TGF-β3作用下人牙髓细胞内Smad2、Smad3蛋白表达水平的变化

In vitro effect of TGF-β 3 on Smad 2 or 3 protein expression in human dental pulp cells

目的:探讨TGF-β3对人牙髓细胞内Smad2、Smad3蛋白表达的调控作用和差异。方法:取生长良好的第5代人牙髓细胞,分为实验组和对照组,实验组用5ng/mLTGF-β3刺激并培养6、12、24、48h,对照组不予刺激。提取各组总蛋白质,分别用Smad2、Smad3抗体进行Western印迹杂交。结果:与对照组相比,Smad3在TGF-β3刺激后6h、12h,其蛋白表达量无明显变化,而在刺激后24h表达量明显下降,刺激48h后表达十分微弱;Smad2在对照组以及刺激后各时间组,其蛋白表达量无显著变化。结论:人牙髓细胞内存在Smad2、Smad3蛋白的表达,TGF-β3对二者表达的调控方式有所不同,刺激后期Smad3表达水平的下调可能与TGF-β3负反馈调节自身的信号有关。

AIM：To explore the in vitro effect of TGF - β3 on Smad 2/3 protein expression in human dental pulp cells and compare the difference. METHODS： Human dental pulp cells at passage 5 were divided into experimental and control groups. Cells in experimental group were incubated with 5ng/ml TGF - β 3 for 6 h, 12 h, 24 h and 48 h. Total protein was isolated from cells in each group respectively and the modulation of Smad 2 or 3 protein expression by TGF - β 3 was evaluated with Western blot analysis. RESULTS：The expression of Smad 3 was unchanged within 6 h and 12 h after TGF - 3 treatment, but it decreased markedly after 24 h and kept dropping by 48h. In contrast, the protein expression of Smad 2 remained stable after TGF - β3 treatment. CONCLUSION：The in vitro effect of TGF - β 3 on Smad 2 or 3 protein expression in human dental pulp cells is different. Down - regulation of Smad 3 expression later in TGF - β 3 treatment is involved in negative modulation of TGF - β3 signaling.