• Transactions of the Korean Society of Mechanical Engineers A
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• v.33 no.7
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• pp.629-636
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• 2009

Mechanical stimulation is known to play a vital role on the differentiation of mesenchymal stem cells (MSCs) to pre-osteoblasts. In this research, we developed a tensile cell stimulator, composed of a DC motor-driven actuator and LVDT sensor for measuring linear displacement, to study the effects of tensile stress on osteogenic differentiation of MSCs. First, we demonstrated the reliability of this device by showing the uniform strain field in the silicon substrate. Secondly, we investigated the effects of tensile stretching on osteogenic differentiation. We imposed a pre-set cyclic strain at a fixed frequency on cell monolayer cultured on a flexible silicon substrate while varying its amplitude and duration. 60 min of resting period was allowed between 30 min of cyclic stretching and this cycle is repeated up to 7 days. Under the combined stimulation with osteogenic media and mechanical stretching, the osteogenic markers such as alkaline phosphatase (ALP), osterix, and osteopontin began to get expressed as early as 4 days of stimulation, which is much shorter than what is typically required for osteogenic media induced differentiation. Moreover, different markers were induced at different magnitudes of the applied strains. Lastly, for the case of ALP, we observed the antagonistic effects of osteogenic media when combined with mechanical stretching.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.30 no.2
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• pp.133-141
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• 2008

Stem cells have self-renewal capacity, long-term viability, and multiline age potential. Adult bone marrow contains mesenchymal stem cells. Bone marrow-derived mesenchymal stem cells (BMSCs) are progenitors of skeletal tissue components and can differentiate into adipocytes, chondrocytes, osteoblasts, and myoblasts in vitro and undergo differentiation in vivo. However, the clinical use of BMSCs has presented problems, including pain, morbidity, and low cell number upon harvest. Recent studies have identified a putative stem cell population within the adipose tissue. Human adipose tissue contains pluripotent stem cells simillar to bone marrow-derived stem cells that can differentiate toward the osteogenic, adipogenic, myogenic, and chondrogenic lineages. Human adipose tissue-derived stem cells (ATSCs) could be proposed as an alternative source of adult bone marrow stem cells, and could be obtained in large quantities, under local anesthesia, with minimal discomfort. Human adipose tissue obtained by liposuction was processed to obtain ATSCs. In this study, we compared the osteogenic differentiation of ATSCs in a specific osteogenic induction medium with that in a non-osteogenic medium. ATSCs were incubated in an osteogenic medium for 28 days to induce osteogenesis respectively. Osteogenic differentiation was assessed by von Kossa and alkaline phosphatase staining. Expression of osteocyte specific bone sialoprotein, osteocalcin, collagen type I and alkaline phosphatase, bone morphogenic protein 2, bone morphogenic protein 6 was confirmed by RT-PCR. ATSCs incubated in the osteogenic medium were stained positively for von Kossa and alkaline phosphatase staining. Expression of osteocyte specific genes was also detected. Since this cell population can be easily identified through fluorescence microscopy, it may be an ideal source of ATSCs for further experiments on stem cell biology and tissue engineering. The present results show that ADSCs have an ability to differentiate into osteoblasts. In the present study, we extend this approach to characterize adipose tissue-derived stem cells.

• International Journal of Oral Biology
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• v.33 no.3
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• pp.91-95
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• 2008

Embryonic stem cells have a pluripotency and a potential to differentiate to all type of cells. In our previous study, we have shown that embryonic stem cells (ESCs) lines can be generated from murine parthenogenetic embryos. This parthenogenetic ESCs line can be a useful stem cell source for tissue repair and regeneration. The defect in full-term development of parthenogenetic ESCs line enables researchers to avoid the ethical concerns related with ESCs research. In this study, we presented the results demonstrating that parthenogenetic ESCs can be induced into osteogenic cells by supplementing culture media with ascorbic acid and $\beta$-glycerophosphate. These cells showed morphologies of osteogenic cells and it was proven by Von Kossa staining and Alizarin Red staining. Expression of marker genes for osteogenic cells (osteopontin, osteonectin, alkaline phosphatase, osteocalcin, bone-sialoprotein, collagen type1, and Cbfa1) also confirmed osteogenic potential of these cells. These results demonstrate that osteogenic cells can be generated from parthenogenetic ESCs in vitro.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.9
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• pp.5379-5383
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• 2013

Therapeutic effects of zoledronic acid (ZOL) on giant cell tumour of bone (GCT) have been proven. Apoptosis induction was considered to be one of the mechanisms of ZOL tumour inhibition. In this study, we presented the possibility of an osteogenic differentiation stimulation mechanism of ZOL and further investigated dosage and time effects. We treated stromal cells of GCT (GCTSC) with ZOL for 48 hours at different concentrations ($0{\mu}M$, $0.01{\mu}M$, $0.1{\mu}M$, $1{\mu}M$, 5${\mu}M$, $30{\mu}M$) and assessed apoptotic and osteogenic differentiation markers with immunohistochemical techniques and real-time quantitative RT-PCR. Our results suggested that ZOL enhanced mRNA expression of Cbfa-1, osterix and osteocalcin genes with a maximum effect at $1{\mu}M$ in GCTSC. Time course experiments indicated a time dependent osteogenic differentiation effect. In conclusion, ZOL may be considered as an adjuvant in the treatment of GCT not only by inducing apoptosis but also by stimulating osteogenic differentiation of remaining tumor stromal cells after surgery.

• Journal of Microbiology and Biotechnology
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• v.30 no.3
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• pp.448-458
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• 2020

We investigated the therapeutic effects of microRNA-139-5p in relation to osteoporosis of bone marrow-derived mesenchymal stem cell (BMSCs) and its underlying mechanisms. In this study we used a dexamethasone-induced in vivo model of osteoporosis and BMSCs were used for the in vitro model. Real-time quantitative polymerase chain reaction (RT-PCR) and gene chip were used to analyze the expression of microRNA-139-5p. In an osteoporosis rat model, the expression of microRNA-139-5p was increased, compared with normal group. Down-regulation of microRNA-139-5p promotes cell proliferation and osteogenic differentiation in BMSCs. Especially, up-regulation of microRNA-139-5p reduced cell proliferation and osteogenic differentiation in BMSCs. Overexpression of miR-139-5p induced Wnt/β-catenin and down-regulated NOTCH1 signaling in BMSCs. Down-regulation of miR-139-5p suppressed Wnt/β-catenin and induced NOTCH1 signaling in BMSCs. The inhibition of NOTCH1 reduced the effects of anti-miR-139-5p on cell proliferation and osteogenic differentiation in BMSCs. Activation of Wnt/β-catenin also inhibited the effects of anti-miR-139-5p on cell proliferation and osteogenic differentiation in BMSCs. Taken together, our results suggested that the inhibition of microRNA-139-5p promotes osteogenic differentiation of BMSCs via targeting Wnt/β-catenin signaling pathway by NOTCH1.

• BMB Reports
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• v.53 no.12
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• pp.646-651
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• 2020

Bone resorption is linked to bone formation via temporal and spatial coupling within the remodeling cycle. Several lines of evidence point to the critical role of coupling factors derived from pre-osteoclasts (POCs) during the regulation of bone marrow-derived mesenchymal stem cells (BMMSCs). However, the role of glial cell-derived neurotrophic factor (GDNF) in BMMSCs is not completely understood. Herein, we demonstrate the role of POC-derived GDNF in regulating the migration and osteogenic differentiation of BMMSCs. RNA sequencing revealed GDNF upregulation in POCs compared with monocytes/macrophages. Specifically, BMMSC migration was inhibited by a neutralizing antibody against GDNF in pre-osteoclast-conditioned medium (POC-CM), whereas treatment with a recombinant GDNF enhanced migration and osteogenic differentiation. In addition, POC-CM derived from GDNF knock-downed bone marrow macrophages suppressed BMMSC migration and osteogenic differentiation. SPP86, a small molecule inhibitor, inhibits BMMSC migration and osteogenic differentiation by targeting the receptor tyrosine kinase RET, which is recruited by GDNF into the GFRα1 complex. Overall, this study highlights the role of POC-derived GDNF in BMMSC migration and osteogenic differentiation, suggesting that GDNF regulates bone metabolism.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.35 no.4
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• pp.205-212
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• 2009

Purpose : The purpose of this study was to examine the expression of various angiogenic factors during osteoblastic differentiation of periostealderived cells and the effects of osteogenic inductive medium of periosteal-derived cells on the proliferation of endothelial progenitor cells. Materials and methods : Periosteal-derived cells were obtained from mandibular periosteums and introduced into the cell culture. After passage 3, the cells were divided into two groups and cultured for 21 days. In one group, the cells were cultured in the DMEM supplemented with osteogenic inductive agent, including 50g/ml L-ascorbic acid 2-phosphate, 10 nM dexamethasone and 10 mM -glycerophosphate. In the other group, they were cultured in DMEM supplemented without osteogenic inductive agent. VEGF isoforms, VEGFR-1, VEGFR-2, and neuropilin-1 mRNA expression was observed. Human umbilical cord blood-derived endothelial progenitor cell proliferation was also observed. Results : The expression of VEGF isoforms was higher in osteogenic inductive medium than in non-osteogenic inductive medium. The expression of VEGFR-2 was also higher in osteogenic inductive medium than in non-osteogenic inductive medium. However, the expression of VEGFR-1 and neuropilin-1 was similar in both osteogenic inductive medium and non-osteogenic inductive medium. In addition, conditioned medium from differentiated periosteal-derived cells stimulated human umbilical cord blood-derived endothelial progenitor cell numbers compared to conditioned medium from non-differentiated periosteal-derived cells. Conclusion : These results suggest that in vitro osteoblastic differentiation of periosteal-derived cells has angiogenic capacity to support endothelial progenitor cell numbers.

• Journal of Periodontal and Implant Science
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• v.53 no.1
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• pp.54-68
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• 2023

Purpose: The purpose of this study was to determine whether metformin (MF) could alleviate the expresssion of reactive oxygen species (ROS) and improve the osteogenic ability of bone marrow mesenchymal stem cells derived from diabetic rats (drBMSCs) in vitro, and to evaluate the effect of MF on the ectopic osteogenesis of drBMSCs in a nude mouse model in vivo. Methods: BMSCs were extracted from normal and diabetic rats. In vitro, a cell viability assay (Cell Counting Kit-8), tests of alkaline phosphatase (ALP) activity, and western blot analysis were first used to determine the cell proliferation and osteogenic differentiation of drBMSCs that were subjected to treatment with different concentrations of MF (0, 50, 100, 200, 500 µM). The cells were then divided into 5 groups: (1) normal rat BMSCs (the BMSCs derived from normal rats group), (2) the drBMSCs group, (3) the drBMSCs + Mito-TEMPO (10 µM, ROS scavenger) group, (4) the drBMSCs + MF (200 µM) group, and (5) the drBMSCs + MF (200 µM) + H₂O₂ (50 µM, ROS activator) group. Intracellular ROS detection, a senescence-associated β-galactosidase assay, ALP staining, alizarin red staining, western blotting, and immunofluorescence assays were performed to determine the effects of MF on oxidative stress and osteogenic differentiation in drBMSCs. In vivo, the effect of MF on the ectopic osteogenesis of drBMSCs was evaluated in a nude mouse model. Results: MF effectively reduced ROS levels in drBMSCs. The cell proliferation, ALP activity, mineral deposition, and osteogenic-related protein expression of drBMSCs were demonstrably higher in the MF-treated group than in the non-MF-treated group. H₂O₂ inhibited the effects of MF. In addition, ectopic osteogenesis was significantly increased in drBMSCs treated with MF. Conclusions: MF promoted the proliferation and osteogenic differentiation of drBMSCs by inhibiting the oxidative stress induced by diabetes and enhenced the ectopic bone formation of drBMSCs in nude mice.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.32 no.4
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• pp.327-333
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• 2006

Future cell-based therapies such as tissue engineering will benefit from a source of autogenous pluripotent stem cells. There are embryonic stem cells (ESC) and autologous adult stem cells, two general types of stem cells potentilally useful for these applications. But practical use of ESC is limited due to potential problems of cell regulation and ethical considerations. To get bone marrow stem cells is relatively burden to patients because of pain, anesthesia requirement. The ideal stem cells are required of such as the following advantages: easy to obtain, minimal patient discomfort and a capability of yielding enough cell numbers. Adipose autologus tissue taken from intraoral fatty pad or abdomen may represent such a source. Our study designed to demonstrate the ability of human adipose tissue-derived stromal cells (hATSC) from human abdominal adipose tissue diffentiating into osteocyte and adipocyte under culture in vitro conditions. As a result of experiment, we identified stromal cell derived adipose tissue has the multilineage potentiality under appropriate culture conditions. And the adipose stromal cells expressed several mesenchymal stem cell related antigen (CD29, CD44) reactions. Secondary, we compared the culture results of a group of hATSC stimulated with TGF-${\beta}$1, bFGF with a hATSC group without growth factors to confirm whether cytokines have a important role of the proliferation in osteogenic differentiation. The role of cytokines such as TGF-${\beta}$1, bFGF increased hATSC's osteogenic differentiation especially when TGF-${\beta}$1 and bFGF were used together. These results suggest that adipose stromal cells with growth factors could be efficiently available for cell-based bone regeneration.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.36 no.3
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• pp.172-176
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• 2010

Postirradiation extraosseous osteogenic sarcomas are uncommon in the head and neck, despite the extensive use of high-dose radiation. It has been described as de novo radiation-induced neoplasm. We present a 73-year-old male who had been treated by radiotherapy for gingival cancer 7 years earlier and later developed extraosseous osteogenic sarcomas (EOSs) of the neck. Microscopically, the neck mass was composed with mesenchymal malignant cells with cartilaginous and osteogenic differentiation. Immunohistochemical stain demonstrated strong positivity of tumor cells for Snail, the one of major epithelial-mesenchymal transition (EMT) inducer. The E-cadherin expression was scarce, showing inverse relationship to Snail expression. Compared with previous squamous cell carcinoma (SCC) of the gingiva, the present EOS sample revealed the remained epithelial cells on cytokeratin immunohistochemistry, suggesting the tumor arise from the cells of epithelial origin. We have also reviewed the previous 6 cases of head and neck EOSs carefully. The clinicopathologic features of the unusual lesion suggest that it is an incomplete EMT of precedent epithelial malignancy rather than de novo pathology.