Figure 2.

Formation of NETs, components of NETs and mechanisms affecting ARDS. (A) The formation of NETs can be divided into NADPH oxidase-dependent and independent formations. ① Activation of PKC leads to activation of NADPH oxidase and the production of ROS. ROS stimulates MPO and NE to migrate to the nucleus, NE triggers histone degradation, and MPO collaborates with NE to promote chromatin decondensation. ② Activated PAD4-mediated histone citrullination leads to chromatin decondensation [9]. (B) The major components of NETs include DNA, histones, NE and MPO. (C) NETs and their components can cause pulmonary tissue edema, damage alveolar epithelial cells and microvessels, cause the formation of immune thrombosis and activation of endothelial cells, and mediate the pyroptosis of macrophages and the release of downstream cytokines.