c-Jun N-terminal kinase mediates hepatic injury after rat liver transplantation

Background. Orthotopic liver transplantation (OLT) requires cold ischernic storage followed by warm reperfusion. Although c-Jun N-terminal kinase (JNK) is rapidly activated after OLT, the functional consequences of JNK activation are unknown. The aim of this study was to address the role of INK after OLT using the selective INK inhibitor CC-401. Methods. Donors, recipients, or stored liver explants were treated with vehicle or JNK inhibitor before OLT by an arterialized two-cuff method with 40 hours of cold storage. Recipients were assessed for 30-day survival, and graft injury was assessed over time by hepatic histology, serum transaminases, caspase 3 activation, cytosolic cytochrome c, and lipid peroxidation. Results. Survival after OLT increased after donor plus storage and storage only treatment with JNK inhibitor (P<0.05). Treatment of recipient only did not improve survival. Increased survival correlated with improved hepatic histology and serum aspartate aminotransferase levels. JNK inhibition significantly decreased nonparenchymal cell killing at 60 minutes after reperfusion (P<0.05) and pericentral necrosis at 8 hours after reperfusion (P<0.01). JNK inhibition decreased cytochrome c release, caspase 3 activation (P<0.05), and lipid peroxidation (P<0.05). JNK inhibition also transiently blocked phosphorylation of c-Jun at 60 minutes after reperfusion (P<0.05) without affecting other MAPK signaling, including p-38 and Erk activation. Conclusions. JNK inhibition decreases hepatic necrosis and apoptosis after OLT, suggesting that JNK activation promotes cell death by both pathways. Inhibition of JNK maybe a new therapeutic strategy to prevent liver injury after transplantation.