Alcohol-induced KDM5B activation in hepatocytes drives pathogenic cell-cell communication, leading to loss of liver function.

BACKGROUND: Alcohol-associated liver disease (ALD) is a major cause of alcohol-associated mortality. Previously, we identified KDM5B as a sex-specific mediator of ALD development; however, the mechanism behind KDM5B-induced pathological changes is not established. METHODS: Kdm5b flox/flox female mice were fed a western diet and 20% alcohol in the drinking water for 8-16 weeks (WDA). To induce KO, mice received 2×1011 genome copies of AAV8-CMV-Cre, AAV8-TBG-Cre, or AAV8-control. To test the role of myeloid C/EBPβ, Cebpbfl/fl, or Cebpbfl/fl Lyz2-Cre mice were fed WDA for 16 weeks. RESULTS: We found that Kdm5b KO prevented alcohol-induced liver fibrosis and liver inflammation in female mice. These changes were in part mediated by hepatocyte-to-non-parenchymal cell communication changes. KDM5B in hepatocytes promoted pro-inflammatory and pro-fibrotic changes in liver macrophages, endothelial cells, and stellate cells. Moreover, KDM5B promoted alcohol-induced early increase in EpCAM-positive liver progenitors and loss of liver function at later time points of alcohol feeding. We found that loss of liver function was dependent on a hepatocyte-to-macrophage communication feedback loop. KDM5B in hepatocytes inhibited macrophage C/EBPβ expression, which in turn resulted in loss of the mature KCs phenotype and prevented the ability of KCs to support hepatocyte differentiation, ultimately leading to loss of liver synthetic function. CONCLUSIONS: KDM5B activation in hepatocytes drives pathogenic cell-cell communication, leading to alcohol-induced loss of liver function in ALD.