中文摘要：

目的：探讨人牙髓细胞（hDPCs）经矿化诱导向成牙本质细胞分化过程中丝氨酸蛋白酶HtrA1、转化生长因子（TGF）-β1和Smad3的表达情况。方法：建立体外培养的hDPCs矿化诱导模型,根据矿化时间分为0d、7d、14d、21d、28d组,通过茜素红染色、碱性磷酸酶（ALP）活性测定、矿化相关因子ALP、Ⅰ型胶原（COLⅠ）及成牙本质细胞标志因子牙本质涎磷蛋白（DSPP）mRNA的表达证实hDPCs成牙本质细胞向分化并成功建立体外矿化模型,用实时荧光定量PCR（qPCR）方法检测矿化诱导过程中细胞内HtrA1、TGF-β1和Smad3mRNA的表达情况。结果：矿化诱导后,与对照组比较,矿化结节产生逐渐增多,hDPCs细胞内ALP活性增强（P〈0.05）。qPCR结果显示,诱导后细胞的ALP、COLⅠ及DSPP mRNA表达水平增高（均P〈0.05）。各时间点HtrA1和TGF-β1mRNA的表达均高于0d组（均P〈0.05）,Smad3mRNA的表达有下降趋势,但差异无统计学意义（P〉0.05）。结论：HtrA1、TGF-β1可能共同参与hDPCs向成牙本质细胞样细胞分化的过程,Smad3在这一过程中扮演的角色仍需要进一步的研究。

英文摘要：

Objective：The purpose of the present study was to investigate the expressions of HtrA1, TGF-β1 and Smad3 during the odontoblastic differentiation of human dental pulp cells （hDPCs）. Methods. hDPCs were cultured in mineralization medium for 28 days. Mineralized nodules formation, alkaline phosphates （ALPase） activity and the expressions of the mineralization-related genes including ALP, collagen type I and dentin sialophosphoprotein （DSPP） were evaluated to determine the odontoblastic differentiation. Simultaneously, the expressions of HtrA1, TGF-β1 and Smad3 also were detected by qPCR. Results. Mineralized nodules formation, ALPase activity and the expressions of mineraliazation-related genes progressively increased in the process of odontoblastic differentiation of hDPCs. Meanwhile, the expressions of HtrA1 and TGF-β1 mRNA also increased significantly （ P 〈0.05）, while the expression of Smad3 showed no significant difference in this procedure （P 〉0. 05）. Conclusion： HtrA1 and TGF-β1 were involved in the process of odontoblastic differentiation of hDPCs and the role of smad3 during odontoblastic differentiation need to be further confirmed.