• Journal of Physiology & Pathology in Korean Medicine
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• v.22 no.4
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• pp.802-809
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• 2008

Gamijangsing-tang (GMJST) has been used for treatment of bone formation in traditional korean medicine. The purpose of this study is to examine effects of GMJST on bone metabolism. The effects on the osteoblasts were determined by measuring (1) cell proliferation, (2) alkaline phosphatase (ALP) activity, (3) osteoprotegerin (OPG) secretion. (4) The morphologic changes of cells were observed by light microscopy and electron microscopy. Mineralization of calcium was determined by quantitative alizarin red-S assay and mineralization of phosphate was observed by von kossa staining. The morphologic changes of mineralization on the cells were observed by transmission electron microscopy (TEM). The effects on the osteoclast were investigated by tartrate-resistant acid phosphatase (TRAP) staining. Following results were obtained: Celluar activity of osteoblastic cells (MG-63) was significantly increased in 10-5 of dilution of GMJST. ALP and OPG activity of osteoblastic cells were increased in GMJST than normal MG-63 cell. Mineralization of osteoblastic cells were increased in GMJST than normal MG-63 cell. The activity of osteoclast cells (RAW 264.7) was significantly decreased in GMJST than normal MG-63 cell. From the results, GMJST stimulated the proliferation and mineralization of bone-forming osteoblast and inhibited by bone- lysis osteoclast.

• International Journal of Oral Biology
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• v.31 no.4
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• pp.119-125
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• 2006

The importance of phytoestrogens to human health is currently being actively investigated. Hesperidin, abundantly found in citrus fruits, is known to possess antioxidant, anticancer, and anti-inflammatory effects. Recently, it has been reported that hesperidin inhibits bone loss and decreases serum and hepatic lipids in ovariectomized mice. In our study, to determine the possible role of hesperidin in the regulation of bone metabolism, we observed the effects of hesperidin on the proliferation and activity of osteoblasts, as well as the effects of hesperidin on osteoclast generation and activity. We observed that, when treated with hesperidin, the number and viability of osteoblastic cells increased, alkaline phosphatase (ALP) activity of osteoblastic cells increased, and osteoprotegerin (OPG) secretion from MG63 cells decreased. Hesperidin treatment had no effect on the osteoclast generation and activity in the bone marrow cell culture, but decreased the number and resorptive activity of osteoclasts generated from RAW/264.7 cells. Taken together, these results indicate that hesperidin increases the proliferation and activity of osteoblasts, while inhibiting generation and activity of osteoclasts. Although the precise role of hesperidin remains to be elucidated, our study suggests that it is one of the important modulators of bone metabolism.

• BMB Reports
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• v.34 no.5
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• pp.421-427
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• 2001

Osteoclasts, cells primarily involved in bone resorption, originate from the hematopoietic precursor cells of the monocyte/macrophage lineage and differentiate into multinucleated mature forms. We developed an in vitro osteoclast culture system using embryonic chicken bone marrow cells. This culture system can be utilized in studies on the differentiation and function of osteoclasts. Phosphatidylinositol 3-kinase (PI3-kinase) and mitogen-activated protein kinases (MAPKs) have been implicated in diverse cellular functions including proliferation, migration, and survival. Using the developed avian osteoclast culture system, we examined the involvement of these kinases in osteoclast differentiation by employing specific inhibitors of the kinases. We Found that the inhibition of the PI 3-kinase, p38, or ERK interfered with osteoclast formation, suggesting that the signaling pathways that involve these molecules participate in the process of chicken osteoclast differentiation.

• BMB Reports
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• v.52 no.7
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• pp.469-474
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• 2019

Kruppel-like factor 2 (KLF2) has been implicated in the regulation of cell proliferation, differentiation, and survival in a variety of cells. Recently, it has been reported that KLF2 regulates the p65-mediated transactivation of $NF-{\kappa}B$. Although the $NF-{\kappa}B$ pathway plays an important role in the differentiation of osteoclasts and osteoblasts, the role of KLF2 in these bone cells has not yet been fully elucidated. In this study, we demonstrated that KLF2 regulates osteoclast and osteoblast differentiation. The overexpression of KLF2 in osteoclast precursor cells inhibited osteoclast differentiation by downregulating c-Fos, NFATc1, and TRAP expression, while KLF2 overexpression in osteoblasts enhanced osteoblast differentiation and function by upregulating Runx2, ALP, and BSP expression. Conversely, the downregulation of KLF2 with KLF2-specific siRNA increased osteoclast differentiation and inhibited osteoblast differentiation. Moreover, the overexpression of interferon regulatory protein 2-binding protein 2 (IRF2BP2), a regulator of KLF2, suppressed osteoclast differentiation and enhanced osteoblast differentiation and function. These effects were reversed by downregulating KLF2. Collectively, our data provide new insights and evidence to suggest that the IRF2BP2/KLF2 axis mediates osteoclast and osteoblast differentiation, thereby affecting bone homeostasis.

• YAKHAK HOEJI
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• v.53 no.2
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• pp.78-82
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• 2009

We explored the effects of dexamethasone on osteoclast precursors using BMMs. Dexamethasone inhibited the proliferation of BMMs. Furthermore, it stimulated the osteoclast formation via NFATc1 activation in the presence of RANKL. Since dexamethasone targeted the early stage of osteoclast formation, we investigated its effect on mRNA expression of GR and $IFN-{\beta}$. Whereas dexamethasone had no effects on GR expression in the presence of RANKL, it reduced the expression of $IFN-{\beta}$, suggesting that dexamethasone increased RANKL-induced osteoclast formation by modulating $IFN-{\beta}$.

• Preventive Nutrition and Food Science
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• v.19 no.4
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• pp.353-357
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• 2014

Phytic acid (myo-inositol hexakisphosphate) or phytate is considered an anti-nutrient due to the formation of precipitated complexes that strongly reduces the absorption of essential dietary minerals. In this study, brown rice with reduced phytate was made by inoculation with Lactobacillus sakei Wikim001 having high phytase activity. The effects of brown rice extract treated with L. sakei Wikim001 (BR-WK) on osteoblast differentiation and osteoclast formation were investigated. The proliferation of SaOS-2 cells was measured by the MTT assay. Treatment with BR-WK increased cell proliferation by 136% at a concentration of $100{\mu}g/mL$. The Alkaline phosphate activity in SaOS-2 cells was 129% higher when BR-WK was processed at a concentration of $100{\mu}g/mL$. The proliferation of bone marrow macrophages decreased by nearly 60% in response to treatment with BR-WK. In addition, BR-WK reduced the number of tartrate-resistant acid phosphatase-positive ($TRAP^+$) multinucleated cells from bone marrow macrophages. These results indicate that BR-WK stimulates bone formation through its positive action on osteoblast differentiation and function and furthermore, decreases osteoclast differentiation.

• The Journal of Korean Obstetrics and Gynecology
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• v.29 no.2
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• pp.66-82
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• 2016

Objectives : This study was conducted to evaluate the effect of Kanghwalsokdan-tang Gamibang water extract (KSG) on osteoporosis. Methods : RANKL-stimulated RAW 264.7 was used to evaluate inhibitory effect of KSG osteoclast differentiation and gene expression. We counted TRAP (+) multinucleated cells and measured TRAP activity and mRNA expressions of osteoclastogenesis-related genes (NFATc1, MITF, JNK1, cathepsin K, MMP-9) to figure out the effect of KSG on osteoclast. Osteoblastogenesis was also determined in rat calvarial cell. Alkaline phosphatase (ALP) activity, bone matrix protein and collagen synthesis were measured by using murine calvarial cell. Results : KSG inhibited the differentiation of osteoclast precursor cell and expression of genes related osteoclastogenesis like NAFTc1, MITF, c-fos, JNK1, Cathepsin K, MMP-9 and TRAP. KSG increased cell division and function of osteoblast separated from the skull of a rat and ALP synthesis, biosynthesis of bone matrix protein and collagen. Conclusions : Reviewing these results, KSG has efficacy on osteoclast inhibition and osteoblast activation. After further study, KSG will be able to apply for osteoporosis treatment and prevention.

• The Korea Journal of Herbology
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• v.35 no.3
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• pp.1-8
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• 2020

Objectives : In this study, we examined the estrogenic activities and anti-osteo clastogenesis effects of PCE17, a mixture of PE (an extract of Puerariae Flos), and CE (an extract of Citri Unshius Pericarpium). Methods : The estrogenic effect of PCE17, PE and CE were examined by ER-β/ERE reporter gene assay and proliferation assay in 293 T and MCF-7 cells. The expression of estrogen-responsive gene and protein were checked by Real Time-PCR (RT-PCR) and Western blotting in MCF-7 cells. Inhibitory effect of PCE17, PE and CE on RANKL-induced osteoclast differentiation were evaluated by TRAP staining and RT-PCR in primary osteoclast precursors from rat bone marrow cells. Results : PCE17 and PE bind to ERs (estrogen receptors) and show estrogenic activities in 293T cells. They also stimulated the proliferation of MCF-7 cells and increased the expression of ER response gene, pS2. Tectorigenin, an active ingredient of PE, shows similar estrogenic activities in MCF-7 cells. PCE17 and CE inhibited RANKL-induced osteoclastogenesis in rat primary osteoclast precursor cells and down-regulated the osteoclast-specific genes of Nfatc1, Ctsk, and Acp5. Conclusions : In conclusion, PCE17 may have therapeutic potential in cases of menopause and osteoporosis.

• Experimental and Molecular Medicine
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• v.50 no.11
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• pp.2.1-2.16
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• 2018

Supplementation of mesenchymal stem cells (MSCs) at sites of bone resorption is required for bone homeostasis because of the non-proliferation and short lifespan properties of the osteoblasts. Calcium ions ($Ca^{2+}$) are released from the bone surfaces during osteoclast-mediated bone resorption. However, how elevated extracellular $Ca^{2+}$ concentrations would alter MSCs behavior in the proximal sites of bone resorption is largely unknown. In this study, we investigated the effect of extracellular $Ca^{2+}$ on MSCs phenotype depending on $Ca^{2+}$ concentrations. We found that the elevated extracellular $Ca^{2+}$ promoted cell proliferation and matrix mineralization of MSCs. In addition, MSCs induced the expression and secretion of osteopontin (OPN), which enhanced MSCs migration under the elevated extracellular $Ca^{2+}$ conditions. We developed in vitro osteoclast-mediated bone resorption conditions using mouse calvaria bone slices and demonstrated $Ca^{2+}$ is released from bone resorption surfaces. We also showed that the MSCs phenotype, including cell proliferation and migration, changed when the cells were treated with a bone resorption-conditioned medium. These findings suggest that the dynamic changes in $Ca^{2+}$ concentrations in the microenvironments of bone remodeling surfaces modulate MSCs phenotype and thereby contribute to bone regeneration.

• Journal of Oral Medicine and Pain
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• v.32 no.2
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• pp.129-135
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• 2007

Ecdysteroids are known as insect molting hormone. At the same time, ecdysteroids and plant ecdysteroids (phytoecdysteorids) reveal beneficial effects on mammal. The present study was undertaken to determine the possible cellular mechanism of action of phytoecdysteroids in bone metabolism. The effects on the osteoblasts were determined by measuring cell proliferation, alkaline phosphatase (ALP) activity, and gelatinase activity. The effects on the osteoclasts were investigated by measuring tartrate-resistant acid phosphatase (TRAP)(+) multinucleated cells (MNCs) formation after culturing osteoclast precursors. Phytoecdysteroid treatment showed a increase in ALP activity of osteoblasts. Phytoecdysteroid increased the activity of gelatinase. In addition, phytoecdysteroid decreased the osteoclast generation induced by macrophage-colony stimulating factor (M-CSF) and receptor activator of NF-kB ligand (RANKL) in (M-CSF)-dependent bone marrow macrophage (MDBM) cell cultures. Taken these results, phytoecdysteroid may be a regulatory protein within the bone marrow microenvironment.