外源性转化生长因子β_1与小鼠肝细胞Smad7 mRNA及蛋白表达的关系

Influence of TGF β_1 on expression of Smad7 mRNA and protein in rat liver cells

目的 探讨外源性转化生长因子 β1(TGFβ1)对鼠肝细胞株BRL细胞生长及其胞内信号传导抑制Smad7蛋白和mRNA表达的影响。方法 按照细胞与TGFβ1共同孵育的时间将实验分为TGFβ刺激 0min组、90min组和 2 4h组 ;用逆转录 聚合酶链反应 (RT PCR)、Westernblot和免疫组化技术分别检测Smad7mRNA、蛋白的表达及其在细胞中的定位。结果 TGFβ1刺激 0min组、90min组 ,2 4h组的鼠肝细胞生长和形态学变化差异无显著意义 ;然而 ,3组间的Smad7mRNA和蛋白质表达水平存在明显差异 ,90min组强于 2 4h组 ,2 4h组又强于 0min组 ;Smad7免疫反应阳性信号主要在细胞浆。结论 TGFβ1在 90min至 2 4h内无诱导BRL细胞生长停滞作用 。

Objective To investigate the influence of exogenous transforming growth factor beta 1 (TGFβ1) on growth and signal inhibitor Smad7 protein and its mRNA in BRL cells (rat liver cell line). Methods BRL cells were incubated with TGFβ1 and divided into 0 minute group, 90 minute group and 24 hour group according to the time of incubation with TGFβ1. Morphologic changes were observed. The expression of Smad7 mRNA and protein was investigated by reverse transcriptase polymerase chain reaction (RT PCR), Western blotting, and immnuohistrochemistry. Results Growth stagnancy and morphologic change of cells was not seen among the three groups. The expression levels of Smad7 mRNA was the highest in 90 minute group and the lowest in 0 minute group, and the 24 hour group took the second place. Most of the Smad7 immune positive granules were observed in cytoplasm. Conclusion TGFβ1 does not induce growth stagnancy in BRL cells during the period of 90 minutes to 24 hours. There is a relation of effectiveness for a given period of time between the level of Smad7 and TGFβ1 stimulation.