Figure 3.

The impaired NHEJ DNA damage repair pathway in ATII cells and lung tissue in emphysema. 53BP1 expression in freshly isolated ATII cells from control non-smokers (NS), smokers (SM) and patients with emphysema (EM) was analyzed by Western blotting (A). Densitometric quantification is also shown (B). 53BP1 (green) expression is shown in ATII cells identified by proSP-C staining (red) in lung tissue sections (nuclei - DAPI, blue) by immunohistofluorescence (magnification 10 × 63) (C). Quantification of fluorescence intensity is also shown (D). DNA ligase IV (E,F) and XRCC4 (G,H) expression in freshly isolated ATII cells was determined by Western blotting and densitometric quantification. XLF levels in ATII cells were determined by Western blotting (I), densitometric quantification (J) and RT-PCR (K). XLF levels were analyzed in lung tissue obtained from control non-smokers and smokers, and areas with mild (ME) and severe emphysema (SE) from the same patient by Western blotting (L,M). Expression of OGG1 (N,O) was analyzed in lung tissue obtained from areas with mild and severe emphysema from the same patient by Western blotting and quantification. Representative Western blotting images and densitometric quantification are shown for PARP1 (P,Q), DNA ligase III (R,S) and RAD51 expression (T,U) in freshly isolated ATII cells. Data are shown as mean values ± s.e.m. (N = 7 per group; *p < 0.05).