PICK1 mediates reactive oxygen species release and apoptosis in endotoxin-induced acute lung injury through interacting with PKCα and Ca 2+ /Calmodulin-activated Kinase II (CaMKII)

Background: The pathophysiological mechanism of sepsis-related acute lung injury, which leads to a major cause of mortality in critically ill patients remains ambiguous. Our previous study demonstrated that PICK1 played a pivotal role in regulating antioxidants (Glutathione) synthesis via affecting xCT, however, its effects on oxidants was still unknown. This study aimed to explore whether PICK1 mediates reactive oxygen species release and apoptosis in endotoxin-induced acute lung injury, thereby funding effective treatments for ALI. Methods: : In this study, male C57BL/6 mice or PICK1 knock out mice and mouse macrophage cell line, RAW264.7 were treated with LPS to establish endotoxin-induced acute lung injury model in vivo and in vitro. FSC-231 were used to disturb the interaction between PICK1 and PKCα. KN-93 were used to inhibit the activity of CaMKII. The alterations of protein PICK1, PKCα, CaMKII, p-CaMKII, BAX, Bcl-2, Cleaved-Caspase 3 were observed. Meanwhile, PICK1-PKCα complexes, PICK1-p-CaMKII complexes were detected. Cell Viability, ROS release, and cell apoptosis were examed as well. Results: : We found that in endotoxin-related ALI, the content of PICK1 and p-CaMKII were augmented, while, PKCα were activated and declined. LPS stimulated the formation of PICK1-PKCα complexes, PICK1-p-CaMKII complexes. Moreover, PICK1 knock out exacerbate ROS release and apoptosis. Either PDZ or BAR domain disruption could mimic the effects of PICK1 knock out. Conclusions: : Our results suggest that PICK1 mediates ROS release and apoptosis via interaction with PKCα and CaMKII.