Figure 2

HMGB1 increases prostaglandin E synthase transcription in human dermal papilla cells (hDPCs). (a) mRNA expression of cyclooxygenase-1 (COX-1), cyclooxygenase-2 (COX-2), microsomal prostaglandin E synthase-1 (mPGES-1), microsomal prostaglandin E synthase-2 (mPGES-2), cytosolic prostaglandin E (cPGES), aldo-keto reductase family 1 member C1 (AKR1C1), aldo-keto reductase family 1 member C3 (AKR1C3), carbonyl reductase-1 (CBR-1), prostaglandin D synthase (PTGDS), alkaline phosphatase (ALPL), and vascular endothelial growth factor (VEGF) was examined in hDPCs treated with 100 or 200 ng/ml HMGB1 by real-time PCR analysis. The relative mRNA levels were normalized to GAPDH. The results are expressed as mean ± SD of three independent experiments. *p < 0.05 and **p < 0.01 compared to control group using ANOVA. (b) hDPCs were treated with 200 ng/ml HMGB1 for different incubation periods (0.5, 1, 2, and 4 h). The protein levels of COX-1, COX-2, mPGES-1, mPGES-2, and cPGES were measured using western blot analysis. β-actin served as a loading control. The results are expressed as mean ± SD of three independent experiments. *p < 0.05, **p < 0.01, and ***p < 0.001 compared with control group using one-way ANOVA followed by Bonferroni’s test. Representative images of immunofluorescence staining for (c) COX-1, (d) COX-2, and (e) mPGES-1 in hDPCs cultured with 200 ng/ml HMGB1 for 30 min. 4′-6-diamidino-2-phenylindole (DAPI; blue) was used to counterstain the nuclei. Data are representative of three independent experiments. Scale bar = 20 μm. (f) PGE₂ secretion from hDPCs was determined by ELISA following treatment with various concentrations of HMGB1 (50, 100, and 200 ng/ml) for 4 h. The results are expressed as mean ± SD of three independent experiments. *p < 0.05 compared with control group using one-way ANOVA.