SMAD公司
牙本质涎磷蛋白
成牙本质细胞
荧光素酶
细胞生物学
分子生物学
报告基因
转化生长因子
转化生长因子β
化学
转录因子
生物
细胞培养
转染
基因表达
基因
牙本质
生物化学
医学
遗传学
牙科
作者
He Wang,Ziru Niu,Suping Zhao,Weilin Jin,Jie Gao,Anthony J. Smith
标识
DOI:10.1016/j.archoralbio.2004.05.005
摘要
Transforming growth factor-beta (TGF-beta) regulates odontoblast differentiation and stimulates dentine extracellular matrix synthesis. However, until recently, the molecular mechanisms of action of TGF-beta have been unknown. Smad proteins have recently been identified as intracellular signalling mediators of TGF-beta. In this study, we characterise the role of Smad proteins as mediators of TGF-beta in a mouse odontoblast cell line MDPC-23.Transcription of Smads was detected by RT-PCR. The change of intracellular location of Smad proteins treated by TGF-beta1 was evaluated immunocytochemically. Smad function and its role in transcription of dentin sialophosphoprotein (DSPP) were investigated in cotransfection experiments using promoter-luciferase reporter gene constructs.MDPC-23 cells expressed Smad2, Smad3 and Smad4 mRNA. Endogenous Smad2, Smad3 and Smad4 rapidly translocated from the cytoplasm into the nucleus in response to TGF-beta1. The activity of the TGF-beta-responsive p3TP-Lux reporter construct was stimulated by 12.7-fold with TGF-beta1 treatment. Over-expression of wild-type Smad3 promoted TGF-beta1-induced luciferase activity, whereas dominant negative Smad3 inhibited it. TGF-beta1 also inhibited the activity of DSPP promoter luciferase reporter construct containing the sequence between -791 bp and +54 bp of the mouse DSPP gene. Over-expression of wild-type Smad3 potentiate the inhibitory effect of TGF-beta1 on transcriptional regulation of DSPP, while dominant negative Smad3 decreased the effect. In contrast to Smad3, wild-type Smad2 or its dominant negative mutant had little effect on TGF-beta1 regulation of the promoter activity of DSPP.Smad2, Smad3 and Smad4 are present and activated by TGF-beta1 in MDPC-23 cells. The Smad pathway is functional in these cells and Smad3 appears to be involved in down-regulation of DSPP by TGF-beta1. These findings raise the possibility that Smad signalling plays a role in dentinogenesis.
科研通智能强力驱动
Strongly Powered by AbleSci AI