Fig. 3. HDM or C48/80 induces the upregulation of KLK5 and PAR2 as well as NFκB activation via reactive oxygen species. (A) Normal human epidermal keratinocytes (NHEKs) were treated with HDM (10 mg/ml; left panel) or C48/80 (10 µg/ml; right panel) in the absence (−) or presence (+) of NAC for 1 hour, and cells were harvested for reverse transcriptase-polymerase chain reaction (RT-PCR) experiments of KLK5 and PAR2 as described in the Materials and Methods. The pictures demonstrate the typical results of three repetitive RT-PCR experiments for KLK5 and PAR2 in the HDM-treated NHEKs (left panel) and C48/80-treated NHEKs (right panel). (B) Relative mRNA expression levels were semi-quantified by densitometric analysis. HDM: house dust mites, NAC: N-acetyl cysteine, KLK5: kallikrein 5, PAR2: proteinase-activated receptor 2. ^*p<0.05.