Bacteroides fragilis enterotoxin upregulates heme oxygenase-1 in dendritic cells via reactive oxygen species-, mitogen-activated protein kinase-, and Nrf2-dependent pathway

Figure 7 Mitogen-activated protein kinases signals associated with heme oxygenase-1 expression in Bacteroides fragilis enterotoxin-stimulated dendritic cells. A and B: Bone marrow (BM)-derived dendritic cells (DCs) (A) and DC2.4 cells (B) were stimulated with Bacteroides fragilis toxin (BFT) (100 ng/mL) for the indicated periods. ERK1/2, p38, and JNK activities were measured by immunoblot analysis. Results are representative of three independent experiments. C: BM-derived DCs were preincubated with SB203580 (open circle), PD98059 (open triangle), or SP600125 (open square) for 30 min, and then stimulated with BFT (100 ng/mL) for another 24 h. Expression levels of heme oxygenase-1 (HO-1) protein were determined by ELISA. Data are expressed as the mean % increase relative to unstimulated controls ± SE (n = 5). ^aP < 0.05 vs BFT alone. HO-1: Heme oxygenase-1.