摘要
目的研究Smads蛋白在成牙本质细胞系MDPC-23作为转化生长因子(TGF)β信号分子的作用。方法常规条件下培养MDPC-23细胞,在TGF-β1刺激培养1h后,观察细胞内Smad分子的定位变化。将Smads真核表达载体分别与报告基因载体p3TP-Lux瞬时共转染至MDPC-23,在TGF-β1刺激培养24h后,裂解细胞,用双荧光素酶报告基因检测系统检测细胞裂解液中的荧光素酶活性。结果MDPC-23细胞表达Smad2和Smad3蛋白分子,主要定位于细胞质,在TGF-β1刺激1h后,Smad2和Smad3从胞质向胞核转位聚集。TGF-β1可诱导p3TP-Lux基础启动子活性,约增加13倍。过表达野生型Smad3蛋白可促进TGF-β1对p3TP-Lux启动子活性的诱导,但是过表达Smad3突变体抑制TGF-β1对p3TP-Lux启动子活性的诱导。和Smad3作用相比,过表达Smad2野生型或突变型蛋白对TGF-β1诱导p3TP-Lux启动子活性无明显影响。结论在成牙本质细胞系MDPC-23内,Smad信号途径存在并参与介导TGF-β1诱导的转录调控。
Objective To investigate the role of Smad proteins as mediators of TGF-β in odontoblast cell line MDPC-23. Methods We performed cell culture, immtmocytochemistry, transient transfection and lueiferase assay. Results MDPC-23 cells expressed Smad2 and Smad3 which were proteins. Endogenous Smad2 and Smad3 were rapidly translocated from cytoplasm into the nucleus after the treatment by TGF-β1 for 1 h. The activity of TGF-β responsive p3TP-Lux reporter construct was stimulated by 13 folds by TGF-β1 treatment. Overexpression of wild-type Smad3 promoted TGF-β1 to induce lueiferase activity, whereas dominant negative Smad3 inhibited it, In contrast to Smad3, the transfection of Smad2 and/or its dominant negative mutant had minimal effects on TGF-β1 which induced transcriptional activity of p3TP-Lux, Conclusion The Smad pathway is functional and involved in transcriptional regulation induced by TGF-β1 in odontoblast cell line MDPC-23.
出处
《口腔医学》
CAS
2005年第4期193-195,共3页
Stomatology
基金
国家自然科学基金资助项目(30200315)
