Dexamethasone Induced Protein (DEXI)

DEXI messenger RNA (mRNA) was upregulated 147% in emphysematous tissue compared with donor tissue. DEXI mRNA was also upregulated 230% by dexamethasone treatment of A549. The increase in expression of DEXI found in emphysema patients' tissues may be owing to their known treatment with corticosteroids. The human DEXI gene is intronless and the predicted open reading frame encodes a 95-residue acidic protein. Database searches revealed the presence of homologues only in mammals, and a human pseudogene. The protein has a predicted central transmembrane domain and a carboxy-terminal leucine zipper. The human mRNA has a single 1.3-kb transcript. The increased expression of DEXI in emphysema may either be relevant to disease progression or be indicative of glucocorticoid responsiveness in treated patients.