• Journal of Marine Bioscience and Biotechnology
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• v.5 no.4
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• pp.1-7
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• 2011

Bone health is maintained by balance between bone resorption and bone formation, and bone homeostasis requires balanced interactions between osteoblasts and osteoclasts. Most of drugs and functional foods for bone health have been developed as bone resorption inhibitors, which maintain bone mass by inhibiting the function of osteoclasts. The recent studies have shown beneficial effects of marine natural products on bone health. Therefore, this review is aimed to study effects of marine-derived natural substances on osteoarthritis inhibition via attenuation of MMPs and osteoblastic differentiation via activation of alkaline phosphatase (ALP), osteoclacin (OC), bone morphogenic protein-2 (BMP-2) as an important factor for bone formation, and mineralization. The present review can provide new insights in the osteoblastic differentiation of marine natural products and possibility for their application in bone health supplement.

• Journal of Physiology & Pathology in Korean Medicine
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• v.28 no.1
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• pp.29-34
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• 2014

Bone homeostasis is maintained by balance between bone resorbing-osteoclasts and bone forming-osteoblasts. Excessive osteoclastic bone resorption plays a critical role in bone destruction in pathological bone diseases such as osteoporosis, rheumatoid arthritis, and periodontal disease. Many compounds derived from natural products have pharmacological applications and have therapeutic value for treating or preventing several bone diseases characterized by excessive bone resorption. To discover new compounds that can act as anti-resorptive agents, we screened for natural compounds that regulate osteclast differentiation, and found that water extract of Ziziphus Jujuba Mill (WEZJ) has inhibitory effects on osteoclast differentiation. In this study, WEZJ clearly inhibits the osteoclast differentiation in the presence of receptor activator of nuclear factor kB (RANKL), macrophage colony-stimulating factor (M-CSF) without cytoxicity by blocking activation of nuclear factor of activated T cells (NFAT)c1, and c-Fos. In signaling pathway, the phosphorylation of Akt, p38, c-Jun N-terminal kinases (JNK), extracellular signal-regulated kinases (ERK) and the expression of osteoclast-associated receptor (OSCAR), tartrate-resistant acid phosphates (TRAP), Integrin av, Integrin b3, Cathepsin K are suppressed, too. These result suggest that WEZJ may have therapeutic value for treating or preventing several bone diseases characterized by excessive bone destruction.

• Food Science and Biotechnology
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• v.14 no.1
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• pp.94-98
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• 2005

Bone resorption surrounding tooth root causes tooth loss in periodontitis patients. Osteoclast has bone resorption activity. Effects of Artemisia asiatica on bone resorption induced by periodontopathogens, Porphyromonas gingivalis and Treponema denticola, were examined using co-culture systems of mouse osteoblasts and bone marrow cells. Addition of A. asiatica ethanol extract to bacterial sonicate abolished bacteria-induced osteoclastogenesis. To determine inhibitory mechanism of A. asiatica against osteoclastogenesis, effects of A. asiatica on expressions of osteoclastogenesis-inducing factors such as receptor activator of NF-${\kappa}B$ ligand (RANKL), prostaglandin $E_2\;(PGE_2)$, interleukin (IL)-1, and tumor necrosis factor (TNF)-${\alpha}$, in osteoblasts were examined. A. asiatica suppressed expressions of RANKL, $PGE_2$, IL-$1{\beta}$, and TNF-${\alpha}$ increased by each bacterial sonicate. These results suggest inhibitory action of A. asiatica against osteoclastogenesis is associated with down-regulations of RANKL, $PGE_2$ IL-$1{\beta}$, and TNF-${\alpha}$ expressions.

• Journal of Periodontal and Implant Science
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• v.32 no.4
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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.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.33 no.4
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• pp.381-385
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• 2007

Bone is a dynamic organ that bone remodeling occurs throughout life and involves the process in which the bone matrix is broken down through resorption by osteoclasts and then built back again through bone formation by osteoblasts. Usually these two processes balance each other and a stable level of bone mass is maintained. We here discuss transcription factors involved in regulating the osteoblast differentiation pathway. Runx2 is a transcription factor which is essential in skeletal development by regulating osteoblast differentiation and chondrocyte maturation. Its companion subunit, Cbf${\beta}$ is needed for an early step in osteoblast differentiation pathway. Whereas Osterix(Osx) is a new identified osteoblast-specific transcription factor which is required for the differentiation of preosteoblasts into more mature and functional osteoblasts. We also discuss other transcription factors, Msx1 and 2, Dlx5 and 6, Twist, and Sp3 that affect skeletal patterning and development. Understanding the characteristics of mice in which these transcription factors are inactivated should help define their role in bone physiology and pathology of bone defects.

• Journal of Life Science
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• v.28 no.7
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• pp.874-883
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• 2018

Osteoporosis is a disease that increases the risk of fracture by decreasing the mass and strength of bone. It is caused by imbalance of osteoclast bone formation and osteoclast bone resorption. Bone formation by osteoblast is activated via bone morphogenetic proteins and runt-related transcription factor 2. $Wnt/{\beta}-catenin$ signaling and bone resorption by osteoclast are initiated by the binding of receptor activator of nuclear $factor-{\kappa}B$ ligand and receptor activator of nuclear $factor-{\kappa}B$. Menopausal women are at risk for many diseases due to hormonal imbalances, and osteoporosis is the most common metabolic disorder in 30% of postmenopausal women. When estrogen is deficient, bone resorption of osteoclasts is promoted, and the risk of osteoporosis especially increases in postmenopausal women. Hormone replacement therapy has been widely used to relieve or treat the symptoms of menopausal syndrome. However, long-term administration of hormone therapy has been associated with a high risk of side effects, such as breast cancer, ovarian cancer, and uterine cancer. Recently, phytochemicals have been actively studied as a phytoestrogen, which has an estrogen-like activity to cope with symptoms of menopausal syndrome. Therefore, in this review, we investigated the differentiation mechanism of osteoblast and osteoclast and the role of estrogen and phytoestrogen in bone metabolism in relation to previous studies.

• Journal of Oral Medicine and Pain
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• v.25 no.1
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• pp.53-62
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• 2000

Bone marrow culture systems are widely used to differentiate osteoclast-like cells in vitro using several osteotropic hormones. In this study, we isolated and cultured the mouse bone marrow cells with or without some osteotropic hormones such as parathyroid hormone(PTH), prostaglandin $E_2(PGE_2)$ and $l,25(OH)_2-vitamin$ $D_3$(Vit. $D_3$). We confirmed the formation of osteoclast-like cells morphologically and functionally by the expression of tartrate-resistant acid phosphatase(TRAP) and by their capability to resorb dentin slices. We also studied the effects of transforming growth $factor-{\beta}(TGF-{\beta})$ and epidermal growth factor(EGF) on the Vit. $D_3-induced$ osteoclast-like cell formation. In control, a few multinucleated cells were formed whereas PTH and $PGE_2$ increased the number of multinucleated cells. PTH, $PGE_2$ and Vit. $D_3$ induced the formation of TRAP-positive multinucleated cells. After culture of mouse bone marrow cells on the dentin slices with or without osteotropic hormones, giant cells with diverse morphology were found on the dentin slices under the scanning electronmicroscopy. After removing the attached cells, resorption pits were identified on the dentin slices, and the shape of resorption pits was variable. EGF increased the osteoclast-like cell formation induced by Vit. $D_3$, however, $TGF-{\beta}$ showed biphasic effect, which at low concentration, increased and at high concentration, decreased the osteoclast-like cell formation induced by Vit. $D_3$.

• The Journal of Korean Academy of Prosthodontics
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• v.50 no.2
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• pp.99-105
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• 2012

Purpose: The change of the marginal bone around dental implants have significance not only for the functional maintenance but also for the esthetic success of the implant. The purpose of this study was to investigate the load transfer of internal conical joint type implant according to marginal bone resorption by using the three-dimensional finite element analysis model. Materials and methods: The internal conical joint type system was selected as an experimental model. Finite element models of bone/implant/prosthesis complex were constructed. A load of 300 N was applied vertically beside 3 mm of implant axis. Results: The pattern of stress distribution according to marginal bone resorption was similar. The maximum equivalent stress of implant was increase according to marginal bone resorption and the largest maximum equivalent stress was shown at model of 1 mm marginal bone resorption. Although marginal bone loss more than 1mm was occurred increasing of stress, the width of the stress increase was decreasing. Conclusion: According to these results, the exposure of thin neck portion of internal conical joint type implant is most important factor in stress increasing.

• The korean journal of orthodontics
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• v.50 no.3
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• pp.216-226
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• 2020

Root resorption can be caused by several factors, including contact with the cortical bone. Here we report a case involving a 21-year-old female with Angle Class II, division 1 malocclusion who exhibited significant root resorption in the maxillary right central incisor after orthodontic treatment. The patient presented with significant left-sided deviation of the maxillary incisors due to lingual dislocation of the left lateral incisor and a Class II molar relationship. Cephalometric analysis demonstrated a Class I skeletal relationship (A point-nasion-B point, 2.5°) and proclined maxillary anterior teeth (upper incisor to sella-nasion plane angle, 113.4°). The primary treatment objectives were the achievement of stable occlusion with midline agreement between the maxillary and mandibular dentitions and appropriate maxillary anterior tooth axes and molar relationship. A panoramic radiograph obtained after active treatment showed significant root resorption in the maxillary right central incisor; therefore, we performed cone-beam computed tomography, which confirmed root resorption along the cortical bone around the incisive canal. The findings from this case, where different degrees of root resorption were observed despite comparable degrees of orthodontic movement in the bilateral maxillary central incisors, suggest that the incisive canal could be an inducing factor for root resorption. However, further investigation is necessary to confirm this assumption.

• The Korean Journal of Oral and Maxillofacial Pathology
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• v.41 no.4
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• pp.155-162
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• 2017

Connective tissue growth factor (CTGF, CCN2) is one of the multi-functional secreted proteins which belong to CCN family of cysteine-rich growth factors. CTGF is known to have pivotal roles in embryonic endochondral ossification but its role in relevance to periodontitis is never been determined. To identify new molecular mediators associated with periodontitis-induced bone resorption, we have analyzed publicly available GEO database and found the markedly augmented CTGF mRNA expression in periodontitis gingival tissues. The existence of CTGF significantly enhanced mature osteoclasts survival which accompanied by reduction in TUNEL-positive nuclei and PARP cleavage. These results may provide another line of evidence the CTGF mediated prolonged osteoclast survival and subsequent increased bone resorption in the periodontitis patients.