ABSTRACT
No abstract available.
Subject(s)
Animals , Rats , Periodontal Ligament , PhosphotransferasesABSTRACT
It has been focused on the importance of the host inflammatory response in periodontal pathogenesis and progression, treatment has been introduced to control the host response and the method, which diminishes production and activity of MMP by doxycycline, has been used in periodontal field. MMP is a proteolytic enzyme which plays a major role in tissue destruction and MMP-1 is secreted in the periodontally healthy tissue, while MMP-8, 9, 13, etc in the inflammatory state. Among these, MMP-13 has been discovered lately and reported to degrade primarily type II collagen. Periodontal ligament (PDL) cell plays a role in destruction of periodontal tissue. This study was to evaluate the effect of doxycycline and mefenamic acid, non-steroidal antiinflammatory drug on MMP-13 mRNA expression in the rat PDL cell. Doxycycline concentration of 1~100 microgram/ml was added rat PDL cell and cell activity was measured by MTT assay at day 1 and 3. MMP-13 gene expression was evaluated by RT-PCR after PDL cells were pre-treated for 1 hour with doxycycline (50 microgram/ml) alone or with mefenamic acid (10(-6)M), then added IL-1beta(1.0 ng/ml) and incubated for 16 -18 hours. The results are as follows: 1. Cell activity decreased significantly at 24 and 72 hours in 100 microgram/ml (p<0.05). 2. Level of MMP-13 mRNA was in 202% increase by IL-1beta and in pre-treating doxycycline group, expression of IL-1beta induced MMP-13 mRNA was inhibited by 31% than IL-1beta treated only. 3. Mefenamic acid did not inhibit on the expression of IL-1beta induced MMP-13 mRNA, while mefenamic acid in combination with doxycycline inhibited the expression by 41% compared to only IL-1beta stimulation. These results suggest that doxycycline synergistically inhibit the expression of IL-1beta induced MMP-13 mRNA in combination with mefenamic acid.
Subject(s)
Animals , Rats , Anti-Inflammatory Agents, Non-Steroidal , Collagen Type II , Doxycycline , Gene Expression , Mefenamic Acid , Periodontal Ligament , RNA, MessengerABSTRACT
Periodontal therapy has dealt primarily with attempts at arresting progression of disease, however, more recent techniques have focused on regenerating the periodontal ligament having the capacity to regenerate the periodontium. Recombinant human bone morphogenetic protein-7(rhBMP-7) can differentiate the osteoprogenitor cells and induce bone formation. The purpose of this study was to evaluate the effect of BMP-7 on rat periodontal ligament cells differentiation, in vitro. In the control group, cells was cultured with DMEM media. In the experimental groups, cells were cultured with rhBMP-7 in concentration of 10, 25, 50 and 100 ng/ml. Each group was characterized by examining alkaline phosphatase activity at 3 and 5 days of culture and the ability to produce mineralized nodules of rat calvarial cells at 14 days of culture. Synthesis of type I collagen(COL-I), osteocalcin(OCN), and bone sialoprotein (BSP) was evaluated by RT-PCR at 7 days of culture. Activation of Smad proteins and p38 MAP kinase was determined by western blot analysis of the cell lysates. Alkaline phosphatase activity was significantly increased in the concentration of BMP-7 50 ng/ml and 100 ng/ml compared to the control(p<0.05). The mineralized bone nodule formation was greater with addition of 50 ng/ml and 100 ng/ml BMP-7 than the control(p<0.01). In 7 days' culture, the expressions of COL-1, BSP, and OCN was increased by BMP-7 in concentration of 10 ng/ml~100 ng/ml. In western blot analysis, BMP-7 treated culture cells expressed Smad 1,5,8 in dose-dependent manner, whereas BMP-7 did not activate phosphorylated form of p38 MAP kinase. These result suggested that BMP-7 stimulate rat periodontal ligament cells to differentiate toward osteoblast phenotype and increase bone matrix production by activation of BMP-Smad pathway.