Pulmonary AT2 cell apoptosis after CBDL.

<p>(<b>A</b>) Representative images of TUNEL staining (green, shown by arrows) and quantitation of TUNEL positive cells in control and 3-week CBDL lung. Scale bar = 50 µm. (<b>B</b>) Immunofluorescence double-labeling of SP-C (red) and TUNEL (green) in alveolar regions of 3-week CBDL animal lung. Apoptotic AT2 cells were marked with arrows. Scale bar = 25 µm. (<b>C</b>) Representative immunoblots and quantitation of cleaved caspase-3 protein levels in control, 1-week and 3-week lung (left), and in isolated AT2 cells from control and 3-week CBDL lung (right). GAPDH was included as a loading control. Cleaved caspase-3 protein levels were normalized to the levels of GAPDH. Relative to control, CBDL lung had increased apoptotic AT2 cells (TUNEL and SP-C double positive). In parallel, cleaved caspase-3 protein levels were upregulated in both CBDL lung homogenates and isolated AT2 cells. Values are expressed as means ± SME. * <i>P</i><0.05 compared with control.