Kruti Nataraj | PubMed Health

PubMed2025

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.

Animals↗

PubMed2024

Androgen Effects on Alcohol-induced Liver Fibrosis Are Controlled by a Notch-dependent Epigenetic Switch.

BACKGROUND & AIMS: Alcohol-associated liver disease (ALD) is a major cause of alcohol-related mortality. Sex is an important variable; however, the mechanism behind sex differences is not yet established. METHODS: Kdm5b flox/flox Kdm5c flox male mice were subjected to gonadectomy or sham surgery. Mice were fed a Western diet and 20% alcohol in the drinking water for 18 weeks. To induce knockout, mice received 2 × 1011 genome copies of AAV8-CMV-Cre or AAV8-control. To test the role of Notch, mice were treated with 10 mg/kg of avagacestat for 4 weeks. RESULTS: We found that Kdm5b/Kdm5c knockout promoted alcohol-induced liver disease, whereas gonadectomy abolished this effect, suggesting that male sex hormones promote liver disease in the absence of KDM5 demethylases. In contrast, in the thioacetamide-induced fibrosis model, male sex hormones showed a protective effect regardless of genotype. In human liver disease samples, we found that androgen receptor expression positively correlated with fibrosis levels when KDM5B levels were low and negatively when KDM5B was high, suggesting that a KDM5B-dependent epigenetic state defines the androgen receptor role in liver fibrosis. Using isolated cells, we found that this difference was due to the differential effect of testosterone on hepatic stellate cell activation in the absence or presence of KDM5B/KDM5C. Moreover, this effect was mediated by KDM5-dependent suppression of Notch signaling. In KDM5-deficient mice, Notch3 and Jag1 gene expression was induced, facilitating testosterone-mediated induction of Notch signaling and stellate cell activation. Inhibiting Notch with avagacestat greatly reduced liver fibrosis and abolished the effect of Kdm5b/Kdm5c loss. CONCLUSIONS: Male sex hormone signaling can promote or prevent alcohol-associated liver fibrosis depending on the KDM5-dependent epigenetic state.

Animals↗