Fig. 2. Silent mating type information regulation 2 homolog (SIRT1) inhibition blocks Acrp30-induced filaggrin (FLG) upregulation. Human normal epidermal keratinocytes were pretreated with 60 µM sirtinol for 4 h, after which they were treated with 10 µg/ml Acrp30 for 12 h (A) or 24 h (B). Cell lysates were generated with described lysis buffer and analyzed by immunoblotting. The protein amounts were quantified by comparison to β-actin. Immunoblotting was used to analyze the levels of SIRT1, aryl hydrocarbon receptor nuclear translocator (ARNT), and FLG. All blots shown are representative of 3 independent experiments. ^***p<0.001 compared to the untreated group, ^****p<0.0005 compared to the untreated group. NT: no treatment, ST: sirtinol.