This study demonstrates for the first time the effects of IL-1 beta on the regulation of protein production as well as MUC2 gene transcription in cultured human airway epithelial cells. The effect of IL-1 beta on the regulation of MUC2 protein was determined by flow cytometric analysis. The expression level of MUC2 induced by IL-1 beta increased in a dose-dependent manner. MUC2 transcripts were detected after 2 h of exposure to IL-1 beta and reached maximal level after 8 h. Actinomycin D experiments indicated that the IL-1 beta-mediated MUGS expression was controlled by transcriptional regulation. Both RT-PCR and FAGS analysis showed that budesonide concomitantly attenuated IL-1 beta mediated MUC2 gene as well as protein production levels. Use of the glucocorticoid receptor antagonist, RU-486, restored the inhibitory effect of budesonide on the IL-1 beta-mediated MUC2 protein as well as gene. The data suggest that IL-1 beta up-regulates MUC2 gene by transcriptional regulation and that budesonide suppresses the IL-1 beta-medicated MUGS expression via decreased transcriptional activation.