Fig. 2.

The loss of endothelial barrier integrity leads to pulmonary edema and hypoxemia in ALI/ARDS. The inflammatory mediator, bacterial toxins, and ROS cause dynamic changes in the cytoskeletal structure and inter-endothelial junctions, leading to an increase in endothelial permeability. Endothelial interactions with leukocytes, platelets, and coagulation enhance inflammatory response. Bacterial infection and inflammatory infiltration and cytokines induce EC death, causing the compromise of the structural integrity of lung endothelial barrier, eventually resulting in pulmonary edema, impaired gas exchange, and hypoxemia. ALI: Acute lung injury; ARDS: Acute respiratory distress syndrome; EC: Endothelial cells; ROS: Reactive oxygen species.