地塞米松对成牙骨质细胞增殖和矿化功能的调节作用

The effect of Dexamethasone on the proliferation and mineralization of cementoblasts in vitro

目的:研究不同浓度地塞米松对成牙骨质细胞增殖、矿化能力的影响。方法:本研究设3个实验组和1个对照组,对体外培养的成牙骨质样细胞OCCM-30分别加入1×10-5mol/L、1×10-6mol/L、1×10-7mol/L的地塞米松作为实验组,对照组不加药。72h后提取细胞总RNA,用实时荧光定量PCR(Q-PCR)方法检测成牙骨质细胞矿化相关基因mRNA表达的变化。CCK-8法检测地塞米松对成牙骨质细胞增殖的影响,采用碱性磷酸酶活性检测、茜素红染色对地塞米松作用后成牙骨质细胞生物学特性作初步观察。结果:地塞米松在高浓度时有抑制成牙骨质细胞增殖的作用。和对照组相比,实验组ALP活性增高,矿化结节形成明显增多,Q-PCR结果显示与细胞矿化相关基因ALP、BSP、OCN、Runx-2 mRNA表达与对照组相比明显增高。结论:地塞米松可以增加成牙骨质细胞矿化功能,并可能由此影响牙根吸收和修复过程。

Objective To investigate the effect of different concentration of dexamethasone on the mineralization and proliferation to cementoblasts in vitro. Methods A murine immortalized cementoblast cell line （OCCM-30） was cultured in the presence of dexamethasone at three concentrations：l ×10^-5mol/L,1 ×10^-6mol/L and 1 ×10^-7mol/L. After 72 hours, total RNA was isolated,and mRNA levels for bone/cementum markers,including alkaline phosphotase （ALP）,bone sialoprotein （BSP）,osteocalcin （OCN）,and runt-related transcription factor-2 （Runx2） were investigated by real- time quantitative reverse transcription-polymerase chain reaction （Q-PCR）. Alkaline phosphotase activity and the proliferation of cementoblast were also detected.Mineral nodule formation was assayed on day 8 using Alizarin red staining. Results The proliferation of OCCM-30 treated by dexamethasone at 1×10^-4 mol/L was significantly significantly declined than that of control. Mineralized tissue markers were strongly regulated by dexamethasone, with an almost six-fold increase in BSP transcripts and significant increases in ALP,OCN and Runx-2 mRNA expressions. Dexamethasone treatment markedly stimulated alkaline phosphotase activity and cementoblast -mediated biominerafization in vitro compared to untreated cells. Conclusion Dexamethasone can promote the mineralization of the cementoblasts.These results support the promising applications of dexamethasone in therapies aimed at regenerating periodontal tissues lost as a consequence of disease.