Cholestatic insult triggers alcohol-associated hepatitis in mice.

Background: Alcohol-associated hepatitis (AH) is a severe, potentially life-threatening form of alcohol-associated liver disease with limited therapeutic options. Existing evidence shows that biliary dysfunction and cholestasis are common in patients with AH and are associated with poorer prognosis. However, the role of cholestasis in the development of AH is largely unknown. We aimed to examine the hypothesis that cholestasis can be an important etiology factor for AH.

Methods: To study the interaction of cholestasis and alcohol, chronically ethanol (EtOH)-fed mice were challenged with a subtoxic dose of α-naphthylisothiocyanate (ANIT), a well-studied intrahepatic cholestasis inducer. Liver injury was measured by biochemical and histological methods. RNAseq was performed to determine hepatic transcriptomic changes. The impact of inflammation was assessed using an anti-LY6G antibody to deplete the neutrophils and DNase I to degrade neutrophil extracellular traps.

Results: ANIT synergistically enhanced liver injury following a 4-week EtOH feeding with typical features of AH, including increased serum levels of ALT, AST, and total bile acids, cholestasis, necrosis, neutrophil infiltration, and accumulation of neutrophil extracellular traps. RNAseq revealed multiple genes uniquely altered in the livers of EtOH/ANIT-treated mice. Analysis of differentially expressed genes suggested an enrichment of genes related to inflammatory response. Anti-LY6G antibody or DNase I treatment significantly inhibited liver damage in EtOH/ANIT-treated mice.

Conclusions: Our results support the hypothesis that cholestasis can be a critical contributor to the pathogenesis of AH. A combined treatment of EtOH and ANIT in mice presents biochemical, histological, and molecular features similar to those found in patients with AH, suggesting that this treatment scheme can be a useful model for studying Alcohol-associated Cholestasis and Hepatitis (AlChoHep).