胞内信号转导分子LIM矿化蛋白1在人牙髓细胞体外矿化过程中表达的实验研究

Expression of LIM Mineralization Protein-1 during Mineralization by Human Dental Pulp Cells in Vitro

目的:研究胞内信号转导分子LIM矿化蛋白1在人牙髓细胞体外矿化过程中的表达。方法:利用组织块法体外培养人牙髓细胞,实验组培养液中加入矿化诱导剂,对照组不加矿化诱导剂。培养14d后,免疫细胞化学检测牙本质涎蛋白的表达;von kossa染色检测矿化结节的形成。培养期间,采用半定量RT-PCR技术监测LIM矿化蛋白1及碱性磷酸酶的表达,SPSS11.0软件分析结果。结果:培养14d,实验组牙本质涎蛋白免疫细胞化学呈阳性表达,von kossa染色阳性,矿化结节形成;对照组牙本质涎蛋白表达阴性,von kossa染色阴性。RT-PCR结果显示碱性磷酸酶及LIM矿化蛋白1在实验组和对照组各时段均表达。培养期间,实验组LIM矿化蛋白1的表达显著性高于对照组,其中培养第2天及9天时表达分别达到两个高峰,约为对照组的1.8倍及3.0倍。培养期间,碱性磷酸酶的表达显著性增高,其中培养14d时约为对照组的2.0倍。结论:首次发现LIM矿化蛋白1与人牙髓细胞的体外矿化过程相关,提示LIM矿化蛋白1可能在牙髓细胞的分化及矿化中发挥一定作用。

Objective： To investigate the expression pattern of LIM mineralization protein - 1 during mineralization by cultured human dental pulp ceils. Methods： Human dental pulp ceils were differentiated via culturing in the presence of dexamethasone, asorbic acid and β - glycerophosphate for dentin - like mineralized nodule formation, characterized by yon kossa staining and by immunocytochemistry of dentin sialoprotein. Expression of LIM mineralization protein - 1 and alkaline phosphatase was analyzed by reverse transcriptase- polymerase chain reaction on days 0, 1,2, 3, 5, 7, 9, 11, 14, 21, 28. Results： During the mineralization, LIM mineralization protein - 1 and alkaline phosphatase were expressed at every time point, generally held at a statistically significantly higher level compared with the control. For LIM mineralization protein - 1, 1.8 - fold increase on day 2 and 3.0 - fold increase on day 9 ; for alkaline phosphatase, 2.0 - fold increase peak on day 14. Conclusion： LIM mineralization protein - 1 was firstly found to be involved in the mineralization of human dental pulp cells. It is tentatively concluded that LIM mineralization protein - 1 plays a role in the differentiation and mineralization of human dental pulp cells.