Effects of compressive stress on the expression of M-CSF, IL-1beta, RANKL and OPG mRNA in periodontal ligament cells / 대한치과교정학회지

OBJECTIVE: The aim of this study was to determine if human PDL cells can produce osteoclastogenic mRNA and examine how compressive stress affects the expression of osteoclastogenic mRNA in human PDL cells. METHODS: Human PDL cells were obtained from biscupids extracted for orthodontic treatment. The compressive force was adjusted by increasing the number of cover glasses. PDL cells were subjected to a compressive force of 0.5, 1.0, 2.0, 3.0 or 4.0 g/cm2 for 0.5, 1.5, 6, 24 or 48 hours. Reverse transcription polymerase chain reaction (RT-PCR) analysis was performed to examine levels of M-CSF, IL-1beta, RANKL, OPG mRNA expression. RESULTS: Human PDL cells could produce M-CSF mRNA. Human PDL cells under compressive stress showed increased M-CSF, IL-1beta and RANKL mRNAs expression in a force (up to 2 g/cm2) and time-dependent manner. However, OPG mRNA expression was constant regardless of the level and duration of stress. CONCLUSIONS: Continuous compressive stress induced the mRNA expression of osteoclastogenic cytokines including M-CSF, RANKL, IL-1beta in PDL cells. Together with an unchanged OPG mRNA level, these results suggest that compressive stress-induced osteoclastogenesis in vivo is partly controlled by M-CSF, RANKL and IL-1beta expression in PDL cells.

Effects of enamel matrix derivatives on biologic activities of human periodontal fibloblasts to demineralized root surface / 대한치주과학회지

PURPOSE: The aim of this study was to investigate the effects of EMD on demineralized root surface using human periodontal ligament cells and compare the effects of root conditioning materials(tetracycline(TCN), EDTA). MATERIAL AND METHODS: Dentin slices were prepared from the extracted teeth and demineralized with TCN and EDTA. Demineralized dentin slices were incubated at culture plate with 25, 50 and 100 microgram/ml concentration of EMD. Cell attachment, alkaline phosphatase activity test, protein synthesis assay and scanning electronic microscopic examination were done. RESULTS: Cells were attached significantly higher in EMD treated group at 7 and 14 days. Cell numbers were significantly higher in EMD treated group. Alkaline phosphatase activity was significantly higher in EMD treated group at 7 and 14 days. Protein synthesis was significantly higher in EMD treated group at 7 and 14 days. CONCLUSION: Enamel matrix derivatives enhance the biologic activities of human periodontal ligament cells on demineralized root surface and its effects are dependent on the concentration of EMD.

Osteogenic activity of an adenovirus expressing BMP-2 on Human Periodontal Ligament cells / 대한치주과학회지

The regeneration of lost periodontal tissue is a major goal of therapy. Periodontal ligament cell(PDL) is a specialized connective tissue that connects cementum and alveolar bone to maintain and support teeth in situ and preserve tissue homoeostasis. Bone morphogenetic proteins(BMPs) have shown much potential in the reconstruction of the periodontum by stimulate new bone and new cementum formation. Limitiations of BMP administration to periodontal lesions is high dose delivery, BMP transient biological activity, and low bioavailability of factors at the wound site. Gene delivery method can be alternative treatment strategy to deliver BMPs to periodontal tissue. The purpose of this study is to investigate efficiency of BMP-2 gene delivery with cell-based therapy using PDL cells. PDL cell were transduced with adenoviruses encoding either BMP-2 or Lac-Z gene. To evaluate osteogenic activity of expressed BMP-2 on PDL cells, we investigated secreted BMP-2, cellular activity, ALPase, produced mineralized nodules. To evaluate collagen scaffold as carrier for transduced cell delivery, we examined morphology and secreted BMP-2 of transducd PDL cells on it. BMP-2 transducd PDL cells produced higher levels of BMP-2, ALPase, mineralized nodules than non transduced cells. Cellular activity of transduced cells was showed similar activity to non transduced cells. Transduce cells attached on collagen scaffold secreted BMP-2 at 7day and was showed similar morphology to non transduced cells. These results demonstrated that transduced PDL cells produced biologically active BMP-2 and collagen scaffold could be carrier of transducd cells.

Effect of Citric Acid and Tetracycline HCl Root Conditioning on rhBMP-2 on Human Periodontal Ligament Fibroblast and Osteoblast Cell / 대한치주과학회지

The goal of periodontal treatment is predictable periodontal regeneration. But until now, many products including GTR materials and growth factors are beyond of complete regeneration. BMP can induce ectopic bone formation when implanted into sites such as rat muscle and can greatly enhance healing of bony defects when applied exogenously. BMP can promote periodontal regeneration by their ability to stimulate new bone and new cementum formation. But little is known about optimal conditions required for the application. Root conditioning is used for bioactive root change so altered root surface provides a substrate that promotes chemotaxis, migration and attachment of peridontal cells encouraging connective attachment to the denuded root surface. The aim of this study is to investigate whether the acid conditioning change effect of rhBMP-2 on human periodontal ligament cell and osteoblast cell line. 288 periodontally involved root dentin slices are divided into 6 groups, each 48, 1)control, 2)treated with BMP, 3)treated with citric acid 4)treated with citric acid+BMP 5)treated with tetracycline 6)treated with TC+BMP. Each group was devided half, so 12 root dentin slices were seeded with periodontal ligament cells and 12 were seeded with osteoblasts. At day 2 and 7, cell number, protein assay, ALP activity was measured. To investigate morphology of cultured cells, SEM was employed. Statistical analysis was performed with SPSS 8.0 either t-test or ANOVA test. The results are ; Protein assay and cell number was slightly decreased in CA+BMP group compared to CA group but it was not statistically significant and ALP activity was much more increased in CA+BMP group compared to CA group so there was no statistically significance between BMP and CA+BMP group and statistically significant compared to control group. Cell number and protein assay was slightly increased in TC group and ALP activity was much less than BMP group and CA group. Cell number and protein and ALP activity was not much increased in TC+BMP group. TC group and TC+BMP group showed cell morphology change in SEM. This results suggested that application of root surface with citric acid before BMP treatment might give better result in periodontal regeneration.

Mitogenic effects of nicotine to human periodontal ligament(PDL) cells in vitro / 대한치과교정학회지

Nicotine is one of the major components of cigafette smoking which causes various systemic and local diseases to human body. Mitrogenic effects of nicotine to systemic disease are interesting factors in the results of cellular proliferation especially to vascular and pulminary tissus or cells. The study of local effects concerns with destruction of tissue and delayed healing rate after various surgicla treatment. Platelet-Derived Growth factor(PDGF) and Insulin-like growth factor(IGF) are known as major mitogens to human PDL cells. The purpose of this studywas to investgate the mitogenic effects of nicotine to human PDL cells. We studied the expression of PDGF-alpha receptor, PDGF-betareceptor, and IGF-1 receptor mRNA form the nicotine treated human PDL cells by northern analysis. The experimental groups were divided into different serum(1%, 10%) and nicotine(100ng/ml, 1000ng/ml) condentrations and each group was studied by time course. The results of this study showed upregulation of PDGF-alpha, beta receptor and IGF-1 receptor mRNA at 100ng/ml nicotine concentration and 10% serum group to the time course. These results suggest that physiologically attainable nicotine concentrations may stimulate mitogenic gene synthesis to human PDL cells in vitro.