Mincle-GSDMD-mediated release of IL-1β small extracellular vesicles from hepatic macrophages in ethanol-induced liver injury

Hepatol Commun. 2023 Apr 26;7(5):e0114. doi: 10.1097/HC9.0000000000000114. eCollection 2023 May 1.

Abstract

Background: Macrophage-inducible C-type lectin (Mincle) is expressed on hepatic macrophages and senses ethanol (EtOH)-induced danger signals released from dying hepatocytes and promotes IL-1β production. However, it remains unclear what and how EtOH-induced Mincle ligands activate downstream signaling events to mediate IL-1β release and contribute to alcohol-associated liver disease (ALD). In this study, we investigated the association of circulating β-glucosylceramide (β-GluCer), an endogenous Mincle ligand, with severity of ALD and examined the mechanism by which β-GluCer engages Mincle on hepatic macrophages to release IL-1β in the absence of cell death and exacerbates ALD.

Method and results: Concentrations of β-GluCer were increased in serum of patients with severe AH and correlated with disease severity. Challenge of hepatic macrophages with lipopolysaccharide and β-GluCer induced formation of a Mincle and Gsdmd-dependent secretory complex containing chaperoned full-length gasdermin D (Hsp90-CDC37-NEDD4) with polyubiquitinated pro-IL-1β and components of the Caspase 8-NLRP3 inflammasome loaded as cargo in small extracellular vesicles (sEVs). Gao-binge EtOH exposure to wild-type, but not Mincle-/- and Gsdmd-/-, mice increased release of IL-1β-containing sEVs from liver explant cultures. Myeloid-specific deletion of Gsdmd similarly decreased the formation of sEVs by liver explant cultures and protected mice from EtOH-induced liver injury. sEVs collected from EtOH-fed wild-type, but not Gsdmd-/-, mice promoted injury of cultured hepatocytes and, when injected into wild-type mice, aggravated Gao-binge EtOH-induced liver injury.

Conclusion: β-GluCer functions as a danger-associated molecular pattern activating Mincle-dependent gasdermin D-mediated formation and release of IL-1β-containing sEVs, which in turn exacerbate hepatocyte cell death and contribute to the pathogenesis of ALD.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Chemical and Drug Induced Liver Injury, Chronic*
  • Ethanol / toxicity
  • Gasdermins
  • Kupffer Cells / metabolism
  • Liver Diseases, Alcoholic* / metabolism
  • Mice

Substances

  • Ethanol
  • Gasdermins
  • Clecsf8 protein, mouse
  • Gsdmd protein, mouse
  • IL1B protein, mouse