Fig. 2

Effects of protease inhibitors on inflammatory gene induction. A549 (a), Beas2B (b) and SAE (c) cells were treated with medium, dust extract (DE) (0.25 %) alone or dust extract (0.25 %) in the presence of 25 μg/ml α1-antitrypsin (α1-AT) or 25 μg/ml soybean trypsin inhibitor for 3 h. Beas2B cells (d) were first treated with medium or medium containing metalloproteinase inhibitor GM6001 (10 μM) for 1 h and then exposed to medium or dust extract (DE) (0.25 %) for 3 h. Levels of mRNAs were determined by qRT-PCR. Levels of each mRNA in dust extract treated cells were arbitrarily considered as 100 and relative levels in cells treated with a combination of dust extract and inhibitors are shown. Data are means ± SE (n = 3). *P < 0.05; **P < 0.01; ***P < 0.001; ns, not significant, compared with cells treated only with dust extract