Effect of IPI549 on hepatic ischemia-reperfusion injury in mice

Abstract:

Objective：To investigate the effect of specific inhibition of PI3Kγ by IPI549 on hepatic ischemia-reperfusion injury in mice. Methods：C57BL/6J mice were used to establish a model of hepatic ischemia-reperfusion injury，and RAW264.7 macrophages were used to establish a model of hypoxia and reoxygenation. The mice and RAW264.7 macrophages were treated with the PI3Kγ in－hibitor IPI549，and alanine aminotransferase，HE staining，and terminal deoxynucleotidyl transferase-mediated dUTP nick-end label－ing were used to evaluate hepatic injury. Western blot was used to measure the changes in the protein expression of p110γ （PI3Kγ） in tissue and primary cells and the protein expression of tumor necrosis factor-α（TNF-α），c-Jun N-terminal kinase（JNK），and phos－phorylated JNK （p-JNK） in RAW264.7 cells during hypoxia and reoxygenation. ELISA was used to measure the level of TNF-α in cell supernatant. Results：Kupffer cells had significantly higher expression of p110γ than primary hepatocytes. Compared with the sham group，the ischemia-reperfusion injury group had a significant reduction in the protein expression of p110γ in liver tissue. The mice treated with the PI3Kγ inhibitor IPI549 showed aggravation of liver injury and cell apoptosis after hepatic ischemia-reperfusion，and GdCl3 pretreatment to block Kupffer cells alleviated the aggravation of cell injury and apoptosis in liver tissue caused by IPI549. In vitro experiments showed that IPI549 intervention of RAW264.7 cells increased the phosphorylation level of JNK，the protein expres－sion of TNF-α，and the secretion of TNF-α in cell supernatant. Conclusion：Intervention with the PI3Kγ inhibitor IPI549 can aggra－vate hepatic ischemia-reperfusion injury in mice，possibly by inhibiting PI3Kγ in Kupffer cells to affect activation of the JNK signaling pathway and exerting a pro-inflammatory effect