c-Jun、c-Fos对人牙本质基质蛋白1基因转录调控作用的研究

The effects of c-Jun and c-Fos on transcriptional activities of human dentin matrix protein 1 gene

目的观察c-Jun和c-Fos对人牙髓干细胞(human dental pulp stem cells,HDPSCs)牙本质基质蛋白1(dentin matrix protein 1,DMP1)基因转录活性的影响。方法将pRSV-c-Jun和pRSV-c-Fos瞬时转染至HDPSCs中,检测转染后不同时间c-Jun、c-Fos蛋白的表达变化。将重组报告基因载体pGL3-P-505～+86与pRSV-c-Jun、pRSV-c-Fos分别共转染至细胞中,报告基因检测系统检测荧光素酶活性变化。结果瞬时转染c-Jun、c-Fos后,蛋白主要表达于HDPSCs细胞胞浆中,并且在转染48h后表达量均达到最高值;c-Jun和c-Fos能够降低pGL3-P-505～+86的荧光素酶活性,c-Jun降低DMP1启动子区-505～+86bp片段的荧光素酶活性更为显著(P<0.05)。结论 c-Jun和c-Fos可降低人DMP1基因转录活性,是HDPSCs向成牙本质细胞方向分化重要的调节因子,DMP1基因启动子序列-110～-100bp区可能是c-Jun、c-Fos有效作用位点。

Objective To investigate the roles of c-Jun and c-Fos on the transcriptional activities of human dentin matrix protein 1（DMP1） gene in induced human dental pulp stem cells（HDPSCs）.Methods The expression of c-Jun and c-Fos protein was detected after the transient transfection of pRSV-c-Jun and pRSV-c-Fos into HDPSCs.The changes of DMP1 gene transcriptional activities were investigated and analyzed after the cotransfection of promoter construction pGL3-P-505～＋86 with pRSV-c-Jun and pRSV-c-Fos respectively into the cells.Results It was found that c-Jun and c-Fos were predominantly expressed in the cytoplasm of the HDPSCs and the expression reached to the maximum after transfection for 48h.Furthermore,forced overexpression of c-Jun and c-Fos induced the decreases of the luciferase activities of pGL3-P-505～＋86,especially those of c-Jun group were the most significant（P0.05）.Conclusion c-Jun and c-Fos can decrease the transcriptional activities of DMP1 gene,and they are the important regulatory factors during odontoblasts differentiation.The c-Jun and c-Fos binding site was probably found in promoter region from nt-110 to-100 of DMP1 gene combined with the results of computer analysis.