Fig. 5. Increased level of PAR2 found in lung homogenates and lung epithelial cells from CSE-treated mice and from smokers and COPD patients.

a Experimental protocols for a murine model of emphysema. C57BL/6 mice were intratracheally instilled with vehicle or CSE as described in the materials and methods section. Mice (n = 4 per group) were sacrificed at week 8 after first instillation to isolate lungs. b Lung homogenates from mice were subjected to western blot analysis for PAR2 and GAPDH. Gel data were quantified using Scion image densitometry (right panel). Data represent the mean ± SE; **P < 0.05. c PAR2 immunohistochemistry in the lung tissues from mice. PAR2 was increased in lung epithelial cells of CSE-treated mice (arrows). d Total lung lysates obtained from normal (n = 4), smokers (n = 4), and COPD patients (n = 4) (c) were subjected to western blot analysis for PAR2 and GAPDH. Gel data were quantified (right panel). Data represent the mean ± SE; **P < 0.05. e PAR2 immunohistochemistry in the lung tissues from human patients. Arrows identify the epithelial cells. Original magnifications, ×200