Objective   To investigate the expression of glucocorticoid receptor (GR) α and β in cultured human keratinocytes (HaCaT cells) with treatment of dexamethasone (Dex) and after withdrawal.   Methods   The mRNA and protein expressions of GRα and GRβ in HaCaT cells after the treatment of Dex (10

-6

mol/L) for 24 and 48 h and in 24

48 and 72 h after withdrawal of Dex were detected by real-time PCR and Western blot analysis respectively. The intracellular distribution of GRα and β was examined by immunofluorescence.   Results   In 24 or 48 h after Dex treatment

the expressions of GRα at mRNA and protein levels were reduced in a time-dependent manner (P0.05)

and those of GRβ were increased (P0.05) as shown by real-time PCR and Western blot analysis. However

in 24

48 and 72 h after withdrawal of Dex

the above changes gra-dually recovered to their previous levels.   Conclusion   Dex down-regulates GRα but up-regulates GRβ

which may partly explain that the tachyphylaxisis correlated to persistent application of topical glucocorticoids. After Dex is removed

both GRα and GRβ could recover to their previous levels

suggesting long-term application of topical glucocorticoid should be avoided.