The molecular mechanism of the stimulation of adipocyte differentiation by a glucocorticoid

The glucocorticoid dexamethasone (dex) stimulates differentiation of cultured preadipocytes of the 3T3-L1 cell line to adipocytes. The preadipocytes express a gene termed preadipocyte factor 1 (pref-1). The pref-1 gene product is abundant in preadipocytes but completely absent in adipocytes. Constitutive expression of pref-1 blocks differentiation of adipocytes, as does a soluble 50 kDa fragment of the pref-1 protein. It appears that dex mediates adipogenesis by down-regulating expression of pref-1.