• Journal of Periodontal and Implant Science
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• 제30권2호
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• pp.389-405
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• 2000

The purpose of this study is to evaluate the effect of IGF-I for DNA synthetic activity and the mRNA expression of bone matrix protein, type I collagen and osteopontin in prolifetation and differentiation of MC3T3-E1 cells. To evaluate DNA synthetic activity, cells were seeded at $2{\times}10^4cells/ml$ in 24 well plates and to evaluate mRNA of type I collagen and osteopontin cells were seeded at $5{\times}10^5cells/ml$ in 100mm culture dishes. These cells were cultured in alpha-minimum essential medium(${\alpha}-MEM$) containing 10% fetal bovine serum at $37^{\circ}C$, 5% $CO_2$ incubator. For DNA synthetic activity test 1, 10, 100ng/ml IGF-I were added to the cells which had been cultured for 3 days before 24 hours. For type I collagen mRNA expression 1, 10ng/ml IGF-I were added to the cells which had been cultured for 5, 10 days and for osteopontin mRNA expression 0.1, 1, 10ng/ml IGF-I were added to the cells which had been cultured for 5, 15, 20 days. Cell proliferaton was measured by the incorporation of [$^3H$]-thymidine into DNA and expression for type I collagen and osteopontin were measured by northern blot analysis. The results were as follows : DNA synthetic activity were generally higher in experimental group than control group. Expressions of type I collagen mRNA were higher at 5 day group and much lower at 10 day group in the control groups. In the experimental groups, mRNA expressions were slightly increased when 1 ng/ml IGF-I were added to 5 day group and decreased in all experimental 10 day groups. Expressions of osteopontin mRNA were higher at 20 day groups and lower at 15 day groups than the control groups. In the experimental groups, mRNA expressions were incereased when 0.1, 1 ng/ml IGF-I were added to 5 day group and in all the 15 day groups, but decreased when 0.1, 1, 10 ng/ml IGF-I were added to 20 day groups. IGF-I stimulated DNA synthetic activity of MC3T3-E1 cells during proliferation stage significantly, did not greatly changed effects on type I collagen mRNA expression and stimulated osteopontin mRNA expression at 15 day especially. In conclusion, we suggests that IGF-I have a tendency of stimulation effect of DNA synthetic activity but do not stimulate type I collagen mRNA in proliferation stage of MC3T3-E1 cell cultures, and stimulate osteopontin mRNA in differentiation stage of MC3T3-E1 cell cultures.

• Imaging Science in Dentistry
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• 제35권1호
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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.

• Journal of Periodontal and Implant Science
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• 제38권sup2호
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• pp.299-308
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• 2008

Purpose: The aim of this study was to evaluate adhesion and gene expression of the MC3T3-E1 cells cultured on machined titanium surface (MS) and anodized titanium surface (AS) using MTT test, Scanning electron micrograph and cDNA microarray. Materials and Methods: The MTT test assay was used for examining the proliferation of MC3T3-E1 cells, osteoblast like cells from Rat calvaria, on MS and AS for 24 hours and 48 hours. Cell cultures were incubated for 24 hours to evaluate the influence of the substrate geometry on both surfaces using a Scanning Electron Micrograph (SEM). The cDNA microarray Agilent Rat 22K chip was used to monitor expressions of genes. Results: After 24 hours of adhesion, the cell density on AS was higher than MS (p < 0.05). After 48 hours the cell density on both titanium surfaces were similar (p > 0.05). AS had the irregular, rough and porous surface texture. After 48 hours incubation of the MC3T3-E1 cells, connective tissue growth factor (CTGF) was up-regulated on AS than MS (more than 2 fold) and the insulin-like growth factor 1 receptor was down-regulated (more than 2 fold) on AS than MS. Conclusion: Microarray assay at 48 hours after culturing the cells on both surfaces revealed that osteoinductive molecules appeared more prominent on AS, whereas the adhesion molecules on the biomaterial were higher on MS than AS, which will affect the phenotype of the plated cells depending on the surface morphology.

• Journal of Periodontal and Implant Science
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• 제27권4호
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• pp.669-684
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• 1997

Polypeptide growth factors belong to a class of potent biologic mediators which regulate cell differentiation, proliferation, migration and metabolism. IGF-I is polypeptides secreted by skeletal cells and is considered as regulators of bone formation. The purpose of this study is to evaluate the effects of IGF-I on bone nodule formation and alkaline phosphatase activity of MC3T3-E1 cells. MC3T3-E1 cells were seeded at $1{\times}10^4$ cells/well, $1{\times}10^5$ cells/well in alpha-modified Eagle medium containing 10% fetal bovine serum, 10 mM ${\beta}-glycerophosphate$ and $5O{\mu}g/ml$ of ascorbic acid. Before 48 hours of indicated time, medium were changed with serum free medium. After 24 hours, 0.1, 1, 10 ng/ml IGF-I were added to the cells and cultured for 3, 7, 14, 21, 28 days. And histochemical analysis was done and ALP activity was measured and was expressed as nmol/min/mg of protein. The bone nodule formation in MC3T3-E1 cells of IGF-I was seen at 21, 28 days, but there were no difference between control group and experimental groups. The ALP activity decreased when it is compare to control 2 group except for 1 ng/ml, 10 ng/ml IGF-I of 21-day-groups and 1 ng/ml IGF-I of 28-day-groups. Dose response effects of IGF-I of ALP activity in MC3T3-E1 cells were seen the highest ALP activity at 1ng/ml until 21days and the highest ALP activity at 10 ng/ml of 28 daygroups. The peak times were seen at 7-day group, 14-day group on control group and experimental group respectively, and 1 ng/ml group was the highest ALP activity, From the above results, IGF-I was not seen notable effect on bone nodule formation and decreased ALP activity of MC3T3-E1 cells but the use of IGF-I to mediate biological stimulation of MC3T3-E1 cells shows promise for future therapeutic application.

• Imaging Science in Dentistry
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• 제34권3호
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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 the Korean Association of Oral and Maxillofacial Surgeons
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• 제33권6호
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• pp.617-624
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• 2007

Insulin-like growth factor(IGF) is the most abundant growth factor in bone matrix. Recent studies have shown that it can sensitize apoptotic cell death of osteoblasts. Thus, this study investigated whether IGF-II aggravates irradiation-induced cell death of osteoblasts. Cultured MC3T3 osteoblasts were irradiated and IGF-II was added at the concentration of 50 ng/ml immediately after the irradiation. Cell viability was measured by MTT assay. Changes in cell death and cell cycle were analyzed by flow cytometry. The expression of proapoptotic gene bax and antiapoptotic gene bcl-2 was quantified by real time RT-PCR and Western blot. A dose of 30 Gy caused G2/M arrest and increased cell death through both necrosis and apoptosis, while irradiation from 4 to 10 Gy little affected cell cycle and death. IGF-II treatment reduced cell viability without stimulating cell proliferation and changing cell cycle. Combined treatment of IGF-II with irradiation decreased cell viability and proliferation and increased cell death along with G2/M arrest. These effects were not different from those of irradiation only. At transcriptional and protein levels, IGF-II treatment did not affect bax and bcl-2 expression, whereas irradiation increased the expression ofbax without changes in bcl-2. IGF-II in combination with irradiation showed similar findings. These results suggest that IGF-II could modulate apoptotic cell death through mechanisms other than an imbalance between bax and bcl-2 gene expression, although its effect was overridden by irradiation.

• Journal of Periodontal and Implant Science
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• 제30권1호
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• pp.39-52
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• 2000

Polypeptide growth factor belong to a class of potent biologic mediator which regulate cell differentiation, proliferation, migration and metabolism. 1,25-dihydroxyvitamin $D_3$ decrease cell proliferation, and stimulate alkaline phosphatase activity which express in osteoblast during cell differentiation period. IGF-I is known to stimulate cell proliferation and differentiation too. 1,25-dihydroxyvitamin $D_3$ is known to increase IGF-I binding sites and IGF binding protein which inhibite the effect of IGF. The purpose of this study is to evaluate potential role of IGF-I as mediator that control the action of 1,25-dihydroxyvitamin $D_3$. MC3T3-E1 cell were seeded $5{\times}10^5/ml$ at 100mm culture plate in ${\alpha}-MEM$ containing 10% fetal bovine serum. After 48 hour incubation period, medium were changed ${\alpha}-MEM$ containing 5% fetal bovine serum. After 24 hours, $10^{-9}M$ 1,25-dihydroxyvitamin $D_3$ added. Total mRNA was extracted at 0, 6, 24, 48, 72 hour. PRPCR method was programed for the detection of IGF-I mRNA. In the both groups of 1,25-dihydroxy vitamin $D_3$ treated and control, alternative splicing form of IGF-I, IGF-IA and IGF-IB were expressed. In the 1,25-dihydroxyvitamin $D_3$ treated group, IGF-I mRNA expression was matained until 24 hour, there after expression was decresed. MC3T3-E1 cell were seeded $2.5{\times}10^4/ml$ at 24well plate in ${\alpha}-MEM$ containing 10% fetal bovine serum. After 48 hour incubation period, medium were changed ${\alpha}-MEM$ containing 3% fetal bovine serum. After 24 hours, $10^{-9}M$ 1,25-dihydroxyvitamin $D_3$ and 10 ng/ml IGF-I were added separately or together. Cell were cultured for 1 and 3 days, $2{\mu}Ci/ml\;[^3H]$ -thymidine was added for the last 24h of culture of each days. ${[^3H]}$-thymidine incorporation in to DNA was measured and expressed counter per minute(CPM). DNA synthetic activity was significantly decreased by 1,25-dihydroxyvitamin $D_3$ both at 1 day and 3 day, and in the combination group of 1,25-dihydroxyvitamin $D_3$ and IGF-I, DNA synthetic activity was also decreased both at 1 day and 3 days. IGF-I did not affect the DNA synthetic activity compared to control group both at 1 day and 3 day. From the above results, 1,25-dihydroxyvitamin $D_3$ was potent inhibitor of cell proliferaton in MC3T3-E1 cells. It assumed that the effect of 1,25-dihydroxyvitamin $D_3$ on osteoblast proliferation may be mediated in part by decreased level of IGF-I.

• 대한치과교정학회지
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• 제28권1호
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• pp.155-163
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• 1998

정자기장이 MC3T3-E1 세포의 골생성능력에 어떠한 영향을 미치는지 알아보기 위하여 MC3T3-E1 세포를 4well 세포배양접시에 $SmCo_5$ 영구자석을 이용하여 76.4mT의 정자기장을 가한 상태에서 5일, 7일, 11일, 15일 및 21일간 배양한 후 세포의 ALP 활성도를 측정하고 Alizarin red S 염색을 통하여 골결절양상을 관찰하여 다음과 같은 결과를 얻었다. $\cdot$정자기장을 가한 군중 7일군, 11일군 및 15일군에서 MC3T3-E1세포의 ALP활성도가 대조군에 비해 낮게 나타났으며 (p<0.01) 그중 11일군에서 가장 억제효과가 많았다. $\cdot$Alizarin red S 염색을 통한 골결절 양상은 11일군까지는 실험군과 대조군 모두에서 염색양상이 나타나지 않았고 15일군에서 대조군은 소량의 골결절이 염색되었으며 실험군은 골결절 염색이 되지 않았으며 21일군에서는실험군과 대조군 모두에서 골결절이 염색되었으나 대조군에서 약간 더 염색된 양상을 나타내었다.

• Imaging Science in Dentistry
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• 제36권4호
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• pp.189-198
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• 2006

Purpose: To investigate the in vitro response of MC3T3-E1 osteoblastic cells to X-ray in the presence and absence of 2 deoxy-D-glucose (2-DG) and quercetin (QCT). Materials and Methods: The MC3T3-E1 cells were cultured in an ${\alpha}-MEM$ supplemented with 5 mM 2-DG or $10{\mu}M$ QCT and then the cells were incubated for 12 h prior to irradiation with 2, 4, 6, and 8Gy using a linear accelerator (Mevaprimus, Germany) delivered at a rate of 1.5 Gy/min. At various times after the irradiation, the cells were processed for the analyses of proliferation, viability, cytotoxicity, and mineralization. Results: Exposure of the cells to X-ray inhibited the tritium incorporation, 3-(4, 5-dimethylthiazol-2yl-)-2, 5-diphenyl tetrazolium bromide (MTT)-reducing activity, and alkaline phosphatase (ALP) activity, and caused cytotoxicity and apoptosis in a dose-dependent manner of the X-ray. This effect was further apparent on day 3 and 7 after the irradiation. RA+2-DG showed the decrease of DNA content, cell viability, and increase of cytotoxicity rather than RA. ALP activity increased on day 7 and subsequently its activity dropped to a lower level. 2-DG suppressed the calcium concentration, but visual difference of number of calcified nodules between RA and RA+2-DG was not noticed. RA+QCT showed the increase of DNA content, cell viability, but decrease of cytotoxicity and subG1 stage cells in the cell cycle, and increased calcified nodules in von Kossa staining rather than the RA. ALP activity showed significant increases on day 7 and subsequently its activity dropped to a lower level. Conclusion: The results showed that the 2-DG acted as a radiosensitizing agent and QCT acted as a radiosensitizing agent respectively in the irradiated MC3T3-E1 osteoblast-like cells.

• 생명과학회지
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• 제16권6호
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• pp.925-931
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• 2006

골조직은 골아세포, 파골세포, 골세포 등으로 구성되며, 골개조시 여러 인자가 세포증식, 분화, 활성화 및 골대사 조절에 관여한다. 이때 조골세포의 활성은 골형성에 중요하므로, 본 연구에서는 MC3T3-E1 조골세포주를 이용하여 해조류로 조제한 알칼리의 ENA-A 이온수가 조골세포의 증식과 분화활성에 미치는 영향을 조사하였다. 먼저 ENA-A 이온수가 조골세포의 성장에 미치는 영향을 MTT 검색법으로 조사 한 결과, ENA-A 이온수 2% 처리시 대조군과 비교하여 134% 증가하여 조골세포에 대해 높은 성장률을 보였다. 또한 ALP 효소 활성에 미치는 영향을 9일간 배양하여 그 변화를 측정하였다. 결과, 농도 1, 2, 4, 8% 처리시 112, 150, 188%까지 ALP 활성을 증가시켰다. ENA-A 이온수는 다시 ALP 효소 염색법과 Alizarin Red 염색으로 조골세포의 ALP활성유도, 분화와 석회화 형성능을 재확인하였으며 골기질 유전자의 발현의 변화도 확인하였다. 이에 본 연구결과를 통해 각종 무기질 성분을 함유한 ENA 이온수가 조골세포의 분화시에 hydroxyapatite 형성에 영향을 줌으로써 골다공증 예방에 효과가 있을것으로 생각하여 이를 보고하는 바이다.