Dexamethasone is a member of the glucocorticoid group of steroid hormones; it functions as an anti-inflammatory and immunosuppressant. A differentially- expressed transcript of unknown function has been identified in emphysematous lungs []- this has been named Dexamethasone-Induced transcript (DEXI). It is suggested that the up-regulation of DEXI in emphysema patient's tissues may be a direct result of their treatment with corticosteroids.The human DEXI protein is a 95-residue acidic polypeptide, predicted to contain a central transmembrane domain and a C-terminal leucine zipper []. It is unclear how dexamethasone influences proteins within this family. However, the leucine zipper contains a predicted casein kinase II phosphorylation site, suggesting that interaction may possibly be regulated by phosphorylation. It is hoped that further studies will eventually help to elucidate the function of this protein and its role in emphysema and inflammatory-airway disease.
