Phospholipase D2 drives cellular lipotoxicity and tissue inflammation in alcohol-associated liver disease

Abstract

Aims: Excessive alcohol consumption leads to alcoholic liver disease (ALD), a major contributing factor to cirrhosis and hepatocellular carcinoma. In the present study we investigated the involvement of phospholipase D2 (PLD2) in the pathogenesis of ALD.

Methods and materials: ALD was induced in mice by chronic and binge ethanol feeding (the NIAAA model). Cellular transcriptome was examined by RNA-seq.

Key findings: Analysis of RNA-seq datasets indicated that PLD2 expression was up-regulated in liver tissues and in hepatocytes during ALD pathogenesis. Exposure of hepatocytes to ethanol treatment led to an increase in PLD2 expression. Similarly, ethanol feeding in mice stimulated PLD2 expression in the liver. On the contrary, PLD2 knockdown in hepatocytes down-regulated expression of pro-inflammatory and pro-lipogenic genes and dampened lipid accumulation. Consistently, PLD2 knockdown in mice significantly ameliorated ALD pathogenesis as evidenced by reduced steatosis and hepatic inflamamation. RNA-seq identified several metabolic pathways that were influenced by PLD2 deficiency.

Significance: Our data demonstrate that PLD2 is a novel regulator of ALD and suggest that small-molecule PLD2 inhibitors can be considered as a reasonable strategy for ALD treatment.

Keywords: Alcoholic liver disease; Ethanol; Hepatocytes; Phospholipase D2.