• Journal of Integrative Natural Science
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• v.9 no.3
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• pp.171-176
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• 2016

Rap1 is a key regulator of cell adhesion and migration. Although increasing evidence indicates that the Rap1 signaling pathway is involved in the process of bone remodeling, the mechanism by which Rap1 regulates osteoblastic differentiation and cell adhesion remains unknown. Here, we investigated the morphological characteristics and osteoblastic differentiation of cells expressing constitutively activated form of Rap1A (Rap1ACA) or Rap1 GTPase activating protein Rap1GAP and found that activated Rap1 induces osteoblastic differentiation and cell adhesion as well as cell spreading. When osteoblastic differentiation was induced, Rap1ACA cells showed considerably higher levels of calcium deposits than the wild-type and Rap1GAP-overexpressing cells did. Rap1ACA cells showed increased spreading and size, as well as strong cell adhesion and significantly decreased growth rates. F-actin staining using phalloidin revealed several thin thread-like filopodia around the protrusions in Rap1ACA cells, which possibly contribute to the increased cell adhesion.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.28 no.2
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• pp.127-135
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• 2006

Objectives: The extent of bone formation that occurs at the interface of metallic implants and bone is determined by the number and activity of osteoblastic cells. Stress proteins may be contributing determinants of cell viability in altered environments. Hsp27 is a small Mr hsp which is known as a molecular chaperone. Methods: To better understand how heat shock protein 27 contributes to endosseous implant - associated metal ions affects on osteoblastic cell viability, the effect of chromium and titanium ions were compared to effects of cadmium ions in the ROS17/2.8 osteoblastic cell line. Results: ROS17/2.8 osteoblastic cell line demonstrated ion - specific reductions in growth; reductions were significantly greater for cadmium than for chromium or titanium. Chromium impaired growth of cultures without altering cell viability measured using the MTT assay. A stable transformed cell line expressing additional hsp27(clone "A7") was resistant to the toxic effects of titanium and partially protected from cadmium toxicity. Conclusions: A role for hsp27 in protection of osteoblastic cells from metal ion toxicity is supported by the chromium - induced elevations in hsp27 abundance and the behavior of the A7 cell line in response to metal ions in culture. Similar biochemical responses to altered cellular environments may contribute to the fate of tissues adjacent to select metallic implants.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.37 no.3
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• pp.214-224
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• 2011

Objective: This study examined the potential of the in vitro osteogenesis of microtopographically modified surfaces, RBM (resorbable blasting media) surfaces, which generate hydroxyapatite grit-blasting. Methods: RBM surfaces were modified hydroxyapatite grit-blasting to produce microtopographically modified surfaces and the surface morphology, roughness or elements were examined. To investigate the potential of the in vitro osteogenesis, the osteoblastic cell adhesion, proliferation, and differentiation were examined using the human osteoblast-like cell line, MG-63 cells. Osteoblastic cell proliferation was examined as a function of time. In addition, osteoblastic cell differentiation was verified using four different methods of an ALP activity assay, a mineralization assay using alizarin red-s staining, and gene expression of osteoblastic differentiation marker using RT-PCR or ELISA. Results: Osteoblastic cell adhesion, proliferation and ALP activity was elevated on the RBM surfaces compared to the machined group. The cells exhibited a high level of gene expression of the osteoblastic differentiation makers (osteonectin, type I collagen, Runx-2, osterix). imilar data was represented in the ELISA produced similar results in that the RBM surface increased the level of osteocalcin, osteopontin, TGF-beta1 and PGE2 secretion, which was known to stimulate the osteogenesis. Moreover, alizarin red-s staining revealed significantly more mineralized nodules on the RBM surfaces than the machined discs. Conclusion: RBM surfaces modified with hydroxyapatite grit-blasting stimulate the in vitro osteogenesis of MG-63 cells and may accelerate bone formation and increase bone-implant contact.

• BMB Reports
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• v.48 no.10
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• pp.583-588
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• 2015

Microtubule actin crosslinking factor 1 (MACF1), a widely expressed cytoskeletal linker, plays important roles in various cells by regulating cytoskeleton dynamics. However, its role in osteoblastic cells is not well understood. Based on our previous findings that the association of MACF1 with F-actin and microtubules in osteoblast-like cells was altered under magnetic force conditions, here, by adopting a stable MACF1-knockdown MC3T3-E1 osteoblastic cell line, we found that MACF1 knockdown induced large cells with a binuclear/multinuclear structure. Further, immunofluorescence staining showed disorganization of F-actin and microtubules in MACF1-knockdown cells. Cell counting revealed significant decrease of cell proliferation and cell cycle analysis showed an S phase cell cycle arrest in MACF1-knockdown cells. Moreover and interestingly, MACF1 knockdown showed a potential effect on cellular MTT reduction activity and mitochondrial content, suggesting an impact on cellular metabolic activity. These results together indicate an important role of MACF1 in regulating osteoblastic cell morphology and function.

• Journal of the korean academy of Pediatric Dentistry
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• v.25 no.3
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• pp.635-648
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• 1998

The clinical use of fluoride with a well known osteogenic action in osteoporotic patients is rational, because this condition is characterized by impaired bone formation. However, its anabolic effect has not been demonstrated well in vitro. The purpose of this study was to investigate the effects of sodium fluoride on the physiological role of osteoblastic cell. Osteoblastic cells were isolated from fetal rat calvaria. The results were as follows : 1. Mineralized nodules were shown in osteoblastic cell cultures, which had been maintained in the presence of ascorbic acid and ${\beta}-glycerophosphate$ up to 21 days. When cultures were treated with pulses of 48 hr duration before apparent mineralization was occurring, 2-fold increased in their number was detected. 2. Alkaline phosphatase activity of osteoblastic cells was inhibited by sodium fluoride in dose dependent manner. 3. The effect of sodium fluoride on the osteoblastic cell proliferation was measured by the incorporation of $[^3H]$-thymidine into DNA. As a result, sodium fluoride at $1{\sim}100{\mu}M$ increased the $[^3H]$-thymidine incorporation into DNA in a dose dependent manner. 4. The signaling mechanism activated by sodium fluoride dose-dependently enhanced the tyrosine phosphorylation of the adaptor molecule $Shc^{p66}$ and their association with Grb2, one of earlier events in a MAP kinase activation pathway cascade used by a significant subset of G protein-coupled receptors. 5. The phosphorylation of CREB(cAMP response element binding protein)was inhibited by the sodium fluoride in MC3T3E1 cells. In conclusion, the results of this study suggested that the mitogenic effect of the sodium fluoride in MC3T3E1 cell was stimulated in a dose-dependent manner and suggested "an important role for the interaction between She and Grb2" in controlling the proliferation of osteoblasts.

• Journal of Acupuncture Research
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• v.19 no.5
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• pp.136-148
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• 2002

본 연구는 osteoblastic cells에서 estogen 의 생합성을 유도하는 aromatase의 activity에 대한 봉독(蜂毒)작용을 측정하여, 봉독치료시 Arthritis의 진행 억제 및 estogen의 의한 bone formation의 효과여부를 검증하기 위해 실행하였다. 사용된 세포주로는 Osteoblastic phenotype으로 분화가 유도되는 Human leukaemic cell line FLG 29.1 및 the primary first-passage osteoblastic cells (hOB cells)이며, 이들을 각각 배양하고 각각의 RNA를 isolation한 뒤 PCR 증폭을 하였다. Aromatase에 대한 활성인자인 TPA와 TGF-${\beta}1$ 및 봉독을 이용하여 aromatase의 expression 및 activity에 대해 미치는 영향을 측정한 바, aromatase expression은 FLG 29.1 cell와 hoB cells에서, 50nM TPA 24시간 처리, 봉독 2 ~ 4시간 처리와 TGF-${\beta}1$ 3시간 처리로 유도한 결과 TPA와 TGF-${\beta}1$의 경우는 서로 유사하였고, 봉독에서 상대적으로 높게 나타났다. Aromatase activity는 FLG 29.1 cell, hoB cells에서 24시간 incubation한 결과, 모든 실험에서 일정하게 선상증가를 보였다. $5{\mu}{\ell}/m{\ell}$ BV에서 TPA와 TGF-${\beta}1$보다 뚜렷하게 증가하였으며, 0.5mM Bt2-cAMP, 50nM dexametasone처리에서는 유의성이 없었다. Estrogen 생합성을 촉매하는 aromatase activity BV가 처리에서 현저하게 증가하였기에, Rheumatis arthritis의 bone destruction에 대해 BV가 효과적인 역할을 할 것으로 보여진다.

• Journal of Society of Preventive Korean Medicine
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• v.10 no.2
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• pp.19-30
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• 2006

It is well known that glucocorticoid may induce osteoporosis as its side effect in long-term therapy. The inhibition of osteoblast by glucocorticoid is also recognized as its action mechanism of decreased bone formation. In this study, the effect of DSG, Danchisoyosangamibang, on the differentiation and function of osteoblastic cells was investigated. The osteoblastic cells were isolated from rat calvariae using collagenase treatment. The cell counting, enzyme activity assay, MTT assay, collagen content assay were done to determine the cell proliferation, intracellular alkaline phosphatase (ALP) activity, bone martrix production, and cell apoptosis. DSG enhanced the cell proliferation after the culture for 10 days. ALP activity and total protein synthesis, and intracelluar collagen synthesis were increased time dependently when the cells were treated with DSG in the presence of dexamethasone. And, DSG restored calvarial cell function decreased by dexamethasone.

• Journal of Nutrition and Health
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• v.51 no.4
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• pp.316-322
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• 2018

Purpose: The Glycyrrhiza uralensis species (Leguminosae) as a medicinal biocompound, and one of its root components, isoliquritigenin (ISL), which is a flavonoid, has been reported to have anti-tumor activity in vitro and in vivo. However, its function in bone formation has not been studied yet. In this study, we tested the effect of Glycyrrhiza uralensis (ErLR) and baked Glycyrrhiza uralensis (EdLR) extracts on osteoblast proliferation, alkaline phosphatase (ALP) activity, and bone-related gene expression in osteoblastic MC3T3-E1 cells. Methods: MC3T3-E1 cells were cultured in various levels of ErLR (0, 5, 10, 15, $20{\mu}g/mL$), EdLR (0, 5, 10, 15, $20{\mu}g/mL$), or ISL (0, 5, 10, 15, $20{\mu}M$) in time sequences (1, 5, and 20 days). Also, isoliquritigenin (ISL) was tested for comparison to those two biocompound extracts. Results: MTT assay results showed that all three compounds (ErLR, EdLR, and ISL) increased osteoblastic-cell proliferation in a concentration-dependent manner for one day. In addition, both ErLR and EdLR compounds elevated the osteoblast proliferation for 5 or 20 days. Extracellular ALP activity was also increased as ErLR, EdLR, and ISL concentration increased at 20 days, which implies the positive effect of Glycyrrhiza species on osteoblast mineralization. The bone-related marker mRNAs were upregulated in the ErLR-treated osteoblastic MC3T3-E1 cells for 20 days. Bone-specific transcription factor Runx2 gene expression was also elevated in the ErLR- and EdLR-treated osteoblastic MC3T3-E1 cells for 20 days. Conclusion: These results demonstrated that Glycyrrhiza uralensis extracts may be useful for preventing osteoporosis by increasing cell proliferation, ALP activity, and bone-marker gene expression in osteoblastic cells.

• Journal of Periodontal and Implant Science
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• v.29 no.4
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• pp.785-804
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• 1999

The cell activities of bone metabolism is affected by growth factor rather than by hormone. The affects of growth factors on the bone activity were observed using various culture methods. Platelet-derived growth factor(PDGF) is produced from the well differentiated bone cell. It stimulates cell mitosis, synthesizes collagen in bone tissue and plays a role in healing response. The purpose of this study is to evaluate the effects that PDGF has on the activity and the proliferation of osteoblast by measuring the activity of alkaline phosphatase, the growth formation of calcified nodules, and osteocalcin production. In this study, HOS and ROS 17/2.8 osteoblastic cell line was used, along with variable concentrations of PDGF the were measured with osteoblastic proliferation. The cell proliferation of HOS and ROS 17/2.8 cells was stimulated dose- depentdently. Alakline phosphatase activity was significantly decreased by PDGF in osteoblastic cells. A number of small calcified nodules were observed in HOS cell treated with low concentrations(0.1, 0.4 ng/ml) of PDGF-BB and no significant difference from control group was found. High concentrations(10, 50 ng/ml) of PDGF suppressed calcified nodule formation. And osteocalcin production was inhibited with PDGF. These results suggest that PDGF stimulates the osteoblastic proliferation, whereas suppresses the individual cellular functions.

• Restorative Dentistry and Endodontics
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• v.22 no.1
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• pp.305-324
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• 1997

Numerous materials such as amalgam, IRM, SuperEBA, dessicated ZOE, and Ketac-Silver have been used as a root-end filling material or to repair furcation perforations. But so far no material has been found to satisfy all of the requirements of an ideal restorative material. Recently, mineral trioxide aggregate (MTA) has been suggested for use as a root end filling material and for the repair of furcation perforations. The purpose of this study was to compare the effect of MTA on the proliferation of MC3T3/E1 osteoblastic cell, formation of bone nodule, alkaline phosphatase activity, and finally the tissue reaction of bone with those of amalgam, IRM, SuperEBA, dessicated ZOE, and Ketac-Silver. The following conclusions were drawn within the limits of the experimental results : 1. MTA showed a excellent proliferation of osteoblastic cell and Ketac-Silver showed moderate proliferation of osteoblastic cell. The rest of test materials showed no proliferation of osteoblastic cell. 2. Many of definite bone nodules were found in the MTA group. In contrast, Ketac-Silver group showed no definite bone formation but only showed mild sign of bone formation. 3. Alkaline phosphatase activity of Ketac-Silver and MTA showed similar results. But both of them showed higher activity than that of other materials (p<0.005). 4. The tissue reaction to implanted MTA in the calbarium of mouse was milder than that observed with other materials. The tissue reaction of dessicated ZOE showed the worst results among the test materials.