人牙髓细胞内Smad2、3在转化生长因子β_1信号转导中的作用  

The roles of Smad 2/3 in transforming growth factor-β_1 signaling in human dental pulp cells

作　　者：包柳郁[1] 汪平[1] 牛忠英[2] 

机构地区：[1]第四军医大学口腔医学院牙体病科,西安710032 [2]解放军第306医院口腔科

出　　处：《中华口腔医学杂志》2003年第1期39-42,I003,共5页Chinese Journal of Stomatology

基　　金：国家自然科学基金资助项目 ( 39870 789)

摘　　要：目的　探讨人牙髓细胞内Smad 2、3在转化生长因子 β1 (transforminggrowthfactor β1 ,TGF β1 )信号转导过程中的作用。方法　原代培养人牙髓细胞 ,用激光共聚焦显微镜观察TGF β1 刺激初期牙髓细胞内Smad 2、3由胞质向胞核转位的现象 ,同时采用Westernblot方法检测刺激后期Smad 2、3蛋白表达的变化。结果　TGF β1 刺激 2h内 ,Smad 2、3在胞质中表达渐弱 ,在胞核内表达渐强 ,呈现由胞质向胞核逐步转位的趋势。Smad 2蛋白总量在TGF β1 刺激前后几乎无变化 ,而Smad 3在刺激后 2 4h表达量明显下降 ,48h后表达十分微弱。结论　Smad 2、3可能是人牙髓细胞内TGF β1 的信号转导分子。TGF β1 刺激初期Smad 2、3通过发生转位参与转导TGF β1 信号至核内 ,刺激后期Smad 3表达水平的下调可能与TGF β1Objective To explore the roles of Smad 2/3 in transforming growth factor β 1(TGF β 1) signaling by human dental pulp cells Methods Laser scanning confocal microscope was used to observe translocation of Smad 2/3 from plasma into nucleus in cultured dental pulp cells at early stage of TGF β 1 treatment, and changes of Smad 2/3 protein expression at later stage were evaluated by Western blot analyses Results The expression of Smad 2/3 (fluorescence intensity)kept decreasing in cytoplasm but increasing in nucleus within 2 h after TGF β 1 treatment, forming a trend that Smad 2/3 translocated into nucleus from cytoplasma The total amount of Smad 2 protein remained unchanged before and after TGF β 1 treatment, but the expression level of Smad 3 decreased markedly after 24 h treatment and kept droping by 48 h Conclusions The results suggest that the Smad 2/3 may be the downstream signal transducers of TGF β 1 in human dental pulp cells and Smad 2/3 may mediate TGF β 1 signaling by translocation early in TGF β 1 treatment, while down regulation of Smad 3 expression by TGF β 1 at later stage is involved in negative modulation of TGF β 1 signaling

关 键 词：牙髓细胞 SMAD2 SMAD3 转化生长因子β1 信号转导 光转录 

分 类 号：R780.2[医药卫生—口腔医学]