• The Korea Journal of Herbology
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• v.38 no.5
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• pp.9-19
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• 2023

Objectives : Osteoporosis is a systemic skeletal disorder characterized by reduced bone mineral density and increased risk of fractures. Bisphosphonates and selective estrogen receptors, which are bone resorption inhibitors that are currently widely used as osteoporosis treatments, show serious side effects when administered for a long time. Research on bone resorption inhibitors that complement the problems of existing treatments is needed. The purpose of this study was to investigate the effect of inhibiting osteoclast differentiation and activity on the tuberous root of Ampelopsis japonica (Thunb.) Makino (AM). Methods : After extracting AM using distilled water and ethanol, the inhibitory effects of the two solvents on osteoclast differentiation were compared using the RANKL-induced in vitro experimental model and the TRAP assay kit. The impact of AM on bone resorption was investigated through the pit formation assay, and its effect on F-actin formation was assessed through fluorescent staining. Additionally, protein and mRNA expression levels of osteoclast differentiation markers (NFATc1, c-Fos, TRAP and ATP6v0d2) and resorption markers (MMP-9, CTK, and CA2) were analyzed via western blot and RT-PCR. Results : AM treatment significantly decreased the number of TRAP-positive cells and pit formation area. Furthermore, AM suppressed both the protein and mRNA expression of NFATc1 and c-Fos, key transcription factors involved in osteoclast differentiation and it downregulated the expression of osteoclast-associated genes such as TRAP, CTK, MMP-9, CA2, and ATP6v0d2. Conclusions : These results suggest that AM can inhibit bone resorption and osteoclast differentiation, indicating its potential for use in the treatment and prevention of osteoporosis.

• Journal of the korean academy of Pediatric Dentistry
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• v.27 no.2
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• pp.309-317
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• 2000

Bisphosphonates inhibit bone resorption in vivo and in vitro. Currently proposed mechanism of action of bisphosphonates involves both direct effect on osteoclasts and indirect effect through the mediation of osteoblasts. Recent understanding of molecular mechanism of osteoclastogenesis indicates that osteoclast differentiation is quite tightly regulated by signaling molecules from differentiating osteoblasts. Therefore this investigation was designed to elucidate the effect of bisphosphonate on osteoblast differentation. For this purpose, in vitro effects of etidronate and alendronate on the expression of Cbfa1 a master control gene of osteoblast differentiation, several bone marker genes, and formation of calcified nodules were evaluated. To evaluate the effect of bisphosphonate on calcified nodule formation, osteoblasts isolated from rat calvaria were cultured in a-MEM containing $10^{-4},\;10^{-5},\;10^{-6}M$ of etidronate or $10^{-6},\;10^{-7},\;10^{-8}M$ of alendronate for 15 days, and then stained by alizarin red to determine mineralization. To evaluate the effect of bisphosphonate on osteoblast differentiation, osteoblast cells were cultured in a-MEM containing $10^{-4},\;10^{-5},\;10^{-6}M$ of etidronate or $10^{-6}$ M of alendronate for 8 days. And then total RNA was extracted and northern blot analysis was done to examine the expression of Cbfa1, type I collagen, alkaline phosphatase, osteopontin and osteocalcin. The results were as follows: 1. Etidronate suppressed the calcification of bone nodule in dose dependent manner, while alendronate didn't. 2. The expression of Cbfa1 was decreased dose dependently by etidronate, but increased by alendronate. 3. Etidronate suppressed the expression of type I collagen, osteopontin and osteocalcin in dose dependent manner however alendronate promote the expression of osteoblast marker gene. 4. The expression of alkaline phosphatase was not affected either etidronate nor alendronate. These results suggest that etidronate suppressed the expression of Cbfa1 in dose dependent manner, and consequently the expression of osteoblast marker genes, such as type I collagen, osteopontin and osteocalcin were also suppressed in similar manner. And finally this decreased expression of osteoblastic marker gene prevent calcined bone nodule formation.

• Journal of the korean academy of Pediatric Dentistry
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• v.33 no.2
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• pp.290-303
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• 2006

Tooth eruption is a complex and tightly regulated process that involves cells of the tooth organ and the surrounding alveolus. Osteoclast precursors must be recruited into the dental follicle prior to the onset of eruption. This function of dental follicle may be regarded as the ability of bone remodeling characterized by the interaction of osteoclasts and osteoblasts. This is because tooth eruption is a localized event in which many of the genes required for eruption are expressed in the dental follicle. RANKL is a membrane-bound protein that is a member of the TNF ligand family. which is present on bone marrow stromal cells and osteoblasts, and induces osteoclast formation and activation from precursor cell. The biologic effect of RANKL is inhibited by OPG and, in bone, the relative ratio of RANKL and OPG modulates osteoclastogenesis. To evaluate the roles of RANKL and OPG in tooth eruption and the relations with the expression pattern of Runx2, in situ hybridization was performed with mandibles of mice at postnatal stage 1, 3, 5, 7, 9 and 11. mRNA of RANKL, OPG, and Runx2 are expressed in dental follicle and surrounding tissue from P1 to 11. To determine the sites of osteoclastic activity during tooth eruption, mandibles were dissected. Peak osteoclastic activity in alveolar bone along the occlusal and basal regions was observed from P5 to 9, with osteoclasts in these regions being large and strongly TRAP-positive The specific spatio-temporal expression patterns of RANKL, OPG, and Runx2 in our study suggest that tooth eruption could be progressed through the interactions of molecular signaling among dental follicle, dental organ and alveolar bone, furthermore it means that dental follicle is quite important in tooth eruption In addition, it indicates that these genes (RANKL, OPG, and Runx2) play critical roles in tooth eruption.

• Journal of Life Science
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• v.29 no.10
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• pp.1104-1110
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• 2019

Recently, there has been an increase in the elderly population of the world. Consequently, bone metabolic diseases such as osteoporosis are emerging as a social problem. Osteoclasts play a role in bone resorption, and osteoporosis is induced when bone resorption occurs excessively. Because currently used bone resorption inhibitors may cause side effects when used for a long period of time, it is necessary to develop a new material that effectively inhibits osteoclast differentiation. This study aimed to confirm the inhibitory effect of ethanol extract of Locusta migratoria on RANKL-induced osteoclast differentiation and its mechanism. The toxicity and proliferation effects of LME on RAW264.7 osteoclasts were measured by an MTS assay. There was no cytotoxicity or proliferation when the osteoclasts were treated with up to $2,000{\mu}g/ml$ of LME. In order to confirm the effect of LME on the differentiation of osteoclasts, osteoclasts were treated with RANKL alone or with LME for 3 days. As a result of a TRAP (tartrate-resistant acid phosphatase) assay, the increasing osteoclast differentiation by RANKL decreased in a concentration-dependent manner with the treatment of LME. In addition, LME suppressed the expression of differentiation-related marker genes (TRAP, RANK, NFATc1, and CK) and proteins (NFATc1 and c-Src) that had been increased by RANKL. Also, LME influenced the $NF-{\kappa}B$, ERK and JNK signaling pathways, resulting in the inhibition of osteoclast differentiation. These results suggest that LME may be used as a novel functional material for the prevention and treatment of osteoporosis by playing a role in inhibiting bone absorption.