Interleukin‐1 ‐induced expression of nitric oxide synthase in insulin‐producing cells is preceded by c‐fos induction and depends on gene transcription and protein synthesis

Abstract

The cytokine interleukin 1β (IL‐1β) induces the expression of an isoform of nitric oxide synthase (NOS) in insulin‐producing cells which is similar to that expressed in activated macrophages. In the present study we show that IL‐1β‐induced expression of NOS mRNA in these cells is preceded by expression of c‐fos mRNA. Moreover, the stimulatory effects of recombinant IL‐1β on NOS mRNA expression are prevented by co‐incubation with an inhibitor of gene transcription (actinomycin D) or an inhibitor of protein synthesis cycloheximide). These data suggest that IL‐1β‐induced NOS mRNA expression may be mediated by transcription of immediate early response genes, and that c‐fos may be one of these genes.