Mutant glucocorticoid receptor binding elements on Interleukin-6 promoter regulate dexamethasone effects

Glucocorticoid has been widely used as an important modulator for clinical infectious and inflammatory disease. Glucocorticoid receptor (GR) is a transcription factor belonging to the family of nuclear receptors, regulated anti-inflammatory process and the release of pro-inflammatory cytokines. Five putative GR and other transcription factor binding sites on interleukin (IL)-6 promoter were identified and dexamethasone could reduce LPS-induced IL-6 release. Among them, the mutant transcriptional factors NF-{kappa}B, AP-1, and Sp1-2 site decreased the basal and effects of lipopolysaccharide (LPS)-induced IL-6 promoter activities in different responses. GR2/3 seemed to be an important role in both basal and inducible promoter activities in LPS-induced inflammation. We concluded that the selective GR2/3 modulators may have agonistic and antagonistic combined effects and activate important signaling pathway during LPS-stimulated inflammatory process.