• BMB Reports
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• v.47 no.8
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• pp.463-468
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• 2014

Osteoblasts are specialized mesenchymal cells that are responsible for bone formation. In this study, we examine the role of GATA4 in osteoblast differentiation. GATA4 was abundantly expressed in preosteoblast cells and gradually down-regulated during osteoblast differentiation. Overexpression of GATA4 in osteoblastic cells inhibited alkaline phosphatase activity and nodule formation in osteogenic conditioned cell culture system. In addition, overexpression of GATA4 attenuated expression of osteogenic marker genes, including Runx2, alkaline phosphatase, bone sialoprotein, and osteocalcin, all of which are important for osteoblast differentiation and function. Overexpression of GATA4 attenuated Runx2 promoter activity, whereas silencing of GATA4 increased Runx2 induction. We found that GATA4 interacted with Dlx5 and subsequently decreased Dlx5 binding activity to Runx2 promoter region. Our data suggest that GATA4 acts as a negative regulator in osteoblast differentiation by downregulation of Runx2.

• Korean Journal of Medicinal Crop Science
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• v.19 no.6
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• pp.491-500
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• 2011

Ursolic acid, triterpenoid compound has been shown to stimulate osteoblast differentiation and enhance bone formation. In the present study, we examined the effects of similar triterpenoid compounds, oleanolic acid (OA) and its derivatives, such as oleanolic acid acetate (OAA) and oleanolic acetate methyl ester (OAM) on the bone formation in MC3T3-E1 osteoblast cells. We determined cellular proliferation, alkaline phosphatase (ALP) activity, mineralization, and expression of osteoblast specific genes and mitogen activated protein kinase phosphorylation. Treatment of $0.1-10{\mu}m$ OA, OAA, and OAM increased cellular proliferation, but not significantly increased as compared with dimethyl sulfoxide (DMSO). OA, OAA, and OAM at 5uM concentration enhanced ALP expression, mineralization, and osteocalcin (OCN) mRNA level. In conclusion, OA and its derivatives stimulated the osteoblast differentiation by increasing ALP, mineralization, and OCN mRNA expression. However, there were no significantly difference on osteoblast differentiation among treatment of OA, OAA, and OAM.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.30 no.4
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• pp.323-330
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• 2004

Estrogen may promote osteoblast/osteocyte viability by limiting apoptotic cell death. We hypothesize that hsp27 is an estrogen- regulated protein that can promote osteoblast viability by increasing osteoblast resistance to apoptosis. The purpose of this study was to determine the effect of estrogen treatment and heat shock on $TNF{\alpha}$ - induced apoptosis in the MC3T3-E1 cell line. Cells were treated with 0 - 100 nM $17{\beta}$ estradiol (or ICI 182780) for 0 - 24 hours before heat shock. After recovery, apoptosis was induced by treatment with 0 - 10 ng/ml TNF${\alpha}$. Hsp levels were evaluated by Northern and Western analysis using hsp27, hsp47, hsp70c and hsp70i - specific reagents. Apoptosis was revealed by in situ labeling with Terminal Deoxyribonucleotide Transferase (TUNEL). A 5 - fold increase in hsp27 protein and mRNA was noted after 5 hours of treatment with 10 - 20 nM $17{\beta}$ estradiol prior to heat shock. Increased abundance of hsp47, hsp70c or hsp70i was not observed. TUNEL indicated that estrogen treatment also reduced (50%) MC3T3-E1 cell susceptibility to $TNF{\alpha}$ - induced apoptosis. Treatment with hsp27-specific antisense oligonucleotides prevented hsp27 protein expression and abolished the protective effects of heat shock and estrogen treatment on $TNF{\alpha}$- induced apoptosis. Hsp27 is a determinant of osteoblast apoptosis, and estrogen treatment increases hsp27 levels in cultured osteoblastic cells. Hsp27 contributes to the control of osteoblast apoptosis and may be manipulated by estrogenic or alternative pathways for the improvement of bone mass.

• Journal of dental hygiene science
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• v.14 no.2
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• pp.101-106
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• 2014

In this study, we investigated the proliferative and adhesional effect of human osteoblast like MG-63 cell treated with low intensity pulsed ultrasound (LIPUS). We tested the effectiveness of LIPUS in human osteoblast like MG-63 cells. Cell proliferation was measured using a water soluble tetrazolium salts-1 assay. The mRNA expression of alkaline phosphate, vascular endothelial growth factor (VEGF), integrin alpha 2, colla 1A1 were performed by reverse transcription-polymerase chain reaction. LIPUS was no cytotoxicity in human osteoblast like MG-63 cells. In addition, the data show that treatment with 1 MHz and 3 MHz LIPUS on increased proliferation 7 days after. There were significant increased in mRNA expression of alkaline phosphatase, osteocalcin, VEGF, integrin alpha 2 and colla 1A1 (p<0.05). Therefore, the LIPUS significantly increased differential expression of mRNA levels in osteoblast like MG-63 cell and new possibilities in dental clinical practice.

• The Journal of Korean Academy of Prosthodontics
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• v.46 no.3
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• pp.227-237
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• 2008

STATEMENT OF PROBLEM: Zirconium oxide can be a substitute to titanium as implant materials to solve the esthetic problems of dark color in the gingival portion of implant restorations. PURPOSE: This study was performed to define attachment and growth behavior of osteoblast- like cells cultured on grooved surfaces of zirconium oxide and evaluate the genetic effect of zirconium oxide surfaces using the reverse transcriptase-polymerase chain reaction (RT-PCR). MATERIAL AND METHODS: MC3T3-E1 cells were cultured on (1) commercially pure titanium discs with smooth surface (T group), (2) yttrium-stabilized tetragonal zirconia polycrystal (Y-TZP) with machined surface (ZS group), and (3) Y-TZP with $100{\mu}m$ grooves (ZG group). Cell proliferation activity was evaluated through MTT assay and cell morphology was examined by SEM. The mRNA expression of Runx2, alkaline phosphatase, osteocalcin, TGF-${\beta}1$, IGF-1, G3PDH in E1 cells were evaluated by RT-PCR. RESULTS: From the MTT assay, after 48 hours of adhesion of MC3T3-E1 cells, the mean optical density value of T group and ZG group significantly increased compared to the ZS group. SEM images of osteoblast-like cells showed that significantly more cells were observed to attach to the grooves and appeared to follow the direction of the grooves. After 24 hours of cell adhesion, more spreading and flattening of cells with active filopodia formation occurred. Results of RT-PCR suggest that T group, ZS group, and ZG group showed comparable osteoblast-specific gene expression after 24 hours of cell incubation. CONCLUSION: Surface topography and material of implants can play an important role in expression of osteoblast phenotype markers. Zirconia ceramic showed comparable biological responses of osteoblast-like cells with titanium during a short-time cell culture period. Also, grooves influence cell spreading and guide the cells to be aligned within surface grooves.

• Journal of Periodontal and Implant Science
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• v.34 no.2
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• pp.425-448
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• 2004

A bioactive and degradable poly(epsilon -caprolactone)/silica nanohybrid(PSH) was synthesized for the application as a bone substitute. PSH was manufactured by using silica and polycaprolacton. PSH was manufactured in some composition after low crystaline apatite had been formed in simulated body fluid and, was used this study. The safety of the PSH was established by test of acute, and subacute toxicity, sensitization cytotoxicity and sterility. In order to assess activity of osteoblast, the test for attaching osteoblast, proliferation test for osteoblast, differentiating gene expression test are performed in vitro. And bone substitutes were grafted in rabbit's calvarium, during 8 weeks for testing efficacy of bone substitutes. Degree of osteogenesis and absorption of substitutes were evaluated in microscopic level. In result, it was not appeared that acute and subacute toxicity, sensitization in intradermal induction phase, topical induction phase and challenge phase. It was shown that the test can not inhibit cell proliferation. adversely, it had some ability to accelerate cell proliferation. The result of sterility test described bacterial growth was not detected in most test tube. The attaching and proliferation test of osteoblast had good results. In the result of differentiating gene expression test for osteoblast, cbfa1 and, alkaline phosphatase, osteocalcin and GAPDH were detected with mRNA analysis. In the PSH bone formation test, ostgeoblastic activity would be different as material constitution but it had good new bone formation ability except group #218. futhermore, some material had been absorbed within 8 weeks. Above studies, PSH had bio-compatibility with human body, new bone formation ability and accelerate osteoblastic activity. So it would be the efficient bone substitute material with bio-active and biodegradable.

• Journal of Dental Rehabilitation and Applied Science
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• v.19 no.4
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• pp.281-290
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• 2003

Platelet-rich plasma which is made with the newly developed technique concentrating platelets 3-folds or more is also proven to be very effective method to stimulate and accelerate the healing of bone and soft tissue. This study is aimed to investigate the effect of platelet-rich plasma on the attachment of osteoblast. To evaluate the effect on human, human osteoblast cell line was cultured. Platelet-rich plasma was extracted from the blood of a healthy volunteer. The effect on the attachment was evaluated by MTT assay. To evaluate autocrine and paracrine effect on osteoblast, conditioned medium was made and compared with platelet-rich plasma. By western blot analysis, the expression of fibronectin and vitronectin in experimental groups was examined. The results were as following: The cellular attachment of osteoblast cell line increased depending on the concentration of platelet-rich plasma and conditioned medium. The amount of increasing was similar between two groups. The expression of fibronectin and vitronectin in platelet-rich plasma and conditioned medium is more than control group in western blot analysis. These findings imply that platelet-rich plasma enhance the cellular attachment by inducing fibronectin, vitronectin from osteoblast and maximize the cellular attachment by using the autocrine and paracrine effect of platelet-rich plasma.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.36 no.4
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• pp.243-249
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• 2010

Tissue engineered bone (TEB) can replace an autogenous bone graft requiring an secondary operation site as well as avoid complications like inflammation or infection from xenogenic or synthetic bone graft. Adult mesenchymal stem cells (MSC) for TEB are considered to have various ranges of differentiation capacity or multipotency by the donor site and age. This study examined the effect of age on proliferation capacity, differentiation capacity and bone morphogenetic protein-2 (BMP-2) responsiveness of human bone marrow stromal cells (hBMSC) according to the age. In addition, to evaluate the effect on enhancement for osteoblast differentiation, the hBMSC were treated with Trichostatin A (TSA) and 5-Azacitidine (5-AZC) which was HDAC inhibitors and methyltransferase inhibitors respectively affecting chromatin remodeling temporarily and reversibly. The young and old group of hBMSC obtained from the iliac crest from total 9 healthy patients, showed similar proliferation capacity. Cell surface markers such as CD34, CD45, CD90 and CD105 showed uniform expression regardless of age. However, the young group showed more prominent transdifferentiation capacity with adipogenic differentiation. The osteoblast differentiation capacity or BMP responsiveness was low and similar between young and old group. TSA and 5-AZC showed potential for enhancing the BMP effect on osteoblast differentiation by increasing the expression level of osteogenic master gene, such as DLX5, ALP. More study will be needed to determine the positive effect of the reversible function of HDAC inhibitors or methyltransferase inhibitors on enhancing the low osteoblast differentiation capacity of hBMSC.

• Journal of Periodontal and Implant Science
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• v.33 no.2
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• pp.225-246
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• 2003

Recent study on the enamel matrix derivatives explained on the effects of new bone and new attachment formation in infrabony pocket of periodontal defects. The purpose of this study was to investigate on the biological effects of enamel matrix derivatives to attachment, proliferation and activation of periodontal ligament and osteoblast cells, After treatment of osteoblast and PDL cells with various Emdogain concentration level(0.03${\mu}g$/ml, 3${\mu}g$/ml, 300${\mu}g$/ml), activation of osteogenetic factor, calcified nodule formation and measuring alkaline phosphatase activity(ALP) were performed. 1. Both osteoblast and PDL cell showed increasing initial cell attachment with 300${\mu}g$/ml Emdogain concentration. 2. At the level of 300${\mu}g$/ml, accelerated proliferation of oseoblast and PDL cell was appeared. 3. As Emdogain's concentration increased, increased ALP activation of osteoblast was shown. In case of PDL cell, Emdogain increased ALP activation prominently at the level of 300${\mu}g$/ml. 4. No statistically significant activating change were founded at all of the concentrations of Emdogain on the activating of transcript factor Runx2 for differentiating osteoblast. 5. At the level of 300${\mu}g$/ml, calcified nodule formation was increased prominently to compare with other concentration. These results indicated that Emdogain should activate initial attachment, proliferation and activation, but not on Runx2 activation and can be used for useful tool of the treatment of periodontal tissue regeneration.

• Journal of The Korean Dental Society of Anesthesiology
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• v.14 no.2
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• pp.107-114
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• 2014

Background: Angiogenesis has been recognized an essential precondition for osteogenesis. Because reduction and disruption of the blood supply to tissue cause tissue hypoxia, pathological bone loss affected by hypoxia often can occur in various clinical conditions. The effects of propofol on the process of osteogenesis have received little direct attention. Therefore, we investigated the effect of propofol on the growth and function of osteoblasts under hypoxic condition. Methods: After propofol (3, 30, $300{\mu}M$) preconditioning for 2 hours, hFOB 1.19 human osteoblast cells were cultured under 1 % oxygen tension for 48 hours. Using real time PCR and western blot analysis, we analyzed the expression of, BMP-2, TGF-${\beta}1$, type I collagen, osteocalcin, HIF-1s and Akt. Cell viability was also determined by MTT assay. Results: Propofol preconditioning on hypoxic-cultured osteoblast promoted the expressions of BMP-2, TGF-${\beta}1$, type I collagen and osteocalcin and induced hypoxia-mediated HIF-1 activation and the expression of Akt protein. Propofol with $300{\mu}M$ significant decreased cell viability compared to control. Conclusions: Clinically relevant concentrations of propofol are not cytotoxic to hypoxic osteoblasts in vitro. Propofol preconditioning on hypoxic-cultured osteoblast stimulates proliferation and differentiation of osteoblast through induced expression of BMP-2, TGF-${\beta}1$, type I collagen and osteocalcin. Propofol might promote angiogenesis and bone regeneration under hypoxic condition.