• Maxillofacial Plastic and Reconstructive Surgery
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• v.28 no.2
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• pp.111-117
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• 2006

An area of current research is investigating the app1ication of human mesenchymal stem cells or hMSCs as a cell-based regenerative therapy. In order to achieve effective bone regeneration, appropriate matrices functioning as cell-carriers must be identified and optimized in terms of function, efficacy and biocompatibility. Two methods of approaching optimization of matrices are to facilitate adhesion of the donor hMSCs and furthermore to facilitate recruitment of host progenitor cells to osteoblastic differentiation. Pleiotrophin is an extracellular matrix protein that was first identified in developing rat brains and believed to be associated with developing neuronal pathways. A recent publication by Imai and colleagues demonstrated that transgenic mice with upregulated pleiotrophin expression developed a greater volume of cortical as well as cancellous bone. The proposed mechanism of action of pleiotrophin is demonstrated here. Through either environmental stresses and/or intracellular regulation, there is an increase in pleiotrophin production. The pleiotrophin is released extracellularly into areas requiring bone deposition. A receptor-mediated process recruits host osteoprogenitor cells into these areas. Therefore, the aim of our study was to investigate the osteoconductive properties of pleiotrophin. We wanted to determine if pleiotrophin coating facilitates cellular adhesion and furthermore if this has any effect on hMSCs derived bone formation in an animal model. The results showed a dose dependent response of cellular adhesion in fibronectin samples, and cellular adhesion was facilitated with increasing pleiotrophin concentrations. Histologic findings taken after 5 weeks implantation in SCID mouse showed no presence of bone formation with only a dense fibrous connective tissue. Possible explanations for the results of the osteogenesis assay include inappropriate cell loading.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.34 no.6
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• pp.384-390
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• 2012

Purpose: The purpose of this study is to examine in vivo osteogenesis of cultured human periosteal-derived cells and polydioxanone/pluronic F127 scaffold. Methods: Two one-year-old miniature pigs were used in this study. $2{\times}10^6$ periosteal-derived cells in 1 mL medium were seeded by dropping the cell suspension into the polydioxanone/pluronic F127 scaffold. These cell-scaffold constructs were cultured in osteogenic Dulbecco's modified Eagle's medium for 7 days. Under general anesthesia with azaperone and tiletamine-zolazepam, the mandibular body and ramus of the pigs were exposed. Three bony defects were created. Polydioxanone/pluronic F127 scaffold with periosteal-derived cells and the scaffold only were implanted into each defect. Another defect was left empty. Twelve weeks after implantation, the animals were sacrificed. Results: New bone formation was clearly observed in the polydioxanone/pluronic F127 scaffold with periosteal-derived cells. Newly generated bone was also observed in the scaffold without periosteal-derived osteoblasts and empty defect, but was mostly limited to the periphery. Conclusion: These results suggest that cultured human periosteal-derived cells have good osteogenic capacity in a polydioxanone/pluronic F127 scaffold, which provides a proper environment for the osteoblastic differentiation of these cells.

• Journal of Life Science
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• v.33 no.11
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• pp.851-858
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• 2023

Unique cartilage matrix-associated protein (UCMA) is an extrahepatic vitamin K-dependent protein rich in γ-carboxylated (Gla) residues. UCMA has been recognized for its ability to promote osteoblast differentiation and enhance bone formation; however, its impact on osteoblasts under hyperglycemic stress remains unknown. In this paper, we investigated the effect of UCMA on MC3T3-E1 osteoblastic cells under hyperglycemic conditions. After exposure to high glucose, the MC3T3-E1 cells were treated with recombinant UCMA proteins. CellROX and MitoSOX staining showed that the production of reactive oxygen species (ROS), which initially increased under high-glucose conditions in MC3T3-E1 cells, decreased after UCMA treatment. Additionally, quantitative polymerase chain reaction revealed increased expression of antioxidant genes, nuclear factor erythroid 2-related factor 2 and superoxide dismutase 1, in the MC3T3-E1 cells exposed to both high glucose and UCMA. UCMA treatment downregulated the expression of heme oxygenase-1, which reduced its translocation from the cytosol to the nucleus. Moreover, the expression of dynamin-related protein 1, a mitochondrial fission marker, was upregulated, and AKT signaling was inhibited after UCMA treatment. Overall, UCMA appears to mitigate ROS production, increase antioxidant gene expression, impact mitochondrial dynamics, and modulate AKT signaling in osteoblasts exposed to high-glucose conditions. This study advances our understanding of the cellular mechanism of UCMA and suggests its potential use as a novel therapeutic agent for bone complications related to metabolic disorders.

• The Korean Journal of Pharmacology
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• v.26 no.2
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• pp.193-207
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• 1990

Transforming growth factor ${\beta}(TGF-{\beta})$ is a multifunctional polypeptide with diverse effects on the proliferation, differentiation and other functions in many cell types. $TGF-{\beta}$ is highly abundant in bone matrix and induces divergent responses in many aspects of bone cell metabolism . Several lines of investigation indicate that matrix-associated $TGF-{\beta}$ is the products of bone cells themselves. However, exact bone cell type reponsible for the production of $TGF-{\beta}$ is still in controversy, The present study was undertaken to determine the cellular origin of matrix-associated $TGF-{\beta}$ and to assess how different bone cells respond to $TGF-{\beta}$. As a prerequisite for this, 5 bone cell populations of distinct phenotype were isolated from fetal calvaria with sequential enzyme digestion protocol and biochemical characterization. Calvarial cell populations released in early stage showed fibroblastic features whereas populations relesed later was enriched with osteoblast-like cell as judged by their acid and alkaline phosphatase activities, cAMP responsiveness to parathyroid hormone, calcitonin and prostaglandin $E_2$ and collagen synthesis rate. By polyacylamide gel and immunoblot analysis of bone and calvarial cell extracts, presence of $TGF-{\beta}$ in bone tissues and production of $TGF-{\beta}$ by bone cells were confirmed again. Subsequent analysis of calvarial cell extracts prepared as individual population revealed that all calvarial cell populations synthesize $TGF-{\beta}$. Exogenously added $TGF-{\beta}$ induced biphasic response upon bone cell proliferation under serum-free condition. In osteoblastic cell populations, it was stimulatory whereas inhibitory in fibroblastic cell populations. In contrast, collagen and noncollagen protein synthesis of all calvarial cell populations were stimulated by $TGF-{\beta}$. Enhancement of protein synthesis was found to be more general rather than specific for collagen synthesis. In addition, effects of $TGF-{\beta}$ on protein synthesis were independent to its effects on cell proliferation. In summary, production of $TGF-{\beta}$ by bone cells and differential actions on various cell populations observed in this study suggest that $TGF-{\beta}$ may play an important role in the regulation of bone metabolism by modulating the specific cellular functions in autocrine and paracrine fashion.

• Journal of Periodontal and Implant Science
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• v.24 no.2
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• pp.219-237
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• 1994

The ultimate goal of clinical periodontal therapy is to achieve regeneration of a healthy connective tissue reattachment. Conventional therapy including scaling, root planing, gingival curettage, gingivectomy and flap procedures of various types results primarily in repair rather than regeneration of the periodontium. In order for periodontal regeneration to occur, progenitor periodontal ligament cells must migrate to the denuded root surface, attach to it, proliferate and mature into an organized and functional fibrous attachment apparatus. Polypeptide growth factors belong to a class of potent biologic mediators which regulate cell differentiation, proliferation, migration and metabolism. Insulin-like growth factor-I (IGF- I ) of these factors appear to have an important role in periodontal wound healing and bone formation. The purpose of this study is to evaluate the effects of IGF- I on the periodontal ligament cells to use as a regeneration promoting agent of periodontal tissue. Human periodontal ligament cells were obtained from periodontal tissue explants culture of the first premolar tooth extracted for the orthodontic treatment. Cells were cultured in Dulbecco's modified Eagle medium(DMEM) with 10% fetal bovine serum. Fourth to seventh passage cells were plated in 24 well tissue culture plates and medium changed to serum-free medium prior to addition of growth factors. Cell proliferation was measured by the incorporation of $[^3H]-thymidine$ into DNA, Protein synthesis was determined by measurement of $[^3H]-proline$ incorporation into collagenase-digestible protein(CDP) and noncollagenous protein(NCP) according to the method of Peterkofsky and Diegelmann (1971), And alkaline phosphatase activity was measured as one parameter of osteoblastic differentiation. The results were as follows : The DNA synthetic activity was increased in a dose-dependent manner with IGF- I except for 0.1ng/ml concentration of IGF- I At the concentration of 10, 100ng/ml, IGF- I significantly increased the DNA synthetic activity(P<0.05) The total protein, collagen and noncollagen synthesis was increased in a dose-dependent manner with IGF- I except for 0.1ng/ml concentration of IGF- I. At the concentration of 1, 10, 100ng/ml, IGF- I significantly increased the total protein, collagen and noncollagen synthesis activity(P<0.95, P<0.001). The % of collagen was not effected according to the concentration of IGF- I. The alkaline phosphatase activity was increased in a dose-, time-dependent manner with IGF- I (10, 100ng/ml). In conclusions, the present study shows that IGF- I has a potentiality to enhance the DNA synthesis of periodontal ligament cells with including the increase of the total protein and collagen synthetic activity. The use of IGF- I to mediate biological stimulation of periodontal ligament cells shows promise for future therapeutic applications.

• Journal of Life Science
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• v.24 no.3
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• pp.297-303
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• 2014

The effects of Eisenia bicyclis extracts on osteoblast differentiation and osteoclast formation were investigated. The proliferation of MC3T3-E1 osteoblastic cells was tested in an MTT assay. Treatment with E. bicyclis ethanol extract increased cell proliferation by approximately 128% at a concentration of 10 ${\mu}g/ml$. The ALP activities in the MC3T3-E1 cells was 179% higher when the E. bicyclis ethanol extract was processed at a concentration of 50 ${\mu}g/ml$. The proliferation of RAW 264.7 osteoclastic cells decreased significantly in response to treatment with the E. bicyclis extracts. Moreover, the proliferation of the RAW 264.7 osteoclastic cells treated with E. bicyclis hot water extract decreased by nearly 80%. In addition, the E. bicyclis extract reduced the number of tartrate-resistant acid phosphatase-positive (TRAP+) multinucleated cells from osteoclastic RAW 264.7 cells. These results indicate that E. bicyclis extracts have an anabolic effect on bone through the promotion of osteoclast differentiation and suggest that the extracts could be used in the treatment of common metabolic bone diseases.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.7
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• pp.929-936
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• 2005

The purpose of this study was to examine the ability of alkaline phosphatase (ALP) synthesis of MC3T3-E1 cells when above edible sources, Solidago virga-aurea var. gigantea Miq. root (SVR) extracts, were supplimented. MC3T3-E1 cells were cultured with $\alpha-MEM$(vehicle control), dexamethasone and genestein (positive control), and SVR extracts for 27 days. The effects of SVR MeOH extracts and its fractions on cell proliferation were measured by MTT assay. At 10, 100${\mu}g/mL$ of SVR methanol extract treated, that were elevated of cell proliferation to 140 and $120\%$ via vehicle control, respectively. And then ALP synthesis was measured by spectrophotometer for enzyme activity and by naphthol AS-BI staining for morphometry at 3, 9, 18, and 27th day. As the results, every extracts and fractions were promoted ALP activity by time course at 1, 10, 100${\mu}g/mL$, except n-hexane and chloroform fractions. Remarkably, the MeOH extracts were increased ALP activity more than 4.4 times compared with vehicle control, 2.2 times via positive control at 27th day (p<0.05). The SVR MeOH extracts treated cells, especially at a concentration of 10${\mu}g/mL$, showed remarkably higher than vehicle-treated control cells of mineralization which were checked by Alizarin red staining. These results indicate that SVR methanol extract have an induction ability of proliferation and differentiation on osteoblast.

• Journal of the korean academy of Pediatric Dentistry
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• v.30 no.2
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• pp.308-319
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• 2003

Mechanical forces are known to have an effect on bone formation, maintenance and remodeling, and there is evidence that the development of the mandibular condyle in the rat or mouse is influenced by altered functional force. However, studies are lacking in molecular-biologic mechanism such as the identification of differentiation factor induced from functional force. Here a mouse model was used to investigate the functional stress-responsive gene or factors which is related to the altered force by comparing the expression genes of functional state and hypo-functional state of the mouse mandible. ICR mice were provisioned with either a soft, mushy diet (soft-diet group) or hard rat pellets (hard-diet group) beginning at weaning for the alteration of functional force and subsequently sacrificed at 89 days of age. Incisor of mice in group 1 were trimmed twice a week to reduce occlusal forces. After killing the animals, mandibular bone including condyle were collected for RNA extraction, subtractive hybridization, northern blot analysis and mRNA in-situ hybridization. The results as follows; 1. A total of 39 clones were sequenced, and 11 individual sequence types were subsequently identified by subtractive hybridization, as 28 clones were represented twice in the analyzed sets. 2. Consequently four candidate clones, FS-s (functional stress-specific)2, -5, -18, and -22 were identified and characterized by homolgy search and northern analysis. Four of these clones, FS-s2, -5, -18, and -22, were shown to be expressed differentially in the hard-diet group. 3. Histologic sections showed that osteoblastic activity along the bone trabeculae and active bone remodeling were significantly lower in soft than in hard diet animals. A soft diet seems to enable a longer period of endochondral ossification in the mandibular condyle. 4. Although the mRNAs of FS-s2, -5, -18, and -22 were expressed rarely by cells of the soft-diet group, highest expression was detected in the cells of the hard-diet group. Together with the above results, it is suggested that FS-s2, -5, -18, and -22 could act as an important factors controlling the tissue changes in response to functional stress. The exact functional significance of these findings remains to be established.