Abstract：Background: Acute liver failure (ALF) is an unpredictable and life-threatening critical illness. The pathological characteristic of ALF is massive necrosis of hepatocytes and lots of inflammatory cells infiltration which may lead to multiple organ failure.
Methods: Animals were divided into 3 groups, normal, thioacetamide (TAA, ALF model) and TAA + AGK2. Cultured L02 cells were divided into 5 groups, normal, TAA, TAA + mitofusin 2 (MFN2)-siRNA, TAA + AGK2, and TAA + AGK2 + MFN2-siRNA groups. The liver histology was evaluated with hematoxylin and eosin staining, inositol-requiring enzyme 1 (IRE1), activating transcription factor 6 β(ATF6 β), protein kinase R (PKR)-like endoplasmic reticulum kinase (PERK) and phosphorylated-PERK (p-PERK). C/EBP ho- mologous protein (CHOP), reactive oxygen species (ROS), MFN2 and glutathione peroxidase 4 (GPX4) were measured with Western blotting, and cell viability and liver chemistry were also measured. Mitochondria- associated endoplasmic reticulum membranes (MAMs) were measured by immunofluorescence.
Results: The liver tissue in the ALF group had massive inflammatory cell infiltration and hepatocytes necrosis, which were reduced by AGK2 pre-treatment. In comparison to the normal group, apoptosis rate and levels of IRE1, ATF6 β, p-PERK, CHOP, ROS and Fe2 + in the TAA-induced ALF model group were sig- nificantly increased, which were decreased by AGK2 pre-treatment. The levels of MFN2 and GPX4 were decreased in TAA-induced mice compared with the normal group, which were enhanced by AGK2 pre- treatment. Compared with the TAA-induced L02 cell, apoptosis rate and levels of IRE1, ATF6 β, p-PERK, CHOP, ROS and Fe2 + were further increased and levels of MFN2 and GPX4 were decreased in the MFN2- siRNA group. AGK2 pre-treatment decreased the apoptosis rate and levels of IRE1, ATF6 β, p-PERK, CHOP, ROS and Fe2 + and enhanced the protein expression of MFN2 and GPX4 in MFN2-siRNA treated L02 cell. Immunofluorescence observation showed that level of MAMs was promoted in the AGK2 pre-treatment group when compared with the TAA-induced group in both mice and L02 cells.
Conclusions: The data suggested that AGK2 pre-treatment had hepatoprotective role in TAA-induced ALF via upregulating the expression of MFN2 and then inhibiting PERK and ferroptosis pathway in ALF.
2024, Vol. 23 
