Tripartite Motif-Containing 27 Attenuates Liver Ischemia/Reperfusion Injury by Suppressing Transforming Growth Factor β-Activated Kinase 1 (TAK1) by TAK1 Binding Protein 2/3 Degradation.

Abstract

Background and AimsHepatic ischemia‐reperfusion (I/R) injury, which mainly involves inflammatory responses and apoptosis, is a common cause of organ dysfunction in liver transplantation (LT). As a critical mediator of inflammation and apoptosis in various cell types, the role of tripartite motif‐containing (TRIM) 27 in hepatic I/R injury remains worthy of study.Approach and ResultsThis study systemically evaluated the putative role of TRIM27/transforming growth factor β–activated kinase 1 (TAK1)/JNK (c‐Jun N‐terminal kinase)/p38 signaling in hepatic I/R injury. TRIM27 expression was significantly down‐regulated in liver tissue from LT patients, mice subjected to hepatic I/R surgery, and hepatocytes challenged by hypoxia/reoxygenation (H/R) treatment. Subsequently, using global Trim27 knockout mice (Trim27‐KO mice) and hepatocyte‐specific Trim27 transgenic mice (Trim27‐HTG mice), TRIM27 functions to ameliorate liver damage, reduce the inflammatory response, and prevent cell apoptosis. In parallel in vitro studies, activating TRIM27 also prevented H/R‐induced hepatocyte inflammation and apoptosis. Mechanistically, TRIM27 constitutively interacted with the critical components, TAK1 and TAK1 binding protein 2/3 (TAB2/3), and promoted the degradation of TAB2/3, leading to inactivation of TAK1 and the subsequent suppression of downstream JNK/p38 signaling.ConclusionsTRIM27 is a key regulator of hepatic I/R injury by mediating the degradation of TAB2/3 and suppression of downstream TAK1‐JNK/p38 signaling. TRIM27 may be a promising approach to protect the liver against I/R‐mediated hepatocellular damage in transplant recipients.