E3 ubiquitin ligase RNF11 protects against liver ischemia reperfusion injury through HINT1 degradation-mediated PI3K/AKT activation

Abstract Background: Liver ischemia reperfusion injury (IRI) is a major cause of postoperative liver dysfunction. RNF11, a conserved E3 ubiquitin ligase involved in inflammation, oxidative stress, and apoptosis, may be an important regulator of liver IRI.Methods: The role and mechanism of RNF11 in liver IRI were investigated using a mouse IRI model and AML12 hypoxia/reoxygenation (H/R) cells. RNF11 expressions were examined by RT-qPCR, Western blot, and immunohistochemistry. AAV- or lentivirus-mediated knockdown and overexpression were used to modulate RNF11. Liver injury was evaluated by serum biochemical parameters, histopathological changes, inflammatory cytokines, and apoptotic markers. RNA sequencing, KEGG analysis, co-immunoprecipitation, and ubiquitination assays were performed to explore mechanisms.Results: RNF11 expression was markedly downregulated in IRI livers and H/R-treated AML12 cells. RNF11 knockdown aggravated liver damage, with higher ALT/AST levels, increased necrosis, enhanced inflammatory infiltration, and upregulated proinflammatory cytokines, whereas RNF11 overexpression alleviated liver IRI in vivo and in vitro. RNF11 interacted with histidine triad nucleotide-binding protein 1 (HINT1) and activated PI3K/AKT signaling. The PI3K/AKT inhibitor LY294002 abrogated the anti-inflammatory and anti-apoptotic effects of RNF11. RNF11 promoted K48-linked polyubiquitination and proteasomal degradation of HINT1. Conclusion: RNF11 is a critical regulator of liver IRI that protects against inflammation and apoptosis by targeting HINT1 for K48-linked polyubiquitination and activating PI3K/AKT signaling, suggesting a potential therapeutic target for liver IRI.