• Journal of Periodontal and Implant Science
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• v.35 no.2
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• pp.277-288
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• 2005

There is a potential role of collagenase-3 in alveolar bone loss and periodontal disease progression, we need to develope or find chemotherapeutic drugs or herbal agents which may regulate the expression of MMP-13. Ginseng saponin, one of the major components of Korea ginseng(panax ginseng) root, has many various biologic effects, such as cytotoxic effect, tumoricidal effects, cytokine regulations, and protein biosynthesis effect. The purpose of this study was to determine the effects of Korea red ginseng saponin on MMP-13 gene expression in osteoblasts. The experimental groups were cultured with ginseng saponin in concentration of 1.0, 10, 25, 50, 100, 250 and $500{\mu}g/ml$ for MTT assay. Primary rat calvarial cells were pre-treated for 1 hour with ginseng saponin(100 ${\mu}g/ml$) and then stimulated with $IL-1{\beta}(1.0ng/ml)$ and PTH(10 nM). MMP-13 gene expression was evaluated by RT-PCR. The results were as follows: Ginseng saponin was cytotoxic to osteoblast at concentration exceeding $250{\mu}g/ml$ for longer than 24 hours in tissue culture(p<0.01). In RT-PCR analysis, steady state MMP-13 mRNA levels were increased approximately 350% by $IL-1{\beta}$, and 400% by PTH when normalized to untreated control. $IL-1{\beta}-indued$ MMP-13 mRNA expression was reduced 50% by pretreatment with ginseng saponin. But ginseng saponin didn't inhibit MMP-13 expression from PTH stimulated cells. This results suggest that ginseng saponin Inhibit $IL-1{\beta}-indued$ MMP-13 mRNA expression.

• International Journal of Stem Cells
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• v.11 no.2
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• pp.177-186
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• 2018

Background and Objectives: Glial scarring and inflammation after spinal cord injury (SCI) interfere with neural regeneration and functional recovery due to the inhibitory microenvironment of the injured spinal cord. Stem cell transplantation can improve functional recovery in experimental models of SCI, but many obstacles to clinical application remain due to concerns regarding the effectiveness and safety of stem cell transplantation for SCI patients. In this study, we investigated the effects of transplantation of human mesenchymal stem cells (hMSCs) that were genetically modified to express Olig2 in a rat model of SCI. Methods: Bone marrow-derived hMSCs were genetically modified to express Olig2 and transplanted one week after the induction of contusive SCI in a rat model. Spinal cords were harvested 7 weeks after transplantation. Results: Transplantation of Olig2-expressing hMSCs significantly improved functional recovery in a rat model of contusive SCI model compared to the control hMSC-transplanted group. Transplantation of Olig2-expressing hMSCs also attenuated glial scar formation in spinal cord lesions. Immunohistochemical analysis showed that transplanted Olig2-expressing hMSCs were partially differentiated into Olig1-positive oligodendrocyte-like cells in spinal cords. Furthermore, NF-M-positive axons were more abundant in the Olig2-expressing hMSC-transplanted group than in the control hMSC-transplanted group. Conclusions: We suggest that Olig2-expressing hMSCs are a safe and optimal cell source for treating SCI.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.36 no.11
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• pp.1081-1090
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• 2012

This study aims to track the longitudinal alteration pattern on the trabecular bone microarchitecture at tibial epiphysis induced by T-OA over time using in vivo micro computed tomography (${\mu}CT$). Ten SD rats were divided into control (n = 5) and T-OA (n = 5) groups. Anterior cruciate ligament transaction was performed for the T-OA group. The results showed that the alteration pattern on the trabecular bone microarchitecture at tibial epiphysis in the T.OA group was definitely different compared with that in the CON group from 0 to 8 weeks (approximately 4-16%, P > 0.05). In particular, a difference was observed in the bone formation and density distributions over time (from 0 or 4 to 8 weeks; approximately 5.15%, P < 0.05). An improved understanding of the alteration pattern on the trabecular bone microarchitecture at tibial epiphysis may assist in developing more targeted treatment interventions for T-OA.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.41
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• pp.52.1-52.8
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• 2019

Background: A compact passive oxide layer can grow on tantalum (Ta). It has been reported that this oxide layer can facilitate bone ingrowth in vivo though the development of bone-like apatite, which promotes hard and soft tissue adhesion. Thus, Ta surface treatment on facial implant materials may improve the tissue response, which could result in less fibrotic encapsulation and make the implant more stable on the bone surface. The purposes of this study were to verify whether surface treatment of facial implant materials using Ta can improve the biohistobiological response and to determine the possibility of potential clinical applications. Methods: Two different and commonly used implant materials, silicone and expanded polytetrafluoroethylene (ePTFE), were treated via Ta ion implantation using a Ta sputtering gun. Ta-treated samples were compared with untreated samples using in vitro and in vivo evaluations. Osteoblast (MG-63) and fibroblast (NIH3T3) cell viability with the Ta-treated implant material was assessed, and the tissue response was observed by placing the implants over the rat calvarium (n = 48) for two different lengths of time. Foreign body and inflammatory reactions were observed, and soft tissue thickness between the calvarium and the implant as well as the bone response was measured. Results: The treatment of facial implant materials using Ta showed a tendency toward increased fibroblast and osteoblast viability, although this result was not statistically significant. During the in vivo study, both Ta-treated and untreated implants showed similar foreign body reactions. However, the Ta-treated implant materials (silicone and ePTFE) showed a tendency toward better histological features: lower soft tissue thickness between the implant and the underlying calvarium as well as an increase in new bone activity. Conclusion: Ta surface treatment using ion implantation on silicone and ePTFE facial implant materials showed the possibility of reducing soft tissue intervention between the calvarium and the implant to make the implant more stable on the bone surface. Although no statistically significant improvement was observed, Ta treatment revealed a tendency toward an improved biohistological response of silicone and ePTFE facial implants. Conclusively, tantalum treatment is beneficial and has the potential for clinical applications.

• Journal of Periodontal and Implant Science
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• v.50 no.2
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• pp.121-131
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• 2020

Purpose: Dental implant-associated medication-related osteonecrosis of the jaw has been frequently reported in patients administered bisphosphonates (BPs) to prevent osteoporosis. The aim of this study was to investigate the effect of intermittent administration of parathyroid hormone (PTH) on peri-implant bone in the maxillae of ovariectomized rats systemically administered BPs. Methods: Thirty 8-week-old female Sprague-Dawley rats were randomly divided into 3 groups. The OVX-ZP group included ovariectomized rats administered 60 ㎍/kg of zoledronate once a week for 6 weeks and 30 ㎍/kg PTH after implant installation. The OVX-Z group included ovariectomized rats administered 60 ㎍/kg of zoledronate once a week for 6 weeks and saline after implant installation, and the control group included rats that underwent a sham operation and were then administered saline. Rats were sacrificed 4 weeks after implant placement for histomorphometric and micro-computed tomography (CT) analyses. Results: The average bone area percentage was greater in the OVX-ZP group than in the OVX-Z group (53.4%±4.0% vs. 28.9%±9.5%, P=0.01). The bone-to-implant contact ratio was 50.8%±1.4% in the OVX-ZP group and 16.9%±2.4% in the OVX-Z group (P=0.012). The average bone volume ratio as shown on micro-CT was 31.3%±19.8% in the OVX-ZP group and 19.4%±9.3% in the OVX-Z group (P=0.045). The OVX-ZP and OVX-Z groups displayed similar trabecular thickness (0.06±0.004 mm vs. 0.06±0.002 mm) (P>0.05) and trabecular separation (0.21±0.02 mm vs. 0.29±0.13 mm) (P>0.05). However, the number of trabeculae in the OVX-ZP group was significantly higher than that in the OVX-Z group (4.3±1.33/㎣ vs. 2.2±0.19/㎣) (P=0.024). Conclusions: The present findings indicate that intermittently-administered PTH can promote peri-implant bone formation and suggest that PTH administration may aid in effective treatment for medication-related osteonecrosis of the jaw after dental implantation.

• Molecules and Cells
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• v.38 no.7
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• pp.643-650
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• 2015

The use of conditioned medium from mesenchymal stem cells may be a feasible approach for regeneration of bone defects through secretion of various components of mesenchymal stem cells such as cytokines, chemokines, and growth factors. Mesenchymal stem cells secrete and accumulate multiple factors in conditioned medium under specific physiological conditions. In this study, we investigated whether the conditioned medium collected under hypoxic condition could effectively influence bone regeneration through enhanced migration and adhesion of endogenous mesenchymal stem cells. Cell migration and adhesion abilities were increased through overexpression of intercellular adhesion molecule-1 in hypoxic conditioned medium treated group. Intercellular adhesion molecule-1 was upregulated by microRNA-221 in mesenchymal stem cells because microRNAs are key regulators of various biological functions via gene expression. To investigate the effects in vivo, evaluation of bone regeneration by computed tomography and histological assays revealed that osteogenesis was enhanced in the hypoxic conditioned medium group relative to the other groups. These results suggest that behavioral changes of endogenous mesenchymal stem cells through microRNA-221 targeted-intercellular adhesion molecule-1 expression under hypoxic conditions may be a potential treatment for patients with bone defects.

• Journal of Periodontal and Implant Science
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• v.27 no.1
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• pp.129-150
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• 1997

The purpose of this study was to evaluate the effects of tetracycline(TC}, flurbiprofen, and PDGF-BB loaded biodegradable membranes on the cell-attachment, the activity of loaded PDGF-BB, in vivo release kinetics, and guided bone regenerative potentials. To evaluate the cell attachment to membranes, the number of gingival fibroblasts attached to each membrane(10% TC, 10% flurbiprofen, $200ng/cm^2$ PDGF-BB loaded membranes, drug-unloaded membrane) was counted by coulter counter and the morphologic pattern of attached cells was examined under SEM. To determine whether the activity of loaded PDGF-BB is sustained, the cellular growth and survival rate of gingival fibroblasts was used for both standard PDGF-BB and loaded PDGF-BB. For evaluation of in vivo release kinetics, drug-loaded membranes were implanted on the dorsal skin of the rats. On 1, 3, 7, 10, 14, 21, and 28 days after implantation, the amount of remaining drugs were measured by HPLC assay for TC and flurbiprofen, and by ${\gamma}-scintillation$ counter for $PDGF-BB^{1125}$. For evaluation of guided regenerative potential, the amount of new bone in the calvarial defect(5mm in diameter) of the rat was measured by histomorphometry 1 and 2 weeks after implantation of membranes. The number of cells attached to the PDGF-BB loaded membrane was largest as compared with the other mernbranes.(p< 0.05) The activity of loaded PDGF-BB was not significantly different from the activity of standard PDGF-BB.(p<0.05) After initial burst release of drug during the first 24 hours, drugs were gradually released for 4 weeks. Especially the release rate of PDGF-BB was nearly constant during 4 weeks. PDGF-BB loaded membranes(200, $400ng/cm^2$) were effective in guided bone regeneration as compared with drug-unloaded membrane. These results implicate that drug-loaded biodegradable membranes might be a useful for guided bone regeneration.

• 한국노년학
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• v.31 no.2
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• pp.303-315
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• 2011

The purpose of this study was to investigate effect of resistance training on BMD and bone metabolism related markers in aging rats. Thirty male Spraugue-Daweley rats were divided into sedentary (CON; n=10 ) non-load resistance trained(NLRTG; n=10), and load resistance trained(LRTG; n=10) groups at the age of 64 weeks. The rats in the resistance training groups((NLRTG and LRTG) performed the tower climbing exercise 4 times a week. The LRTG groups were conditioned to climb a vertical ladder with weights appended to their tail 4 days/wk for 12 wks. After 12 weeks of exercise, serum osteocalcin, bone mineral density (BMD), breaking force, ash, Ca, and P in the femur were measured. After training, serum osteocalcin (OC) was significantly (p < 0.05) higher in both LRTG and NLRTG when compared to Control. Right femur BMD was significantly (p < 0.05) greater for LRTG when compared to both NLRTG and Control with no significant difference between NLRTG and Conrtol. The breaking force of femur was significantly (p < 0.05) greater for LRTG and NLRTG when compared to Control. The Ash, Ca, content of femur were significantly increased in resistance training groups than control group. These results suggest that the increase in bone mineral density induced by resistance training is mediated by changes in bone microarchitecture as well as training intensity and osteocalcin.

• 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.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.2
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• pp.324-330
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• 2004

The purpose of this study was to investigate the effects of Porphyra tenera (PT) extracts on formation of collagen cross-link in ovariectomized rats. From day 3 until 42 after the ovariectomy, Sprague-Dawley female rats were randomly assigned to the following groups : sham-operated rats (Sham), ovariectomized control rats (OVX-control), ovariectomized rats supplemented with PT at 50 mg/kg bw/day (OVX-PT5O), 200 mg/kgbw/day (OVX-PT200). The PT ethanol extracts were orally administrated 1 mL per day. Body weight gain, food intake and food efficiency ratio were significantly different among the groups. The change of collagen content was studied in lung, bone, cartilage and skin of ovariectomized rats. The effects of PT extracts on the amount of collagen were examined by measuring the hydroxyproline, which is a specific amino acid existing in collagen. Pyridinoline is pyridinium cross-link formed in the mature form of collagen from lysine and hydroxylysine residues. Pyridinoline content was analyzed by HPLC. Pyridinoline content in bone collagen was decreased by ovariectomy but supplementation with the PT extracts was similarly increased to Sham. These results suggest that the PT supplementation could decrease bone loss in postmenopausal women.