摘要
目的:观察具有矿化活性的人牙髓干细胞(human dental pulp stem cell,HDPSC)在重组人转录生长因子β1(transforming growth factor-β1,TGF-β1)作用下对牙本质基质蛋白1(dentin matrix protein1,Dmp1)表达和Dmp1基因启动子转录活性的影响。方法:通过建立体外培养的HDPSC矿化诱导模型,经10ng/L重组人TGF-β1刺激后,运用RT-PCR、报告基因检测等方法检测细胞在TGF-β1作用后Dmp1mRNA表达变化以及对pGL3-P-193～+86和pGL3-P-505～+862个启动子片段重组报告基因载体活性的影响。结果:诱导矿化后具有部分成牙本质细胞样细胞特征的HDPSC经TGF-β1刺激后,Dmp1mRNA的表达水平明显下降,并存在时间依赖性。pGL3-P-193～+86和pGL3-P-505～+86相对荧光素酶活性均下降,以pGL3-P-505～+86活性下降更明显,说明TGF-β1具有下调HDPSCDmp1转录活性的作用。计算机分析结果发现,Dmp1基因启动子-505～+86bp区存在多个TGF-β1下游作用分子Smads的结合位点。结论:TGF-β1可下调Dmp1mRNA的表达水平和转录活性,以pGL3-P-505～+86活性下降更明显。启动子-505～-193bp区存在TGF-β1下游作用分子或转录因子的结合位点,从而参与下调Dmp1转录表达过程。
Objective：To examine the roles of transforming growth factor-β1 （TGF-β1）on the expression of dentin matrix protein 1 Dmpl mRNA and the transcriptional activities of Dmp1 gene in induced human dental pulp stem cell（HDPSC）. Methods： The mineralized induction model of the HDPSC in vitro was established. The changes of Dmp1 mRNA and the transcription activities of two promoter construction, pGL3-P 193-＋86 and pGL3- P-505-＋86 were detected and analyzed after the cells were treated with 10 ng/L recombined human TGF-β1. Resalts-The results showed that the levels of Dmp1 mRNA were obviously decreased with time-dependence after the stimulus of TGF-β1. The transcription activities of pGL3-P193-191-＋86 and pGL3-P-505-＋86 decreased, especially in pGL3-P-505 -＋86 group. Computer analysis showed that the fundamental binding sites of downstream molecules or transcription factors existed in promoter region -505 - ＋ 86 bp of Dmp1 gene. Condusion：TGF-β1 can decrease the expression levels and transcriptional activities of Dmp1 gene, and it was presumed that Smads could mediate the process of down-regulation of Dmp1 gene by TGF-β1.
出处
《实用口腔医学杂志》
CAS
CSCD
北大核心
2007年第6期871-875,共5页
Journal of Practical Stomatology
基金
陕西省自然科学基础研究计划项目(编号:2005C221)
关键词
转录生长因子β1
牙本质基质蛋白1
人牙髓干细胞
报告基因
转录活性
Transforming growth factor-β1
Dental matrix protein 1
Human dental pulp stemcell
Report gene
Transcriptional activity
