TRAF3 delays cyst formation induced by NF-κB signaling

This study aims to investigate the effects of TNF receptors associated factor 3 (TRAF3) on the signaling pathway and expression of downstream products of nuclear factor kappa B (NF-κB) in the epithelial cells of renal ducts in individuals with polycystic kidney disease (PKD). We observe the TRAF3 genic overexpression of the epithelial cells, which form a tubular branch structure, in polycystic kidneys and to explore the protective effect of TRAF3 on the cystogenesis and progression of PKD. Western blotting analysis was conducted to examine the signaling changes of NF-κB in PKD the epithelial cells and TRAF3 transgenic PKD epithelial cells. Changes in the downstream apoptosis factor and cell proliferation in PKD epithelial cells and TRAF3 transgenic PKD epithelial cells were detected. A three-dimensional matrigel culture experiment was performed to examine abnormal tubulomorphogenesis in vitro. The overexpression of TRAF3 significantly inhibited the signaling pathway of NF-κB in the PKD epithelial cells, downregulated the expression of downstream factors Bcl-2 and Bcl-xl, and significantly decreased cystic epithelial cell proliferation. Additional branch structures were observed in the PKD epithelial cells with a three-dimensional culture compared to wildtype cells. TRAF3 may likely induce apoptosis and resistance to proliferation and may be a new target to inhibit the cyst formation in PKD by regulating the NF-κB signaling pathway Bcl-2 and Bcl-xl activity. © 2017 IUBMB Life, 69(3):170-178, 2017.