222 Effects of itraconazole and tacrolimus on Aryl hydrocarbon receptor and NADPH quinine oxidoreductase 1

Background: Aryl hydrocarbon receptor (AhR) is a ligand-inducible transcription factor responding to halogenated aromatic hydrocarbons. AhR regulates nuclear factor-erythroid 2- related factor-2 (Nrf2), a key molecule for cell protection. Itraconazole (ICZ) and tacrolimus exhibit anti-inflammatory effects, but underlying molecular mechanism remains unclear, especially on AhR-Nrf2 pathway. Objectives: To evaluate the influence of ICZ and tacrolimus on AhR pathway, especially AhR-Nrf2 pathway. Methods: Normal human epidermal keratinocytes (NHEK) were treated with 2,3,7,8-tetrachlrodibenzo-p-dioxin TCDD), 6-Formylindolo[3,2-b]carbazole (FICZ), Indirubin, ICZ and tacrolimus. Then, RT-PCR and Western blot analysis were performed. Results: The expression levels of the AhR, Arylhydrocarbon receptor nuclear translocator (ARNT), Cytochrome P450 1A1 (CYP1A1) and NADPH quinine oxidoreductase 1 (NQO1) mRNA were higher when treated with TCDD, FICZ, and Indirubin, especially in 12 hours. However, with ICZ and tacrolimus, there was no significant difference from control. When analyzing protein expressions of NHEKs with Western blot, the levels of AhR, CYP1A1, and NQO1 were higher after treatment with TCDD, FICZ, and Indirubin. With ICZ and tacrolilmus, there was no significant difference Conclusion: ICZ and tacrolimus did not effect on mRNA and protein levels of AhR-related factors. This suggests ICZ and tacrolimus exhibit different pathway from AhR.