Figure 2

Reduced RelB mRNA and protein expression in human lung fibroblasts from At Risk and COPD subjects. (A) RelB western blot- RelB protein expression was detected in most lung fibroblasts examined at the predicted MW of 68 kDa. A faster migrating band of ≈ 55 kDa was also detected. There was an apparent decrease in RelB protein levels in the majority of lung fibroblasts from At Risk and COPD subjects. Sample numbers refer to lung fibroblasts from different individuals (Normal = 6; At Risk = 15; COPD = 12). (B) RelB protein densitometry- there was a significant decrease in RelB protein expression in lung fibroblasts derived from the lungs of At Risk (0.41 ± 0.08) as well as COPD subjects (0.38 ± 0.07) (*p = 0.0022 compared to fibroblasts from Normal subjects). There was no significant difference in RelB levels between At Risk and COPD fibroblasts. Results are expressed as the mean ± SEM and each symbol represents fibroblasts from a different individual. Densitometry is based on the band detected at the predicted MW of 68 kDa. (C) RelB mRNA- Relative RelB mRNA expression was significantly lower in At Risk (0.5 ± 0.06) and COPD (0.57 ± 0.07) compared to Normal (1.0 ± 0.18; * p < 0.0044) fibroblasts. Results are expressed as the mean ± SEM (fold-change) of RelB levels normalized to the Normal fibroblasts. (D) RelB localization: Immunofluorescent imaging of quiescent lung fibroblasts revealed that the majority of RelB in Normal, at Risk and COPD lung fibroblasts was localized to the cytoplasm (red colour) with minimal RelB evident in the nucleus (blue colour). Note that there appeared to be qualitatively less RelB (based on intensity) in the At Risk and COPD-derived lung fibroblasts. Representative images based on two independent experiments.