Figure 3.

Flow cytometric analysis of apoptosis/necrosis stained with Annexin V-FITC and PI in lung epithelial cells 48 h (2 cycles) after exposure to hyperoxia, radiation, and double-hit combination challenge. Non-tumorigenic murine alveolar type II epithelial cells (C10) were evaluated after 2 cycles of hyperoxia and radiation exposure and evaluated by flow cytometric analysis of apoptosis/necrosis stained with Annexin V-FITC and PI. (a) Representative flow cytograms depicting Annexin V-FITC and PI staining showing the distribution of necrotic and apoptotic cells; (b) Percentages (%) of apoptotic (positive Annexin V-FITC) and necrotic (negative Annexin V-FITC and positive PI) cells in every cohort, as compared to untreated cells. Data are represented as the mean ± SEM. * p < 0.05 for each exposure condition as it compares with the unexposed control (CTL); ^# p < 0.05 for significant differences between O₂-alone compared to O₂ + IR; ^§ p < 0.05 for significant differences between IR-alone compared to O₂ + IR.