Effects of 2-acetylaminofluorene on the interleukin-1βgene expression in macrophages

Abstract

The effects of 2-acetylaminofluorene (AAF), an arylamide carcinogen, on IL-1 production and IL-1 gene expression were investigated. AAF inhibited IL-1 production in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells and rat peritonial macrophages. To further characterize the effect of AAF on the gene expression of IL-1β, we assessed the effect of AAF on the expression of IL-1β mRNA using competitive RT-PCR. Treatment of RAW 264.7 cells and mouse splenic macrophages with AAF significantly inhibited the production of IL-1β mRNA. In order to investigate the effects of AAF on the regulation of IL-1β gene expression, the effects of AAF on the activation of transcription factors such as NF-κB, AP-1, CRE, and NF-IL6 were examined using a transient transfection and chloramphenicol acetyltransferase (CAT) assay and electrophoretic mobility shift assay. AAF inhibited the transcriptional activation of NF-κB in LPS-stimulated RAW 264.7 cells. The DNA binding activity of NF-κB was also inhibited by AAF in LPS-stimulated RAW 264.7 cells. These data suggest that inhibition of IL-1β gene expression by AAF is mediated by blocking LPS-stimulated NF-κB activation.