MAPK pathways mediate hyperoxia-induced oncotic cell death in lung epithelial cells.

Cell injury and cell death of pulmonary epithelium plays an important role in the pathogenesis of acute lung injury in animals exposed to prolonged hyperoxia. The aim of this study was to decipher the molecular mechanisms modulating cell death induced by hyperoxia in lung epithelium. Cell death is thought to be either apoptotic, with shrinking phenotypes and activated caspases, or oncotic, with swelling organelles.

Distinct patterns of apoptosis in the lung during liquid ventilation compared with gas ventilation.

To determine whether liquid ventilation (LV) causes less cell injury and improves lung function compared with conventional gas ventilation (GV), we analyzed pulmonary physiological profiles, lung histology, and cell death in 110- and 120-day preterm lambs, which were randomized to receive either ventilation modality on FI(O(2)) = 1. LV lungs were well expanded with adequate pulmonary function, whereas GV animals exhibited marked atelectasis, poor pulmonary function, and increased mortality. Both ventilatory strategies induced marked lung cell apoptosis, but with distinct patterns of distribution.