UTI stimulates Nrf2 activity and up-regulates HO1 mRNA expression. At 24 h after final OVA challenge, cytoplasmic and nuclear levels of Nrf2 protein, Nrf2 DNA binding activity and tissue level of HO1 mRNA in lungs were determined. (A) Q-RT-PCR shows that UTI up-regulates HO1 mRNA expression in lungs. HO1 mRNA was normalized to GAPDH mRNA. Means ± SD of five mice per group. *P < 0.05, compared with control group. #P < 0.05, compared with OVA alone group. (B) Western blot photographs show that UTI increases nuclear and decreases cytoplasmic Nrf2 content, indicating Nrf2 nuclear translocation. (C and D) Western blot Nrf2 bands were quantified using densitometry and expressed as fold increase or decrease over control group. Means ± SD of four mice per group. *P < 0.05, compared with control group. #P < 0.05, compared with OVA alone group. (E) EMSA photograph shows that UTI stimulates Nfr2 DNA binding activity in lungs. Representative of three independent experiments.