摘要
目的研究Smad7在成牙本质细胞系MDPC23内转化生长因子(transforminggrowthfactorβ1,TGFβ)信号转导的作用。方法培养MDPC23细胞,免疫组化法观察TGFβ1对MDPC23细胞内Smad7分子定位改变。通过瞬时共转染和报告基因检测方法观察Smad7分子对TGFβ1调控目的基因转录的影响。结果MDPC23细胞表达Smad7蛋白,主要定位于细胞胞浆,在转化生长因子β1刺激30min后,Smad7从胞核向胞浆转位聚集。TGFβ1显著诱导p3TP Lux基础启动子活性。过表达Smad7完全抑制TGFβ1对p3TP Lux启动子活性的诱导,而过表达Smad7反义cDNA载体则显著促进了TGFβ1对p3TP Lux启动子活性的诱导。结论在成牙本质细胞系MDPC23内,Smad7可能作为一种抑制性Smad分子在拮抗TGFβ1信号转导过程中发挥重要的作用。
Objective To investigate the role of Smad7 in TGF-β1 signaling in odontoblast cell line MDPC-23.Methods MDPC-23 cells were cultured in a-MEM with 10% fetal bovine serum (FBS). The change of intracellular location of Smad proteins treated by TGF-β1 was evaluated immunohistochemically. The effects of Smad7 on TGF-β1-induced transcriptional activity were investigated in cotransfection experiments using TGF-β-responsive p3TP-Lux reporter.Results MDPC-23 cells expressed Smad7 protein. Endogenous Smad7 rapidly translocated from the nucleus into the cytoplasm after treatment by TGF-β1 for 30 min. The activity of TGF-β-responsive p3TP-Lux reporter was significantly induced by TGF-β1. Overexpression of Smad7 completely abrogated stimulation of p3TP-Lux activity by TGF-β1,whereas overexpression of Smad7 antisense cDNA markedly promoted TGF-β1-induced luciferase activity.Conclusion These findings suggest that Smad7 is an antagonistic Smad which may serve as a negative regulator of TGF-β1 in MDPC-23 cells.
出处
《北京口腔医学》
CAS
2005年第2期76-78,共3页
Beijing Journal of Stomatology
基金
国家自然科学基金资助项目(30200315)
