Tumour Necrosis Factor‐α Promotes Pyroptosis in Diabetic Liver Injury via the HMGB1 / TLR4 / MyD88 / NF ‐ κB Pathway

ABSTRACT Diabetic liver injury (DLI) is a serious inflammatory complication, with tumour necrosis factor‐alpha (TNF‐α) recognized as a key pro‐inflammatory cytokine. This study aimed to investigate the protective effect of TNF‐α inhibition on DLI and to elucidate the underlying molecular mechanisms, focusing on the novel role of pyroptosis. An integrated experimental approach was employed, commencing with in vitro studies in HepG2 hepatocytes to dissect the signalling pathway, followed by in vivo validation in Sprague–Dawley rats. In vitro assessments included the expression of pyroptosis‐related proteins (caspase1, Gasdermin D GSDMD), high mobility group protein B1 (HMGB1), and components of the Toll‐like receptor 4 (TLR4)/myeloid differentiation factor 88 (MyD88)/nuclear factor‐κB (NF‐κB) pathway under high glucose conditions with or without TNF‐α inhibition. In vivo measurements comprised liver function tests alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), triglycerides (TG), liver histopathology, and analysis of the HMGB1/TLR4/MyD88/NF‐κB pyroptosis axis in liver tissues. In vitro, TNF‐α inhibition mitigated high glucose‐induced hepatocyte pyroptosis and suppressed HMGB1 release and TLR4/MyD88/NF‐κB signalling; pharmacological blockade of HMGB1 replicated these effects. In vivo, recombinant human TNF receptor‐II:Fc fusion protein (rhTNFR:Fc) significantly improved liver function and histopathology in diabetic rats without affecting blood glucose levels, while also downregulating the expression of HMGB1/TLR4/MyD88/NF‐κB pathway components and key pyroptosis markers such as NOD‐like receptor family pyrin domain containing 3 (NLRP3). In conclusion, TNF‐α promotes DLI by driving hepatocyte pyroptosis through the HMGB1/TLR4/MyD88/NF‐κB signalling axis. Inhibition of TNF‐α confers potent hepatic protection independent of glycemic control, identifying it as a promising therapeutic strategy for DLI.