中文摘要：

目的：观察肿瘤坏死因子-α（TNF-α）对小鼠脑微血管内皮细胞RhoA活性和表达的影响,探讨p115RhoGEF是否参与其调控。方法：以小鼠脑微血管内皮细胞株bEnd.3为实验对象,TNF-α（10μg/L）刺激后pull-down检测RhoA活性,Western blotting检测RhoA总蛋白表达;再将bEnd.3分为siRNA组（转染p115RhoGEFsiRNA）和对照组（转染无活性的nsRNA）,Western blotting检测p115RhoGEF蛋白的表达,pull-down检测TNF-α预处理后RhoA活性的变化。结果：RhoA活性在TNF-α刺激30 min后明显增高达到高峰,RhoA总蛋白表达在TNF-α刺激12 h和24 h显著上调;TNF-α刺激siRNA组bEnd.3细胞30 min后,RhoA活性较对照组明显降低。结论：TNF-α可导致小鼠脑微血管内皮细胞RhoA活性增加和表达上调,p115RhoGEF可能参与了TNF-α诱导RhoA活化的调控过程。

英文摘要：

AIM：To investigate the effects of tumor necrosis factor α（TNF-α） on RhoA activity in mouse cerebral microvascular endothelial cells.METHODS： The bEnd.3 cells,a mouse brain microvascular endothelial cell line,were cultured.RhoA activity was analyzed by pull-down assay 10 min,30 min and 60 min after TNF-α treatment.Expression of RhoA protein was determined by Western blotting 1 h,3 h,6 h,12 h and 24 h after TNF-α treatment.Small interfering RNA（siRNA） targeting to p115RhoGEF or control nsRNA was transfected into bEnd.3 cells. The expression of p115RhoGEF was determined by Western blotting,and RhoA activity was detected by pull-down assay 30 min after TNF-α treatment.RESULTS： RhoA activity peaked at 30 min after TNF-α treatment（P0.01）.TNF-α significantly increased the protein expression of RhoA at 12 h and 24 h（P0.05）. Knock-down of p115RhoGEF by siRNA in bEnd.3 cells attenuated TNF-α-induced RhoA activation（P0.05）.CONCLUSION： TNF-α up-regulates RhoA activity and expression.p115RhoGEF may play a role in TNF-α-induced activation of RhoA.