Fig. 4

The comparable effects of ozone and H₂O₂ and the induced-expression of HSP20 in human AECs. Human bronchial epithelial cell line 16-HBE were cultured in air–liquid-interface. a Cell viability was measured with MTS after being stimulated with 2.0 ppm ozone or series of hydrogen peroxide (H₂O₂) (0, 25, 50, 100, 200, 400, 800 μM) for 0.5, 1, 2, 4 h. b 4-Hydroxynonenal (4-HNE) in supernatants and c 8-hydroxy-deoxyguanosine (8-OHdG) in DNA extracts were measured with ELISA in 16 HBE cells stimulated with 2.0 ppm ozone or series of hydrogen peroxide (H₂O₂) (0, 50, 100, 200 μM) for 0.5, 1, 2 h, respectively. BEAS-2B cells were cultured in submergence and stimulated with a series of H₂O₂ (0, 0.1, 1.0, 10, 100 μM) for 1 h and then were harvested 0, 12, and 24 h later. Cell viability was evaluated with MTT (D). e, f The mRNA and protein expression of HSP20 were measured with Western blot (same volume of protein sample added to gels) and RT-qPCR (same amount of DNA sample added to microplates), respectively. These measurements were performed with triplicates. g The immunocytochemistry (IHC) staining for HSP20 on BEAS-2B cells stimulated with 10 μM H₂O₂ (PBS as control) for 1 h and harvested 12 h after. Data are presented as mean ± SD