Figure 1.

Increased sensitivity of Nrf2−/− mice to CS-induced oxidative stress. (A) Immunohistochemical staining for 4HNE in lung sections from Nrf2+/+ and Nrf2−/− mice exposed to air or CS for 1 mo. Lung sections from the CS-exposed Nrf2−/− mice show greater staining for 4HNE than the CS-exposed Nrf2+/+ mice and the respective air-exposed control mice. The image is representative of results from three animals in each group. Magnification: ×40. (B) Immunohistochemical staining clearly shows the presence of an increased number of 8-Oxo-dG–positive alveolar epithelial cells in the airways (indicated by arrow in the inset and middle bottom panel) of CS-exposed Nrf2-deficient mice compared with wild-type mice (middle upper panel). Airways of room air–exposed mice shows few or no 8-oxo-dG–positive cells (left panels). Magnification: ×20 (inset magnification: ×40) (n = 3).