LPS Activated Macrophages Induced Hepatocyte Pyroptosis via P2X7R Activation of NLRP3 in Mice.

BACKGROUND

Pyroptosis is a programmed cell death related to caspase-1, accompanied by the secretion of pro-inflammatory cytokines.

OBJECTIVES

To explore the effects of LPS on the P2X7R/NLRP3 pathway in macrophages, and hepatocytes pyroptosis in mice.

METHODS

LPS was used to establish an animal model of the acute liver injury. The macrophage RAW264.7 was induced by LPS to establish a cell model. The P2X7R inhibitor A438079 and agonist BZATP were added. RAW264.7 was co-cultured with AML-12 cells. Pyroptosis and the ratio of CD11b+CD86+/CD11b+CD206+ were analyzed by flow cytometry. ELISA, WB, and qRT-PCR were applied to analyze factors involved in the P2X7R/NLRP3 pathway.

RESULTS

LPS induced liver damage in mice, promoted cell pyroptosis and increased the levels of IL-18, IL-1β, ALT, AST, and TBIL. P2X7R, GSDMD, and GSDMD-N expressions also increased in the LPS group. LPS induced macrophage activation in vivo. NLRP3, ASC, P2X7R, and caspase-1 expressions in vitro promoted. ELISA confirmed that the IL-1β and IL-18 levels repressed in the BZATP (P2X7R agonist) group, while the trend was opposite in the A438079 (P2X7R inhibitor) group. LPS activated the P2X7R/NLRP3 pathway in macrophages. After RAW264.7 was co-cultured with AML-12 cells, the pyroptosis of AML-12 cells promoted but the proliferation decreased in the BZATP group. GSDMD and GSDMD-N expressions promoted in the BZATP group, while the trend was opposite in the A438079 group.

CONCLUSION

LPS activated macrophages via P2X7R activation of NLRP3 and induced hepatocyte pyroptosis, which provided novel potential targets for the liver injury treatment.