FIG 4.

Alveolar macrophages from infected lungs are responsible for the expression of Nramp1 regulated by Nrf2. Alveolar macrophages were obtained from BAL fluids of wild-type and Nrf2^−/− mice 2 months after intranasal inoculation of 1 × 10⁷ CFU of MAC bacteria or saline (Cont). (A) Expression of Nrf2, Nramp1, and HO-1 in alveolar macrophages from infected lungs of wild-type and Nrf2^−/−mice. (B and C) Representative Western blots of Nrf2 expression (B) and its semiquantitative analysis (C) in lung nuclear extracts from wild-type mice that were infected with MAC bacteria or uninfected. Values were normalized to lamin B. (D) Representative fluorescence images of Nrf2 immunoreactivity (green) and nuclear staining with DAPI (blue) in BAL-recovered cells of MAC infected wild-type mice (magnification, ×200). (E) Semiquantitative analysis of the mean fluorescence density of Nrf2 staining in the nuclei of alveolar macrophages from each group of mice. The fold changes between MAC-infected alveolar macrophages and control alveolar macrophages (saline) are shown. Experiments were performed in duplicate with four mice in each group. Significant differences between infected mice and noninfected mice (*, P < 0.05) and between Nrf2^−/− mice and wild-type mice (#, P < 0.05) are shown. Data are means and SEM.