[Activation of Yes-associated protein (YAP) improves mouse acute liver failure by alleviating ferroptosis]

Objective To investigate the effects of YAP on the occurrence and progression of acute liver failure by regulating the ferroptosis pathway and its underlying mechanism. Methods A total of 20 8-week-old C57BL/6 mice were randomly divided into four groups: a control group, an acute liver failure model group, a YAP agonist XMU-MP-1 treatment group and a YAP inhibitor verteporfin treatment group, five mice for each group. HE staining was used to observe the pathological changes of hepatic inflammation and necrosis. Plasma alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels were detected by liver biochemistry. Iron (Fe), malondialdehyde (MDA), glutathione (GSH) determination kits were used to measure their levels in liver tissues of each group. The changes of hepatocyte mitochondrial in each group were observed by electron microscopy. Real time PCR and Western blot analysis were used to detect the mRNA and protein expressions of YAP, glutathione peroxidase 4 (GPX4) and 5-lipoxygenase (5-LOX). Results Compared with the control group, mice in the acute liver failure model group and the YAP inhibitor verteporfin treatment group showed severe liver tissue congestion with inflammatory cell infiltration and structural damage to hepatic lobules. Liver injury was alleviated in the XMU-MP-1 treatment group. With the occurrence of liver failure, plasma ALT and AST levels significantly increased, and liver function was improved in XMU-MP-1 treatment group. Electron microscopy showed that mitochondria in hepatocytes of mice with liver failure became smaller and bilayer membrane density increased, while mitochondria changes in the XMU-MP-1 group were alleviated. In addition, the acute liver failure model group showed an increase in Fe and MDA contents, decreased protein expressions of GPX4, and enhanced expression of 5-LOX, suggesting that ferroptosis was involved in acute liver failure in C57BL/6 mice. Ferroptosis was inhibited by activation of YAP. Conclusion Activation of YAP may ameliorate liver injury by inhibiting ferroptosis.