钙黏蛋白在地塞米松诱导的人牙髓细胞成牙本质向分化中的表达研究

摘要

目的：探讨钙黏蛋白（cadherins）在地塞米松诱导的人牙髓细胞（HDPCs）成牙本质向分化过程中的作用。方法：酶消化法分离培养 HDPCs，RT－PCR 检测 N－cadherin、OB－cadherin、R－cadherin 在 HDPCs 中的表达；采用10－7 mol／L 地塞米松对第3代 HDPCs 进行处理，实时定量聚合酶链式反应（qRT－PCR）检测成牙本质相关基因碱性磷酸酶（ALP）、牙本质基质蛋白－1（DMP －1）、牙本质涎磷蛋白（DSPP）和 N －cadherin、OB－cadherin、R－cadherin 表达水平的变化；茜素红染色观察矿化结节形成情况。结果：N－cadherin、OB－cadher-in、R－cadherin 均表达于 HDPCs。地塞米松显著上调 ALP、DMP－1、DSPP、R－cadherin 的表达水平，同时显著下调N－cadherin、OB －cadherin，矿化结节形成情况则无明显差异。结论：地塞米松可诱导 HDPCs 向成牙本质细胞分化，同时调节钙黏蛋白的表达，提示钙黏蛋白可能参与调控地塞米松对 HDPCs 成牙本质向分化的诱导过程。%AIM :To investigate the effects of cadherins on dexamethasone -induced odontoblastic differ-entiation of human dental pulp cells (HDPCs).METHODS:HDPCs were enzymatically separated from pulp tissues and cultured.The mRNA expression of N-cadherin,OB-cadherin and R -cadherin in HDPCs was determined by RT-PCR.The third passage of HDPCs were cultured in medium containing 10 -7 mol/L dexamethasone for 7 and 14 days respectively,and then qRT-PCR was performed to detect the expression changes of odontogenic -related genes,inclu-ding alkaline phosphatase (ALP),dentin matrix protein (DMP -1),dentin sialophosphoprotein (DSPP)and cadher-ins (N-cadherin,OB -cadherin and R -cadherin).The formation of mineralized nodules was assessed using alizarin red staining at day 14.RESULTS:The mRNA of N-cadherin,OB-cadherin and R -cadherin was expressed in HD-PCs cultured in vitro.HDPCs grown in dexamethasone -containing medium showed a significant upregulation of ALP, DMP -1,R -cadherin and DSPP mRNA both at day 7 and 14,while the formation of mineralized nodules showed no difference.Meanwhile,the expression levels of N -cadherin and OB-cadherin were decreased.CONCLUSION:Dexamethasone can induce odontoblastic differentiation of HDPCs and modulate the expression of cadherins during this procedure,indicating that cadherins may play an important role in dexamethasone -induced odontoblastic differentia-tion of HDPCs.