Figure 3.

Altered recovery of ciliated cells in airway epithelia of Mmp7-null mice after naphthalene-induced lung injury. (A) Lung sections were immunostained for acetylated tubulin (green; Clone 6-11B-1; Sigma-Aldrich, St. Louis, MO) to mark ciliated cells, club cell–specific protein (CCSP) (red; Biovendor, Candler, NC) to identify club cells, and 4′,6-diamidino-2-phenylindole (DAPI) (blue) as a nuclear stain. Epifluorescence images were captured using an Olympus BX-51 microscope (Olympus America, Center Valley, PA) with a ×20/0.70 air objective. Scale bar = 200 μm. Acetylated tubulin⁺ cells (B) and CCSP⁺ cells (C) were counted per millimeter of airway length. Only airways between 200 and 350 μm in diameter were evaluated. A minimum of five airways was randomly evaluated in various lung lobes for each sample. Four mice per genotype were evaluated at each time point. *P < 0.05. (D) Scanning electron micrographs of naphthalene-injured lungs. Dome-shaped club cells (arrowhead) are seen interspersed with ciliated cells (arrows) under uninjured (corn oil) conditions. Scale bar = 20 μm.