Fig. 3

Mitochondrial morphology and mitochondria- and senescence-related proteins expression in primary alveolar type II (ATII) cells of non-smokers, smokers and COPD patients. The area of mitochondria (A), and percentage of mitochondrial fragmentation (B) and perinuclear mitochondrial compaction (C) are assessed by MitoTracker Green. Data are presented as the percentage changes compared to non-smokers. The red/green fluorescence value (D) is used to quantify the mitochondrial membrane potential detected by JC-1 staining. N = 8 in each group. Data are presented as individual and mean values. Representative fluorescent microscopy of JC-1 staining in primary ATII cells of non-smoker, smoker and COPD patient (E). The scale bar is 50 μm. Mitochondria-related proteins including phosphorylated-DRP1 (p-DRP1)/DRP1 (F), DRP1 (G), MFF (H), MFN2 (I), OPA1 (J) and senescence-related protein Klotho (K) are measured by Western blot. N = 8 in each group. Every panel incorporates an illustrative Western blot image, and data are presented as individual and mean values of each protein. ^*p < 0.05, ^**p < 0.01, ^***p < 0.001