Identification of TNF-α-responsive NF-κB p65-binding element in the distal promoter of the mouse serine protease inhibitor SerpinE2

Serine protease inhibitor SerpinE2 is known as a cytokine-inducible gene. Here, we investigated whether tumor necrosis factor α-(TNF-α)-induced expression of SerpinE2 is mediated by the nuclear factor-κB (NF-κB) p65 subunit. Both steady state and TNF-α-induced expression of SerpinE2 mRNA were abrogated in p65−/− murine embryonic fibroblasts (MEFs). Reconstitution with wild-type p65 rescued SerpinE2 mRNA expression in an IκB kinase β-dependent manner. Electrophoresis mobility shift assay and ChIP assay demonstrated that p65 bound to the κB-like DNA sequence located at approximately −9 kbp in the SerpinE2 promoter. In addition, TNF-α stimulated luciferase gene expression driven by the κB-like element in the reconstituted MEFs, but not in p65−/− MEFs. These results indicated that activation of NF-κB p65 plays an important role in TNF-α-induced expression of SerpinE2.