Cysteiny Aspartate Specific Proteinase-1-mediated Glycogen Synthase Kinase-3 Promotes Acute Liver Failure Induced By D-galactosamine/Lipopolysaccharide In Mice

Objective:To analyze the function of cysteinyl aspartate specific proteinase-1(caspase-1)in a mouse model of D-galactosamine(D-GalN)/ lipopolysaccharide(LPS)-induced acute liver injury(ALF)and the possible mechanism.Methods:Firstly,C57BL/6 mice were randomly divided into control group,ALF 2h group,ALF 4h group and ALF 6h group(n=10 each). Secondly,C57BL/6 mice were randomly divided into control group, Z-WEHD-FMK-single treatment group, ALF group and Z-WEHD-FMK-treated ALF group(n=10 each,Z-WEHD-FMK in DMSO). For inducing ALF, the mice were injected intraperitoneally with D-GalN( 450mg/kg) and LPS( 10μg/kg).Z-WEHD-FMK( 3mg/kg), the selective agonist of caspase-1, was administered via tail two hours prior to the onset of ALF. Two,four and six hours after D-GalN/LPS exposure in the first study,and 6h after D-GalN/LPS exposure in the second study,mice were anesthetized and blood was collected. Liver samples were harvested for histology and RNA extraction. The serum ALT and AST levels were determined to reflect the function of liver. The protein expression of caspase-1 and glycogen synthase kinase-3beta was analyzed by Western blotting. The transcriptional levels of TNF-α,IL-1β,IL-18 and IL-33 were analyzed by Quantitative PCR.Results:The gene and protein expression of caspase-1 were gradually increased during the development of ALF. Compare with the model group, the liver architecture of Z-WEHD-FMK-treated mice was better preserved. The serum ALT and AST levels in Z-WEHD-FMK-treated group were significantly lower[ALT :(479.2±39.5)U/L vs(998.5±60.4)U/L,P<0.05;AST:( 478.5±28.6)U/L vs( 1180.7±91.4)U/L,P<0.05].The gene expressions of TNF-α,IL-1β,IL-18 and IL-33 were significantly suppressed in Z-WEHD-FMK-treated group. By western blotting analysis, we found that Z-WEHD-FMK itself inhibit glycogen synthase kinase-3 beta by a significant increase of its phosphorylation.Conclusion:This study demonstrated that in ALF process caspase-1 activation modulated liver innate immune activation via a GSK-3-dependent mechanism which favored the development of a pro-inflammation response and lead to liver tissue damages. Caspase-1may be a potential new therapeutic target for ALF.