ABSTRACT
Aim: To investigate the effect of Nrf2 pathway on the expression of MRP1 in mildly stable COPD mice. Methods: The mild COPD mouse model was established by passive cigarette smoking. The pathological changes of lung tissues were examined by HE staining. Immunohistochemistry and Western blot were used to detect the protein expression of MRP1, Nrf2 and HO-1. Results: Compared with normal group, each lung function index of the mild-moderate COPD model group was significantly lower, but compared with wide type(WT) model group, the reduction was more significant in Nrf2-/- model group. HE results showed diffuse inflammatory reaction and alveolar bronchial structure damage in alveolar of WT and Nrf2-/- model mice, and it was more pronounced in Nrf2-/- mice. Immunohistochemistry and Western blot results showed that the expression of MRP1 in lung tissue of Nrf2-/- normal mice was significantly reduced compared with the normal WT group. After passive cigarette smoking, The expression of MRP1, Nrf2 and HO-1 in WT model group increased significantly, but compared with Nrf2-/- normal mice, there was no significant change in the expression of MRP1 in Nrf2-/- model group. Conclusions: Mildly stable COPD mice may counteract the xenobiotic damage caused by cigarette smoke through up-regulating the expression of MRP1 protein, which may be associated with Nrf2 signaling activation.