TGF-β/Smad信号通路对肾小球系膜细胞COX-2表达的影响

Effect of TGF-β/Smad signaling pathway on the expression of COX-2 in mesangial cells

目的探讨转化生长因子β(TGF-β)/Smad信号通路对肾小球系膜细胞环氧化酶2(COX-2)表达的影响。方法取传代培养第4代系膜细胞进行分组:对照组(A组)、TGF-β5 ng/ml组(B组)、TGF-β10 ng/ml组(C组)、TGF-β10 ng/ml+NS-398 10μmol(D组)和TGF-β10 ng/ml+staurosporine 5 nmol/ml组(E组)。用RT-PCR方法测定各组COX-2 mRNA及Smad 2 mRNA的表达,Western blot法测定各组COX-2及Smad 2蛋白的表达。结果不同浓度TGF-β作用4、12、24 h后,系膜细胞Smad 2 mRNA和COX-2 mRNA表达及二者的蛋白表达均增加,且呈浓度和时间依赖性(P<0.05),加入COX-2抑制剂NS-398或Smad 2抑制剂staurosporine后,COX-2和Smad 2的表达均减少(P<0.05)。COX-2和Smad 2表达呈正相关(r=0.9438,P<0.05)。结论 TGF-β可通过Smad信号通路刺激肾小球系膜细胞COX-2的表达。

Objective：To investigate the effect of transforming growth factor-β（TGF-β）/Smad signaling pathway on the expression of cyclooxygenase-2（COX-2） in rat mesangial cells.Methods：The fourth generation of glomerular mesangial cells were randomly divided into 5 groups of A（without treatment as the control）,B（treated with TGF-β 5 ng/ml）,C（treated with TGF-β 10 ng/ml）,D（treated with TGF-β 10 ng/ml plus NS-398 10 μmol） and E（treated with TGF-β 10 ng/ml plus staurosporine 5 nmol/ml）.The expressions of COX-2 mRNA and Smad 2 mRNA were determined by RT-PCR.The protein expressions of COX-2 and Smad 2 were analyzed by Western blot.Results：After TGF-β stimulation for 4,12 and 24 h,both the mRNA and protein expressions of Smad 2 and COX-2 were increased in concentration-and time-dependent manner（P0.05）,which were significantly inhibited when pretreated with NS-398（COX-2 inhibitor） or staurosporine（Smad 2 inhibitor）,respectively（P0.05）.There was a positive correlation between COX-2 and Smad 2（r=0.9438,P0.05）.Conclusion：TGF-β might promote COX-2 expression in mesangial cells via Smad signaling pathway.