Fig. 6
From: Role of PM2.5 in the development and progression of COPD and its mechanisms
Immunohistochemical staining of MMP9, MMP12, and TGF-β1 in lungs sections induced by PM2.5 exposure (400x) (a) and semiquantitative assessment of MMP9, MMP12, and TGF-β1 protein expression using Image-Pro Plus (b). Data are presented as mean ± SD (n = 6). *P < 0.05, ** P < 0.01, *** P < 0.001 vs control group; #P < 0.05, ## P < 0.01, ### P < 0.001 vs PM2.5 + CSE-exposed group