Expression of transcription factor zinc-binding protein-89 (ZBP-89) is inhibited by inflammatory cytokines

Zinc-binding protein-89 (ZBP-89; ZNF148, BERF-1, BFCOL-1) is a zinc-finger transcription factor of the Kruppel family. It has been shown to regulate the expression of a number of genes, acting as either an activator or repressor of gene expression, depending on the context. It is over-expressed in several cancers, but has been shown to be involved in apoptosis and to have a negative influence on cell growth in part by interactions with p53. Previously, ZBP-89 was shown to activate transcription of the matrix metalloproteinase-3 (MMP-3) gene by binding to a polymorphic promoter element in competition with nuclear factor kappaB (NF-kappaB). NF-kappaB is known to be a key regulator of the inflammatory response, but relatively little is known about regulation of ZBP-89. In order to ascertain whether ZBP-89 is regulated during inflammation, we designed experiments to determine whether and to what extent ZBP-89 levels are affected by inflammatory cytokines. Here we show that ZBP-89 mRNA and protein expression are significantly inhibited in human fibroblasts by the inflammatory cytokine interleukin-1beta. Since any change in the levels of ZBP-89 would presumably impact the regulation of MMP-3 and other ZBP-89 target genes, these results provide important insight into mechanisms involved in fine-tuning the immune response.