[The effects of Nrf2 gene expression induced by RU486 at different doses on A549 cell damage induced by paraquat].

Objective: To observe the effects of Nrf2 gene expression induced by RU486 at different doses on A549 cell damage induced by paraquat (PQ).

Methods: After A549 cells transfected with Ad-RUNrf2 were treated by RU486 at the doses of 10(-10), 10(-9), 10(-8) and 10(-7) mol/L for 6 h, A549 cell cultures were exposed to 10(-3) mol/L of PQ for 48 h. Then qRT-PCR and EMSA assays were used to detect the expression of Nrf2 gene, and qRT-PCR and ELISA assays were utilized to measure the effects of Nrf2 gene on the expression of the inflammatory cytokines IL-6, IL-10 and TNF-α, apoptotic factors Caspase-3, Caspase-9 and Cytochrome C. The oxidation factors (CAT and MDA protein contents) were observed by Chemical Colorimetric Analysis.

Results: Nrf2 gene relative expression and protein contents increased with RU486 concentrations, and the above expression was the highest when the concentration of RU486 was 10(-7) mol/L, which was significantly higher than those in control and PQ exposure groups (P < 0.01 or P < 0.05). The relative gene expression and protein expression of IL-6 and TNF-α enhanced with the reduced concentrations of RU486, which were the lowest when RU486 concentration was 10(-7) mol/L, as compared with control and PQ exposure groups (P < 0.01 or P < 0.05), while the change of IL-10 content was the opposite. The relative expression of Caspase3, Caspase9 and Cytochrome C genes also increased with the reduced concentrations of RU486, which were the lowest when RU486 concentration was 10(-7) mol/L, as compared with control and PQ exposure groups (P < 0.01 or P < 0.05). The content of CAT enhanced with RU486 concentration, which was the highest when RU486 concentration was 10(-7) mol/L, as compared with control and PQ exposure groups (P < 0.05). But the change of MDA content was the contrary.

Conclusion: Nrf2 expression induced by RU486 can promote the balance of oxidation-antioxidation system in A549 cells and inhibit the inflammation and apoptosis factors, which has a protective effect on A549 cell injury induced by PQ.