T-2 toxin induces ER stress-dependent liver injury via mitophagy-mediated ER-phagy suppression: Berbamine blocks SNARE complex for hepatoprotection.

T-2 toxin is a persistent, bioaccumulative environmental contaminant that poses major health threats to humans and animals. Endoplasmic reticulum (ER) stress and autophagy are two interconnected stress responses critical for maintaining cellular homeostasis. Berbamine (BBM) is an important member of bis-benzy lisoquinoline alkaloid with diverse biological activities. This study aimed to identify the molecular target of BBM against T-2 toxin-induced hepatotoxicity, focusing on autophagy-ER stress crosstalk. We systematically evaluated autophagy and ER stress in human HepaRG cells using immunoblotting, transmission electron microscopy and an autophagy reporter assay. T-2 toxin was found to concurrently activate PINK1/Parkin-mediated mitophagy and suppress Keap1-mediated FAM134B ubiquitination-dependent ER-phagy, thereby triggering ER stress. Integrated evidence from molecular dynamics and western blot demonstrated that BBM upregulated and stabilized BNIP3, blocking the VAMP8-SNAP29 interaction to inhibit T-2 toxin-induced autophagy and subsequent ER stress. Moreover, in vivo mouse experiments demonstrated that 30 mg/kg BBM significantly alleviated T-2 toxin-induced liver injury by suppressing both autophagic flux and ER stress; BBM significantly reduced serum levels of liver enzymes, ALT, and AST. Collectively, our findings elucidate a novel mechanism wherein T-2 toxin-induced mitophagy inhibits ER-phagy to drive ER stress-mediated liver injury and highlight the therapeutic potential of BBM in alleviating T-2 toxin-induced liver injury.