• 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.

• Imaging Science in Dentistry
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• v.34 no.3
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• pp.137-144
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• 2004

Purpose: To investigate the effects of low dose irradiation on the calcium content and calcific nodule formation of the MC3T3-El osteoblastic cell line. Materials and Methods: Cells were irradiated with a single dose of 0.2, 0.4 and 0.6 Gy at a dose rate of 5.38 Gy/min using Cs-137 irradiator. After irradiation, the calcium content and calcific nodule formation were examined on the 1st, 2nd, 3rd and 4th week. Results: We did not find any significant difference of total calcium content after irradiation of 0.2, 0.4 and 0.6 Gy when compared with the unirradiated control group. There was no significant difference of total calcium content between 0.2, 0.4 and 0.6 Gy irradiated groups. We found an increased tendency of the calcific nodule formation after irradiation of 0.2, 0.4 and 0.6 Gy when compared with the unirradiated control group without significant difference of calcific nodule formation between 0.2, 0.4 and 0.6 Gy irradiated groups. Conclusion : The results showed an increased tendency of the calcific nodule formation after low dose irradiation. However, this tendency did not increase with the increase of irradiation dose.

• 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.

• Imaging Science in Dentistry
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• v.33 no.3
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• pp.179-185
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• 2003

Purpose: To investigate the effects of irradiation on the phenotypic expression of the MC3T3-El osteoblastic cell line, particularly on the expression of osteocalcin and osteopontin. Materials and Methods: Cells were irradiated with a single dose of 0.5, 1,4, and 8 Gy at a dose rate of 5.38 Gy/min using a cesium 137 irradiator. After the specimens were harvested, RNA was extracted on the 3rd, 7th, 14th, and 21st day after irradiation. The RNA strands were reverse-transcribed and the resulting cDNAs were subjected to amplification by PCR. Results: The irradiated cells demonstrated a dose-dependent increase in osteocalcin and a dose-dependent decrease in osteopontin mRNA expression compared with the non-irradiated control group, The amount of osteocalcin mRNA expression decreased significantly at the 3rd day after irradiation of 0,5, 1,4, and 8 Gy, and also decreased significantly at the 3rd, 14th, and 21 st day after irradiation in the 8 Gy exposed group compared with the control group, The degree of osteopontin mRNA expression increased significantly at the 7th day after irradiation of 0,5, 1,4, and 8Gy, Conclusion: These results showed that each single dose of 0,5, 1, 4, and 8 Gy influenced the mRNA expression of osteocalcin and osteopontin associated with the calcification stage of osteoblastic cells, suggesting that each single dose affected bone formation at the cell level.

• 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.

• International journal of thyroidology
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• v.10 no.2
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• pp.71-76
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• 2017

Background and Objectives: The role of thyroid-stimulating hormone (TSH) signaling on osteoblastic differentiation is still undetermined. The aim of this study was to investigate the effects of 5-aza-2'-deoxycytidine (5-azacytidine) on TSH-mediated regulations of osteoblasts. Materials and Methods: MG63, a human osteoblastic cell-line, was treated with 5-azacytidine before inducing osteogenic differentiation using osteogenic medium (OM) containing L-ascorbic acid and ${\beta}$-glyceophosphate. Bovine TSH or monoclonal TSH receptor stimulating antibody (TSAb) was treated. Quantitative real-time PCR analyses or measurement of alkaline phosphatase activities were performed for evaluating osteoblastic differentiation. Results: Studies for osteogenic-related genes or alkaline phosphatase activity demonstrated that treatment of TSH or TSAb alone had no effects on osteoblastic differentiation in MG63 cells. However, treatment of 5-azacytidine, per se, significantly increased osteoblastic differentiation and combination treatment of 5-azacytidine and TSH or TSAb in the condition of OM showed further significant increase of osteoblastic differentiation. Conclusion: Stimulating TSH signaling has little effects on osteoblastic differentiation in vitro. However, in the condition of epigenetic modification using inhibitor of DNA methylation, TSH signaling positively affects osteoblastic differentiation in human osteoblasts.

• 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.

• Imaging Science in Dentistry
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• v.35 no.1
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• pp.1-8
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• 2005

Purpose : To investigate the effects of irradiation on the calcium content and calcific nodule formation in the MC3T3-E1 osteoblastic cell line. Materials and Methods : Cells were irradiated with a single dose of 2,4 and 8 Gy at a dose rate of 5.38 Gy/min using a Cs-137 irradiator. After irradiation, the calcium content and calcific nodule formation were examined on the 1 st, 2nd, 3rd and 4th week. Results : A decreasing dose-dependent tendency of the cell proliferation rate was found in all irradiated groups of this experiment when compared with the unirradiated control group. In accordance with the duration of culture, there was no significant difference in the cell proliferation rate after irradiation of 2 Gy when compared with the unirradiated group, however a decreasing tendency was found in 4 Gy- and 8 Gy-irradiated groups. While an increase in total calcium content after irradiation of 2 Gy was found at week 1, week 2, and week 4, there was a decrease in calcium content at week 1 through 4 in the 8 Gy- irradiated group. Calcific nodule formation was increased in irradiated experimental groups when compared with the unirradiated control group in the 2 Gy-irradiated group, but decreased in the 4 Gy- and 8 Gy-irradiated groups at the same stage. Conclusion : The results showed a mild increasing tendency of the calcific nodule formation after irradiation of 2 Gy. However, a decreased calcific nodule formation in 4 Gy- and 8 Gy-irradiated groups was found. Taken together, the irradiation of 2 Gy mildly activated bone formation, however 4 Gy or 8 Gy suppressed bone formation by decreasing cell numbers in the MC3T3-El osteoblastic cell line.

• Imaging Science in Dentistry
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• v.34 no.2
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• pp.99-106
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• 2004

Purpose: To investigate the effects of irradiation on the phenotypic expression of the MC3T3-El osteoblastic cell line, especially on the osteonectin and bone sialoprotein. Materials and Methods: Cells were irradiated with a single dose of 0.5, 1, 4 and 8 Gy at a dose rate of 5.38 Gy/min using Cs-I37 irradiator. After specimens were harvested, total RNA was extracted on the 3rd, 7th, 14th, 21st day after irradiation. The total RNA was reverse-transcribed and the resulting cDNAs were subjected to amplification by PCR with a pair of primers. Results: The irradiated cells showed a dose-dependent increase in osteonectin mRNA expression when compared with the unirradiated control group. The irradiated cells showed no difference in bone sialoprotein mRNA expression when compared with the unirradiated control group. In accordance with the duration of culture period after irradiation, the level of osteonectin mRNA expression showed no difference, but it increased a little at the 21st day in the 4 and 8 Gy exposure groups. In the case of bone sialoprotein, however, the level of mRNA expression increased significantly at the 3rd and 7th day after irradiation, but it showed no difference at the 14th and 21st day when compared with the control group. Conclusion: These results showed that each single dose of 0.5, 1, 4 and 8 Gy influenced the mRNA expression of osteonectin and bone sialoprotein at the calcification stage of osteoblastic cells, suggesting that single dose of irradiation affected the osteoblastic bone formation at the cell level.