Ursodeoxycholyl lysophosphatidylethanolamide protects against hepatic ischemia/reperfusion injury via phospholipid metabolism-mediated mitochondrial quality control

Abstract

Mitochondrial dysfunction is the leading cause of reactive oxygen species (ROS) burst and apoptosis in hepatic ischemia/reperfusion (I/R) injury. Ursodeoxycholyl lysophosphatidylethanolamide (UDCA-LPE) is a hepatotargeted agent that exerts hepatoprotective roles by regulating lipid metabolism. Our previous studies have shown that UDCA-LPE improves hepatic I/R injury by inhibiting apoptosis and inflammation. However, the role of UDCA-LPE in lipid metabolism and mitochondrial function in hepatic I/R remains unknown. In the present study, we investigated the role of UDCA-LPE in hepatic I/R by focusing on the interface of phospholipid metabolism and mitochondrial homeostasis. Livers from 28-week-old mice, primary hepatocytes and HepG2 cells were subjected to in vivo and in vitro I/R, respectively. Analyses of oxidative stress, imaging, ATP generation, genetics, and lipidomics showed that I/R was associated with mitochondrial dysfunction and a reduction in phospholipids. UDCA-LPE alleviated mitochondria-dependent oxidative stress and apoptosis and prevented the decrease of phospholipid levels. Our study found that cytosolic phospholipase A2 (cPLA2), a phospholipase that is activated during I/R, hydrolyzed mitochondrial membrane phospholipids and led to mitochondria-mediated oxidative stress and apoptosis. UDCA-LPE inhibited the interaction between cPLA2 and mitochondria and reduced phospholipid hydrolysis-mediated injury. UDCA-LPE might regulate the crosstalk between the phospholipid metabolism and the mitochondria, restore mitochondrial function and ameliorate I/R injury.