YAP1 protects against PM2.5-induced lung toxicity by suppressing pyroptosis and ferroptosis

Pollution from fine particulate matter (PM2.5) has become a major threat to public health and has been related to lung toxicity. One of the key regulators of the Hippo signaling system, Yes-associated protein 1 (YAP1), is speculated to play a role in ferroptosis development. Here, we focused on investigating the function of YAP1 in pyroptosis and ferroptosis, aiming to explore its therapeutic potential in PM2.5-induced lung toxicity. PM2.5-induced lung toxicity was induced in Wild-type WT and conditional YAP1-knockout mice, and lung epithelial cells were stimulatd by PM2.5 in vitro. We used western blot, transmission electron microscopy, and fluorescence microscopy to investigate pyroptosis- and ferroptosis-related characteristics. We found that PM2.5 leads to lung toxicity using mechanisms involving pyroptosis and ferroptosis. YAP1 knockdown impeded pyroptosis, ferroptosis, and PM2.5-induced lung damage, as shown by increased histopathology, higher levels of proinflammatory cytokines, GSDMD protein, lipid peroxidation, and iron accumulation, as well as increased NLRP3 inflammasome activation and decreased SLC7A11 expression. YAP1 silencing consistently promoted NLRP3 inflammasome activation and reduced SLC7A11 levels, aggravating PM2.5-induced cellular damage. In contrast, YAP1-overexpressing cells inhibited NLRP3 inflammasome activation and increased SLC7A11 levels, preventing pyroptosis and ferroptosis. Overall, our data suggest that YAP1 ameliorates PM2.5-induced lung injury by inhibiting NLRP3-mediated pyroptosis and SL7A11-dependent ferroptosis.