Figure 2.

Corticosteroids may regulate gene expression in several ways. Corticosteroids enter the cell to bind to GR in the cytoplasm that translocate to the nucleus. GR homodimers bind to GRE in the promoter region of steroid-sensitive genes, which may encode anti-inflammatory proteins. Less commonly, GR homodimers interact with negative GREs to suppress genes, particularly those linked to side effects of corticosteroids. Nuclear GR also interact with coactivator molecules, such as CBP, which is activated by proinflammatory transcription factors, such as NF-κB, thus switching off the inflammatory genes that are activated by these transcription factors. Other abbreviations: SLPI: secretory leukoprotease inhibitor; MKP-1: mitogen-activated kinase phosphatase-1; IκB-α: inhibitor of NF-κB; GILZ: glucocorticoid-induced leucine zipper protein; POMC: proopiomelanocortin; CRF: corticotrophin-releasing factor.