Figure 6.

Effect of NBO on apoptosis and mitogen-activated protein kinase (MAPK) signaling pathways. Cells were treated with room air or hyperoxia (85% O₂) for 24 h. Then, A549 cells were harvested and RNA was isolated using Trizol. (a) mRNA expression of caspase-3, -9, Bax, Bcl-2 and p53 was examined by reverse transcription polymerase chain reaction (RT-PCR). PCR products were resolved on a 2% agarose gel. (b) The expression levels of apoptosis and cell survival-related genes, such as poly (ADP-ribose) polymerase (PARP), caspases, p53, p21, Bax and Bcl-2 were examined in total protein by Western blotting. (c) Protein levels of extracellular regulated kinase (ERK) and c-Jun N-terminal kinase (JNK) were examined in total protein by Western blotting.