor of activated T cells 1 (NFATc1) in BMMs treated with RANKL. In Particular, hoelen greatly inhibited the protein expression of NFATc1. Ectopic expression of NFATc1 partially reverses hoelen-mediated inhibition of osteoclast differentiation. Taken together, our results demonstrated that hoelen may be useful treatment option of bone-related disease such as osteoporosis, reumatoid arthritis, and periodontitis.