| Background and objective:Orthodontically induced inflammatory root resorption is a kind of side effect of Orthodontic tooth movement. How to prevent and treat OIIRR become a research hotspot in recent years. Because Cementoblast plays an important role in root formation, repair of periodontal tissue regeneration and root absorption, so it become the object of numerous mechanics research.BMP2 is a powerful inducers of bone formation,and it plays an important role in root development. In the pilot study,we found that BMP2 was expressed efficiently in Cementoblast. BMP2 can be highly purified by mechanical stress. And at the same time, the expression of Smad 1/5/8 protein was also changed. The results suggested that BMP2/Smads signal pathway may be involved in the regulation of stress stimulation on cementoblasts functions. Sclerostin (SOST) is a secreted glycoprotein,codyed by the gene of sclerosteosis. As an inhibitor of bone formation, Sclerostin inhibits bone formation which was induced by BMP. But the regulation of BMP2 in Cementoblast on the expression of SOST is not clear.This research is to explore the regulatory role of BMP2 in the expression of sclerostin through enhance the BMP2 signal or inhibit it,and than verify that the BMP/Smads pathway is the main way of mediated sclerostin expression. The experiment was divided into three parts.Part I. The effects of different concentrations of BMP2 on the expression of sclerostin in OCCM30.Objective:To explore the effects of different concentrations of BMP2 on the expression of sclerostin (SOST) in OCCM30.Methods:OCCM-30 were cultured in BMP2 of different concentration as Ong/ml,50ng/ml, 100ng/ml cells.And the cells were collected at third days, fifth days,and seventh days. Western blot was done to detect the sclerostin levels,and SOST mRNA was observed by real-time quantitative PCRResults:The results of RT-PCR and Western blot showed that, BMP2 up regulates sthe expression of SOST in a concentration dependent manner.And with time increased, SOST expression increases.Conclusion:the expression of BMP2 up-regulated the expression of SOST, BMP2 increased with the incubation time, the expression of SOST increased.Part Ⅱ. The effect of different concentrations of dorsomorphin, PD98059, SB202190 on the proliferation of OCCM30Objective:To explore the effects of different concentrations of dorsomorphin, PD98059, SB202190 on the proliferation of OCCM30, and select the best inhibitor concentration for the subsequent experiments.Methods:OCCM30 were cultured with different concentrations of dorsomorphin, PD98059,and SB202190, and the concentration of them were set to 2μM,4μM,6μM,8μM, 10μM,12μM. CCK test cell proliferation.Results:The proliferation of OCCM30 was inhibited by the different concentration of dorsomorphin.And the higher concentration of dorsomorphin, the inhibition was more obvious.The proliferation of OCCM30 was not inhibited significantly by SB202190 and PD98059 in 24h and 48h, but it was inhibited in 72h. And the higher concentration of PD98059 and SB202190, the inhibition was more obvious.PartⅢ The research on expression of Sclerostin/SOST mediated by BMP/smad in OCCM-30Objective:To explore the expression of Sclerostin/SOST mediated by BMP/smad in OCCM-30.Methods:The experiment was divided into five groups of A, B, C, D, E. A:control, without BMP2 or other drugs.B:BMP2; C: BMP2+dorsomorphin; D:BMP2+SB202190;and E:BMP2+PD98059. OCCM30 were pretreated by these drugs for 3 days and 5 days.Then Western blot was done to detect the sclerostin levels,and SOST mRNA was observed by real-time quantitative PCR.Results:Compared with BMP2 group, sclerostin levels of BMP2+dorsomorphin group, BMP2+SB202190 group and BMP2+ PD98059 were lower. And the sclerostin level in BMP2+dorsomorphin group decreased most.Conclusion:The up regulation of sclerostin (SOST) by BMP2 in OCCM-30 was mainly mediated by BMP signal pathway. |
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