TRAF3抑制NF-κB引起的肾囊腔形成作用

Effects of TRAF3 on inhibiting cyst formation induced by NF-κB signaling in kidney

目的:研究肿瘤坏死因子受体相关因子3(TRAF3)对多囊肾集合管上皮细胞中核因子κB(NF-κB)信号通路及其下游产物表达的影响;观察TRAF3基因过表达的多囊肾集合管上皮细胞形成管状分支结构的变化,探讨TRAF3在多囊肾囊腔形成的发生发展中可能产生的作用。方法:Western blot检测多囊肾集合管上皮细胞和TRAF3基因过表达多囊肾集合管上皮细胞中NF-κB信号通路的变化,同时检测下游凋亡因子Bax及Bid的表达及caspase-3活性变化;通过Annexin V-FITC/PI双染法检测各组细胞的凋亡情况;应用三维(3D)培养法观察多囊肾集合管上皮细胞形成管状分支结构变化的差异。结果:TRAF3的过表达能显著抑制多囊肾集合管上皮细胞中NF-κB信号通路的活性,使下游的Bax及Bid表达显著下调,细胞凋亡明显减少;TRAF3基因过表达多囊肾集合管上皮细胞管状分支结构较多囊肾集合管上皮细胞组明显增多。结论:TRAF3可能通过调节NF-κB信号通路降低Bax及Bid活性,抑制细胞凋亡,从而抑制多囊肾囊腔形成。

AIM： To investigate the effects of tumor necrosis factor（ TNF） receptor associated factor 3（ TRAF3） on the signaling pathway of NF-κB and the expression of Bax and Bid in renal collecting duct epithelial cells of polycystic kidney disease（ PKD）,and to observe the tubulogenesis of TRAF3 transgenics for exploring the protective effect of TRAF3 on the cystogenesis and development of PKD. METHODS： The signaling changes of NF-κB and expression of Bax and Bid in PKD renal collecting duct epithelial cells and TRAF3 transgenic PKD renal collecting duct epithelial cells were determined by the Western blot. The percentage of apoptotic cells was measured by flow cytometry with Annexin V staining. The caspase-3 activity was also measured. The 3D Matrigel culture was performed to examine abnormal tubulomorphogenesis in vitro. RESULTS： The over-expression of TRAF3 significantly inhibited the signaling pathway of NF-κB in PKD renal collecting duct epithelial cells and significantly downregulated the expression of Bax and Bid,and also decreased the cell apoptosis. More branch structures were observed in the TRAF3 transgenic PKD renal collecting duct epithelial cells. CONCLUSION： TRAF3 is a negative regulatory inhibitor for Bax and Bid by regulating the NF-κB signaling and may be a new target for inhibiting the cyst formation in PKD.