Figure 2.

High DNA damage and the impairment of DNA damage repair in ATII cells in patients with emphysema. Freshly isolated ATII cells from non-smokers (NS), smokers (SM) and patients with emphysema (EM) were used to determine γH2AX expression by Western blotting (A). Densitometric quantification of γH2AX levels normalized to GAPDH and non-smokers (B). Human lung sections were co-stained for SP-C to identify ATII cells (red), γH2AX (green) and nuclei (DAPI, blue) by immunohistofluorescence (magnification 10 × 63) (C). The relative fluorescence intensity of γH2AX expression in ATII cells is also shown (D). Representative p53 and p21 expression from the same Western blotting (E) and densitometric analysis (F) in ATII cells obtained from non-smokers, smokers and emphysema patients. Apoptotic ATII cells were detected using SP-C (red), caspase 3 (green) and DAPI (blue) staining by immunohistofluorescence (G) and quantification is also shown (H). Decreased number of ATII cells using SP-C staining (red) in lung tissue sections from emphysema patients by immunohistofluorescence (DAPI, blue; magnification 10 × 63) (I) and quantification (J). Data are presented as means ±s.e.m (*p < 0.05). Cultured ATII cells isolated from control non-smokers were treated with CSE for 24 h (K). Lane 1 – control, lane 2–1% CSE, lane 3–3% CSE and lane 4–6% CSE. Cell lysates were subjected to Western blotting to determine protein expression (N = 3 per group).