Abstract: Objective To study the role of receptor-interacting protein kinase 3 ( RIPK3) in acute liver failure induced by lipopolysaccharide / D-galactosamine (LPS / D-GalN). Methods SPFgrade male BALB / c mice were randomly divided into 3 groups (n = 5). The ALF animal model wasestablished by intraperitoneal injection of LPS combined with D-GalN. One hour before intraperitoneal drug injection, the mice were pretreated with intravenous injections of 0. 1 % DMSO and the RIPK3-specific antagonist GSK872 (dissolved in 0. 1 % DMSO), respectively. The degree of liver injury was assessed by blood biochemical tests and histological changes in the liver tissue. PCR was used to detect the expression levels of mRNA, while Western blotting and immunohistochemistrywas used to detect the expression levels of proteins. Results Animal experimental results showedthat LPS / D-GalN-challenged mice exhibited significant inflammatory hemorrhagic necrotic damageand increased infiltration of F4 / 80 + cells in liver tissues, and a notable elevation of ALT and AST levels in blood (both P < 0. 01) when compared with the control. In addition, the mRNA levels of F4 / 80, Mcp-1, Tnf-α, Il-6, Ripk3 and Mlkl, as well as the levels of RIPK3 protein and pMLKL / MLKL protein ratio, were all upregulated in liver tissues in comparison with the controlgroup, with all differences being statistically significant ( all P < 0. 05). Compared to the mice in the LPS / D-GalN group, the GSK872-pretreated mice displayed a marked reduction in the degree ofliver inflammatory injury, a significant decrease in the infiltration of F4 / 80 + cells in the liver, anda substantial decline in serum ALT and AST levels (both P < 0. 01). The mRNA levels of F4 / 80,Mcp-1, Tnf-α, Il-6, Ripk3, and Mlkl as well as the levels of RIPK3 protein and p-MLKL / MLKLprotein ratio, were all downregulated in liver tissues, with all differences being statistically significant (all P< 0. 05). Conclusion The RIPK3 inhibitor GSK872 can significantly block the expression of RIPK3 in LPS / D-GalN-induced ALF in mice, mitigate liver tissue damage and inflammatorycell infiltration, and suppress the expression of necroptosis-related proteins. This suggests thatRIPK3 might promote the pathogenesis of ALF by influencing the molecules of the hepatic necroptotic apoptosis pathway.

Key words: acute liver failure, necroptosis, hepatocytes, receptor-interacting protein kinase 3