Figure 1.

Pseudomonas aeruginosa (PA) induces lung inflammation and oxidative stress. Bronchoalveolar lavage (BAL) was collected at 24 and 48 hours after bacterial treatment. (A) A cell pellet was resuspended in 200 μl PBS for cell counting. (B) BAL protein and (C) H₂O₂ concentrations are shown. P. aeruginosa induced significant lung injury, as evidenced by increased BAL cell count, protein content, and reactive oxygen species (ROS) production. *P < 0.01, compared with PBS control samples (n = 4). (D) Human lung microvascular endothelial cells (HLMVECs), cultured in 35-mm dishes to approximately 90% confluence, were exposed to Pseudomonas aeruginosa strain 103 (PA103) at multiplicities of infections (MOIs) 1, 5, and 10 for 9 hours. Cells were then loaded with 5-(and-6)-carboxy-2',7'-dichlorodihydro-fluorescein diacetate (carboxy-H₂DCFDA) (5 μM) for 30 minutes, and the oxidation of DCFDA was monitored under fluorescent microscopy (×200). Scale bars, 30 μm. (E) ROS production in each group was quantified. (F) H₂O₂ concentrations in culture media were assayed. PA103 induced significant ROS production in HLMVECs in a dose-dependent manner. *P < 0.05 and **P < 0.01, versus PBS control samples (n = 6). con, control.