• Journal of Periodontal and Implant Science
• /
• v.29 no.2
• /
• pp.277-289
• /
• 1999

The ultimate aim of periodontal treatment is periodontal regeneration, which necessiates the regeneration of bone tissues. To evaluate the effects of Dex growth and differentiation of MC3T3-E1 cells, cells were seeded in alpha-modified eagle medium containing 10% fetal bovine serum, 10mM beta-glycerophosphate , $50{\mu}g/ml$ of ascorbic acid, with or without $10^{-7}M$ Dex and examined cell proliferation activities, alkaline phosphatase activities, and bone nodule formation until 25days. The results were as follows : 1. In Dex group, cell proliferation activities were lower until 15 days compared to control group. Bone nodules formation were showed at 10 days. 2. In the time-response effect, ALP activities were increased until the 10 days in control groups thereafter decreased and ALP activities of Dex group were lower aspect than control group until the 10 days In this study, bone nodule formation of osteoblast-like cells were accelerated by Dex and cell proliferation activities, ALP activity of Dex group showed lower than control group. Dex was considered that it did suppress initial growth, but accerelate mineralization of osteoblast-like cells.

• BMB Reports
• /
• v.52 no.7
• /
• pp.469-474
• /
• 2019

Kruppel-like factor 2 (KLF2) has been implicated in the regulation of cell proliferation, differentiation, and survival in a variety of cells. Recently, it has been reported that KLF2 regulates the p65-mediated transactivation of $NF-{\kappa}B$. Although the $NF-{\kappa}B$ pathway plays an important role in the differentiation of osteoclasts and osteoblasts, the role of KLF2 in these bone cells has not yet been fully elucidated. In this study, we demonstrated that KLF2 regulates osteoclast and osteoblast differentiation. The overexpression of KLF2 in osteoclast precursor cells inhibited osteoclast differentiation by downregulating c-Fos, NFATc1, and TRAP expression, while KLF2 overexpression in osteoblasts enhanced osteoblast differentiation and function by upregulating Runx2, ALP, and BSP expression. Conversely, the downregulation of KLF2 with KLF2-specific siRNA increased osteoclast differentiation and inhibited osteoblast differentiation. Moreover, the overexpression of interferon regulatory protein 2-binding protein 2 (IRF2BP2), a regulator of KLF2, suppressed osteoclast differentiation and enhanced osteoblast differentiation and function. These effects were reversed by downregulating KLF2. Collectively, our data provide new insights and evidence to suggest that the IRF2BP2/KLF2 axis mediates osteoclast and osteoblast differentiation, thereby affecting bone homeostasis.

• Journal of Acupuncture Research
• /
• v.24 no.5
• /
• pp.13-22
• /
• 2007

Objectives : The differentiation of osteoblasts is controlled by various growth factors and matrix protein expressed in bone. The aim of this study was to investigate the effects of many herbs medicine(KHBJs) for bone healing that induces osteogenic activity in human osteoblast-like SaOS-2 cells. Methods : The osteogenic effects of KHBJs were evaluated by using cell proliferation(WST-8) assay, alkaline phosphatase(ALP) activity assay, colorimetric analysis of vascular endothelial growth factor(VEGF) expression in human osteoblast like SaOS-2 cell. Also, osteogenic activity of KHBJ fractions(KHBJB and KHBJR) by activity guided fractionation were evaluated. Results : About 7 KHBJs had effect on the proliferation of osteoblast like SaOS-2 cells, and dose-dependently increased alkaline phosphatase(ALP) activity. KHBJs markedly increased expression for VEGF. Fractionated KHBJs(KHBJB or KHBJR) not enhanced more than KHBJs on osteogenic activity in SaOS-2 cells. Conclusions: This study found that 7 KHBJs had effect on proliferation, ALP activity, and VEGF expression in osteoblast like SaOS-2 cells. These results propose that KHBJs can play an important role in osteoblastic bone formation, and may possibly lead to the development of bone-forming drugs.

• Molecules and Cells
• /
• v.39 no.7
• /
• pp.530-535
• /
• 2016

Large conductance calcium-activated potassium (BK) channels participate in many important physiological functions in excitable tissues such as neurons, cardiac and smooth muscles, whereas the knowledge of BK channels in bone tissues and osteoblasts remains elusive. To investigate the role of BK channels in osteoblasts, we used transcription activator-like effector nuclease (TALEN) to establish a BK knockout cell line on rat ROS17/2.8 osteoblast, and detected the proliferation and mineralization of the BK-knockout cells. Our study found that the BKknockout cells significantly decreased the ability of proliferation and mineralization as osteoblasts, compared to the wild type cells. The overall expression of osteoblast differentiation marker genes in the BK-knockout cells was significantly lower than that in wild type osteoblast cells. The BK-knockout osteoblast cell line in our study displays a phenotype decrease in osteoblast function which can mimic the pathological state of osteoblast and thus provide a working cell line as a tool for study of osteoblast function and bone related diseases.

• Proceedings of the Korean Society of Applied Pharmacology
• /
• 1998.11a
• /
• pp.145-145
• /
• 1998

In the present study, we have demonstrated that taurine could stimulate the production of nitric oxide and the activity of ERK2 (extracellular signal regulated protein kinase or pp42 MAP kinase). Nitric oxide(NO), the product of inducible nitric oxide synthase(iNOS), is known to be implicated in the metabolism of bone. ERK cascade plays a key role in the gene expression of iNOS in osteoblastic cell. We investigated whether taurine (l-20mM) could stimulate ERK2 activity, nitric oxide production, and inducible nitric oxide synthase in osteoblast-like UMR-106 cells. Nitric oxide was measured spectophotometrically as nitrite and the activation of ERK2 and iNOS was studied using Western 145 blot analysis. Taurine increased the production of nitric oxide in a dose-dependent manner and the effect was reached to a maximum at 10 mM. The activation of iNOS were consistent with NO levels. The tyrosine phosphorylation of ERK2 was increased by taurine in a time-dependent manner. The these result suggest that taurine might stimulate the production of nitric oxide in osteoblast-like cells by the activation of ERK2 and could regulate the metabolism of bone via nitric oxide.

• Korean Journal of Plant Resources
• /
• v.27 no.6
• /
• pp.593-600
• /
• 2014

Osteoporosis is a progressive bone disease characterized by low bone mass which is caused by disturbance in the balance between the activities of osteoblasts and osteoclasts. Postmenopausal osteoporosis is one of the most common disorders in women after menopause, which is linked to an estrogen deficiency and characterized by an excessive loss of trabecular bone. Rubus coreanus has been used for their various pharmacological properties in Asia as a traditional medicine. To investigate the effect of unripe fruits of R. coreanus 30% ethanol extract (RCE) on osteoblast-like cells (MG63) differentiation, we examined the effects of RCE on in vitro osteoblastic differentiation markers, alkaline phosphatase (ALP) activity and receptor activator of nuclear factor ${\kappa}$-B ligand (RANKL) and osteoprotegerin (OPG) expression. The high concentration (50 and $100{\mu}g/mL$) of RCE markedly increased ALP activity, whereas decreased the RANKL/OPG. We also investigated the effect of RCE on M-CSF plus RANKL-induced differentiation of pre-osteoclast cells (RAW 264.7). RCE treatment remarkably inhibited M-CSF/RANKL-induced formation of osteoclast-like multinuclear cells from RAW 264.7 cells. Moreover, the inhibitory effect of RCE was reduced by selective estrogen receptor-${\alpha}$ antagonist. Our research suggests that suggested that unripe fruits of R. coreanus may act beneficial effects on bone mass by regulating both osteoblast and osteoclast.

• The korean journal of orthodontics
• /
• v.24 no.1 s.44
• /
• pp.17-35
• /
• 1994

Vanadium is an essential trace element but has not been identified with a specific biogical role. To study the direct effects of vanadium on osteoblast, we incubated murin osteoblast-like (MC3T3-El) cells with various corcentration of vanadium oxide & sodium orthovanadate. This study was designed to investigate the effect of vanadium on DNA synthesis, alkaline phosphatase (ALP) activity, cAMP formation responsive to parathormone(PTH) and type I $\alpha$ 2 collagen ribonucleic acid (mRNA) level in murin osteoblast-like (MC3T3-El) cells. The cells were cultured in $\alpha-minimal$ essential medium$(\alpha-MEM)$ supplemented with $10\%$ fetal bovine serum (FBS) and then changed to $0.1\%$ FBS with various concenoation of vanadium oxide & sodium orthovanadate. Quiescent cultured MC3T3-El cells incubated for 24 hours with 2,5,10,15,20 ${\mu}M$ vanadium oxide incorporated $[^3H]Thymidine;$ every concentration showed increases in $[^3H]Thymidine$ incorporations dose dependant manner, the greatest response occurred at $20{\mu}M$. Quiescent cultured MC3T3-E1 cells incubated for 3days with 2,5,10,15,20 ${\mu}M$ vanadium oxide, for 2days with sodium orthovanadate and alkaline phosphatase was assayed with disodium phenyl phosphate as substrate. Vanadium oxide increased the alkaline phosphatase content in MC3T3-El cells at $2{\mu}M\;&\;6{\mu}M$ ; the greatest response occurred at $2{\mu}M$. But decreased at other content sodium orthovanadate increased alkaline phosphatase content in MC3T3-El cells at all concenoation ; the greatest response occurred at $4{\mu}M$. Quiescent cultured MC3T3-El cells incubated for 3days with $5,10{\mu}M$ vanadium oxide , with $5,8{\mu}M$ sodium orthovanadate and cAMP formation was measured by Radioimmunoassay(RIA). Vanadium oxide & sodium orthovanadate showed the tendency of inhibitory effects on cAMP responsiveness to PTH in MC3T3-El cells. Quiescent cultured MC3T3-El cells incubated for 24hours with $10,20{\mu}M$ vanadium oxide, with $5,10{\mu}M$ sodium orthovanadate and Type I $\alpha$ 2 collagen ribonucleic acid (mRNA) expression was studied by Nothern blot analysis. Northern blot analysis of vanadium oxide treated cells showed decreasing effects 0& sodium orthovanadate revealed increasing effects in type I $\alpha$ 2 collagen ribonucleic acid (mRNA) level.

• The Journal of Advanced Prosthodontics
• /
• v.5 no.4
• /
• pp.416-422
• /
• 2013

PURPOSE. This study was performed to define attachment and growth behavior of osteoblast-like cells and evaluate the gene expression on zirconia compared to titanium. MATERIALS AND METHODS. MC3T3-E1 cells were cultured on (1) titanium and (2) zirconia discs. The tetrazolium-based colorimetric assay (MTT test) was used for examining the attachment of cells. Cellular morphology was examined by scanning electron microscopy (SEM) and alkaline phosphatase (ALP) activity was measured to evaluate the cell differentiation rate. Mann-Whitney test was used to assess the significance level of the differences between the experimental groups. cDNA microarray was used for comparing the 20215 gene expressions on titanium and zirconia. RESULTS. From the MTT assay, there was no significant difference between titanium and zirconia (P>.05). From the SEM image, after 4 hours of culture, cells on both discs were triangular or elongated in shape with formation of filopodia. After 24 hours of culture, cells on both discs were more flattened and well spread compared to 4 hours of culture. From the ALP activity assay, the optical density of E1 cells on titanium was slightly higher than that of E1 cells on zirconia but there was no significant difference (P>.05). Most of the genes related to cell adhesion showed similar expression level between titanium and zirconia. CONCLUSION. Zirconia showed comparable biological responses of osteoblast-like cells to titanium for a short time during cell culture period. Most of the genes related to cell adhesion and signal showed similar expression level between titanium and zirconia.

• Journal of Periodontal and Implant Science
• /
• v.42 no.4
• /
• pp.113-118
• /
• 2012

Purpose: The aim of this study was to investigate the effects of synthetic fibronectin (FN) fragments, including fibrin binding sites from amino-terminal FN fragments containing type I repeats 1 to 5, on osteoblast-like cell activity. Methods: Oligopeptides ranging from 9 to 20 amino acids, designated FF1, FF3, and FF5, were synthesized by a solid-phase peptide synthesizing system, and we investigated the effects of these peptides on cell attachment and extent of mineralization using confocal microscopy, 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assays, and Alizarin red S staining. Results: FF3 and FF5 peptides increased the number of attached human osteoblastic cells, and FF3 administration led to prominent cell spreading. Mineralization was increased in FF3 and FF5 compared to FF1 and the untreated control. Conclusions: Taken together, it can be concluded that the fibrin-binding oligopeptides FF3 and FF5 enhanced cell attachment and mineralization on osteoblast-like cells. These results indicate that FF3 and FF5 have the potential to increase osteoblast-like cell activity. Performing an in vivo study may provide further possibilities for surface modification of biomimetic peptides to enhance osteogenesis, thus improving the regeneration of destroyed alveolar bone.

• Food Science and Biotechnology
• /
• v.17 no.6
• /
• pp.1214-1220
• /
• 2008

Secondary metabolites from the fruit body of Phellinus linteus were evaluated for their proliferative effect on human osteoblast-like cells. 3-[4,5-Dimethylthiazole-2-y1]-2,5-diphenyl-tetraxolium bromide (MTT) assay and alkaline phosphatase (ALP) activity assay were used to assess the effect those isolates on the human osteoblast-like cell line (Saos-2). Activity-guided fractionation led to the isolation of ALP-activating phenolic compounds through the extraction of P. linteus, solvent partitioning, and repeated silica gel and octadecyl silica gel (ODS) column chromatographic separations. From the result of spectroscopic data including nuclear magnetic resonance (NMR), mass spectrometry (MS), and infrared spectroscopy (IR), the chemical structures of the compounds were determined as 4-(4-hydroxyphenyl)-3-buten-2-one(1), 2-(3',4'-dihydroxyphenyl)-1,3-benzodioxole-5-aldehyde (2), 4-(3,4-dihydroxyphenyl)-3-buten-2-one (3), 3,4-dihydroxybenzaldehyde (4), and protocatechuic acid methyl ester (5), respectively. This study reports the first isolation of compounds 1-3 and 5 from P. linteus. In addition, all phenolic compounds stimulated proliferation of the osteoblast-like cells and increased their ALP activity in a dose-dependent manner ($10^{-8}$ to $10^{-1}\;mg/mL$). The present data demonstrate that phenolic compounds in P. linteus stimulated mineralization in bone formation caused by osteoporosis. The bone-formation effect of P. linteus seems to be mediated, at least partly, by the stimulating effect of the phenolic compounds on the growth of osteoblasts.