Nci h441 h441

Rat alveolar type II-like epithelial (L2) cells were provided to us by Dr Judith Creighton, previously at the University of Alabama at Birmingham. Their origin was characterised and verified using the presence of human and rat genes using PCR, immunohistochemistry and Western blots of appropriate markers (supplementary figure S1). NCI-H441 (H441) (ATCC HTB-174), a human club-like cell line, was purchased from ATCC. L2 and H441 cells were cultured as described (supplementary material: cell culture), plated on T25 flasks and allowed to grow to confluence. 24 h prior to exposure, cells were lifted from the flasks using trypsin-EDTA (Atlanta Biologicals) and seeded in six-well plates coated with collagen (0.1 mg·mL⁻¹; Sigma-Aldrich) at 5×10⁴ cells·cm⁻² and incubated overnight at 37°C in a humidified atmosphere of 95% air and 5% CO₂. Cells were exposed to Br₂ gas at 100 ppm in a cylindrical glass chamber for 10 min, as previously described [19 (link), 20 (link)]. Immediately after exposure, cells were placed in a humidified incubator at 37°C vented with 95% air and 5% CO₂ until used for the various experiments. Control cells remained in the same incubator for similar periods of time. AICAR or vehicle was added into the cell culture medium 6 h after Br₂ exposure at a final concentration of 800 μM.