• The korean journal of orthodontics
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• v.25 no.6 s.53
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• pp.705-714
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• 1995

Due to the great deal of effort that has gone into the study of osteoclastic differentiation and activation over the last few decades, the mechanisms of these two events have been discovered gradually. Nitric oxide($NO^-$), which is produced from arginine by a nitric oxide synthase, opened up a new area of biological research. Recently, it has been reported that $NO^-$ is produced by osteoblasts stimulated by lipopolysaccharide and several other cytokines. In this study, the effect of sodium nitroprusside(SNP), a donor of nitric oxide($NO^-$), on osteoclast-like cell formation and on mature osteoclast function was examined. To determine the mechanism of the inhibitory effects of SNP decreased not only the basal $^{45}Ca$ release but also thee bone resorption induced by PTH and 1,25-dihydroxyvitamin $D_3\;(1,25[OH]_{2}D_3)$. The inhibitory effect of SNP on bone resorption induced by PTH appeared 2 dyas after treatment, whereas SNP effect on inhibiting bone resorption induced by $1,25[OH]_{2}D_3$ appeared at the thhird days. When chicken and rat osteeoclasts were cultured on dentin slices, treatment of $300{\mu}M$ SNP resulted in a significant decrease in dentin resorption by osteoclasts in terms of total resolution area and average individual area. We also examind the effect of SNP on formation of osteoclast-like cells that is TRAP-positive multinucleated cells from chicken and rat bone marrow cells in the presence or absence of $10^{-8}\;M\;1,25[OH]_{2}D_3$. The addition of $300{\mu}M$ SNP inhibiteed the formation of TRAP-positive multinucleated cells. The present data suggest that SNP, possibly as a $NO^-$ donor, inhibits the osteoclastic differentiation and osteoclastic activity.

• Imaging Science in Dentistry
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• v.35 no.3
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• pp.133-139
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• 2005

Purpose To observe the histopathological changes in the periodontal tissues of mandibular molars in streptozotocin-induced diabetic rats after irradiation. Materials and Methods : The male Sprague-Dawley rats weighing approximately 250 gm were divided into four groups: control, diabetes, irradiation, and diabetes- irradiation groups. Diabetes mellitus was induced in the rats by injecting streptozotocin. Rats in the control and irradiation groups were injected with citrate buffer only After 5days, the head and neck region of the rats in irradiation and diabetes-irradiation groups were irradiated with a single absorbed dose of 10Gy. All the rats were sacrificed at 3, 7, 14, 21, and 28 days after irradiation. The specimen including the mandibular molars were sectioned and observed using a histopathological method. Results In the diabetes group, osteoclastic activity was observed in the alveolar bone and the root throughout the period of experiment. Also, osteoblastic and fibroblastic activities were markedly decreased. In the irradiation group, the osteoclasts were observed in the alveolar bone and the dilated capillaries were increased in the early experimental phases. However, vigorous osteoblastic activity was noted in the late experimental phases. In the diabetes-irradiation group, osteoblastic activity in the alveolar bone and the root was observed in the early experimental phases. However, there were no resorption and osteoblastic activity in the alveolar bone and the root in the late experimental phases, and obvious atrophic change of fibrous tissues was noted. Conclusion : This experiment suggests that osteoblastic activity was caused by irradiation in the late experimental phases, but atrophic change of the periodontal ligament tissues was induced after irradiation in diabetic state.

• Journal of Physiology & Pathology in Korean Medicine
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• v.24 no.5
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• pp.807-813
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• 2010

Impairment of balance between bone-resorbing osteoclasts and bone-forming osteoblasts result in bone disease. Especially, increased osteoclast formation and activity are responsible for bone diseases such as osteoporosis, rheumatoid arthritis, periodontal disease. Natural metabolites of plants have recently received much attention as an alternative tools for the development of novel therapeutic strategy. The aim of this study was to search the natural products to inhibit osteoclast differentiation and was to evaluate of its mechanism. Water extract of Gastrodia elata Blune significantly inhibited receptor activator of nuclear factor-κB ligand (RANKL)-induced osteoclast differentiation in bone marrow macrophages (BMMs) in a dose dependent manner. However, water extract of Gastrodia elata Blune did not affect cytotoxicity when compared with control. The mRNA expression of c-Fos, NFATc1, and TRAP induced by RANKL was inhibited by water extract of Gastrodia elata Blune treatment. Also, water extract of Gastrodia elata Blune inhibited the protein expression of c-Fos and NFATc1 expression in BMMs treated with RANKL. Water extract of Gastrodia elata Blune suppressed the phosphorylation of p38 induced by RANKL. In general, RANKL considerably inhibited the expression level of Id2 and MafB known as negative regulators of osteoclastogenesis, but RANKL did not inhibit Id2 and MafB expression in BMMs when it was co-treated with Gastrodia elata Blune. Taken together, these results suggest that Gastrodia elata Blune may be a useful drug in the treatment of bone-related disease.

• Journal of Physiology & Pathology in Korean Medicine
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• v.22 no.4
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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.

• Korean Journal of Oriental Medicine
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• v.13 no.2 s.20
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• pp.157-164
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• 2007

An imbalance in bone remodeling that is caused by increased bone resorption over bone formation leads to most adult skeletal diseases including osteoporosis. Since the development of anti-resorptive agents from natural substances has recently gained more interest in the treatment of osteoporosis, we evaluated the effects of 222 natural compounds on receptor activator of $NF-{\kappa}B$ ligand (RANKL)-induced of tartrate-resistance acid phosphatase (TRAP) activity in RAW264.7 murine macrophage cell, and found that berberine chloride is one of compounds inhibiting RANKL-induced TRAP activity. Berberine chloride significantly inhibited the RANKL-induced TRAP activity and the formation of multinucleated osteoclasts in a dose-dependent manner. In addition, berberine chloride prevented the RANKL-induced mRNA expression of TRAP, matrix metalloproteinase 9 and c-Src, which have been known to be highly expressed in the process of osteoclastogenesis. Interestingly, berberine chloride prevented the RANKL-induced activation of extracellular signal-regulated kinase (ERK) which is one of mitogen-activated protein (MAP) kinases. In conclusion, berberine chloride could inhibit the osteoclastogenesis via preventing the activation of ERK/MAP kinase signaling pathway.

• Biomedical Science Letters
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• v.23 no.4
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• pp.327-332
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• 2017

A2B adenosine receptor (A2BAR) is known to be a regulator of bone homeostasis, but the regulatory mechanism of A2BAR on the osteoclast proliferation are poorly explored. Recently, we have shown that stimulation with BAY 60-6583, a specific agonist of A2BAR, significantly reduced macrophage-colony stimulating factor (M-CSF)-induced osteoclast proliferation by inducing cell cycle arrest at G1 phase and increasing the apoptosis of osteoclasts. The objective of this study was to investigate the regulatory mechanisms of cell cycle and apoptosis by A2BAR stimulation. The expression of A2BAR and M-CSF receptor, c-Fms, was not changed by A2BAR stimulation whereas M-CSF effectively induced c-Fms expression during osteoclast proliferation. Interestingly, A2BAR stimulation remarkably increased the expression of $p27^{Kip-1}$, a cell cycle inhibitor, but the expression of Cyclin D1 and cdk4 was not affected. In addition, while BAY 60-6583 treatment reduced the expression of Bcl2, an anti-apoptotic oncogene, it failed to regulate the expression of Bax, a pro-apoptotic marker. Taken together, these results imply that the increase of $p27^{Kip-1}$ inducing cell cycle arrest at G1 phase and the decrease of Bcl2 inducing anti-apoptotic response by A2BAR stimulation contribute to the down-regulation of osteoclast proliferation.

• BMB Reports
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• v.51 no.7
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• pp.356-361
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• 2018

Actin-binding LIM protein 1 (ABLIM1), a member of the LIM-domain protein family, mediates interactions between actin filaments and cytoplasmic targets. However, the role of ABLIM1 in osteoclast and bone metabolism has not been reported. In the present study, we investigated the role of ABLIM1 in the receptor activator of $NF-{\kappa}B$ ligand (RANKL)-mediated osteoclastogenesis. ABLIM1 expression was induced by RANKL treatment and knockdown of ABLIM1 by retrovirus infection containing Ablim1-specific short hairpin RNA (shAblim1) decreased mature osteoclast formation and bone resorption activity in a RANKL-dose dependent manner. Coincident with the downregulated expression of osteoclast differentiation marker genes, the expression levels of c-Fos and the nuclear factor of activated T-cells cytoplasmic 1 (NFATc1), critical transcription factors of osteoclastogenesis, were also decreased in shAblim1-infected osteoclasts during RANKL-mediated osteoclast differentiation. In addition, the motility of preosteoclast was reduced by ABLIM1 knockdown via modulation of the phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K)/Akt/Rac1 signaling pathway, suggesting another regulatory mechanism of ABLIM1 in osteoclast formation. These data demonstrated that ABLIM1 is a positive regulator of RANKL-mediated osteoclast formation via the modulation of the differentiation and PI3K/Akt/Rac1-dependent motility.

• Journal of Microbiology and Biotechnology
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• v.16 no.1
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• pp.37-45
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• 2006

Treatment with exopolymers of Aureobasidium pullulans SM-2001 containing $\beta-1,3/1,6-glucan$ inhibited osteoclastogenesis of bone marrow stem cells in a co-culture system with calvariae osteoblastic cells. In addition, the treatment increased mineral deposition in osteoblastic cells. These two observations prompted us to evaluate whether the exopolymers could be used as an anti-osteoporotic agent, and efficacy of the exopolymers to prevent bone loss was compared with alendronate, a bisphosphonate, in ovariectomized mice prone to osteoporosis. Administration of the exopolymers to the ovariectomized mice resulted in improved effects on femur weight and histomorphometric changes of femur such as trabecular bone volume (TBV), trabecular bone thickness (TBT), and cortical bone thickness (CBT). In conclusion, the exopolymers treatment inhibited bone loss from osteoporosis induced by ovariectomy, and the effect was comparable to alendronate administration.

• Journal of Pharmaceutical Investigation
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• v.27 no.4
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• pp.323-329
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• 1997

Ipriflavone is non-hormonal antiosteoporotic drug which inhibits bone resorption by reducing recruitment and/or differentiation of osteoclasts, and stimulates proliferation and differentiation of osteoblast, and also enhances calcitonin secretion in the presence of estrogen. Although some kinds of immediately-released preparation of ipriflavone are available in commercial market, in present study, we tried to formulate sustained-release tablet using coating method with hydrophobic and hydrophilic coating materials. In vitro dissolution test was applied to evaluate sustained-release patterns of several test preparations (Test tablet A, B and C) designed using different preparation method or different compositions. From the results of dissolution test, test tablet A which showed suitable dissolution profile was selected as the candidate of new product. Pharmacokinetic evaluation of test drug, ipriflavone sustained-release tablets, was conducted in 6 beagle dogs weighing $11.5{\pm}0.5\;Kg$ compared with $Theobon^{\circledR}$ tablet, immediately-released tablet (Kukjae Pharm. Co.) as reference drug. Two products were randomly administered to 6 beagle dogs, and after 1 week, cross-over study was conducted. From the present study, AUC and $T_{max}$ of test product were significantly different from those of reference product (p<0.05), respectively$(AUC\;:\;3646.28{\pm}472.56\;vs\;3646.28{\pm}472.56\;ng{\cdot}hr/ml,\;T_{max}\;:\;4.33{\pm}1.03\;vs\;1.42{\pm}0.38\;hr)$. But $C_{max}$ was not significantly different between two products (p>0.05) $(\;512.52{\pm}48.18\;vs\;443.97{\pm}140.53\;ng/ml)$. From the results of pharmacokinetic evaluations, it was noted that absorption amount of test product was increased, but absorption rate was delayed and $C_{max}$ of two products were not changed. And it was concluded that redesign of the sustained-release preparation which has a lower content of iprifavone rather than test tablet A must be considered.

• The Korean Journal of Physiology and Pharmacology
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• v.17 no.5
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• pp.427-433
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• 2013

Receptor activator of NF-${\kappa}B$ ligand (RANKL)-induced osteoclastogenesis is accompanied by intracellular $Ca^{2+}$ mobilization in a form of oscillations, which plays essential roles by activating sequentially $Ca^{2+}$/calmodulin-dependent protein kinase, calcineurin and NFATc1, necessary in the osteoclast differentiation. However, it is not known whether $Ca^{2+}$ mobilization which is evoked in RANKL-independent way induces to differentiate into osteoclasts. In present study, we investigated $Ca^{2+}$ mobilization induced by aluminum fluoride ($AlF_4^-$), a G-protein activator, with or without RANKL and the effects of $AlF_4^-$ on the osteoclastogenesis in primary cultured mouse bone marrow-derived macrophages (BMMs). We show here that $AlF_4^-$ induces intracellular $Ca^{2+}$ concentration ($[Ca^{2+}]_i$) oscillations, which is dependent on extracellular $Ca^{2+}$ influx. Notably, co-stimulation of $AlF_4^-$ with RANKL resulted in enhanced NFATc1 expression and formation of tartrate-resistant acid phosphatase (TRAP) positive multinucleated cells. Additionally, we confirmed that mitogen-activated protein kinase (MAPK) is also activated by $AlF_4^-$. Taken together, these results demonstrate that G-protein would be a novel modulator responsible for $[Ca^{2+}]_i$ oscillations and MAPK activation which lead to enhancement of RANKL-mediated osteoclastogenesis.