Hepatocyte-derived extracellular vesicles promote endothelial dedifferentiation in chronic liver disease through the miR-153-3p - pyroptosis axis.

Background Aims
Liver cells communicate paracrinally through extracellular vesicles (EVs). This study investigated the role of miRNAs embedded in hepatocyte derived EVs (hepEVs) modulating endothelial cell dedifferentiation in chronic liver disease.
Methods
EVs were purified from primary hepatocytes isolated from healthy (CT) and cirrhotic (CH) livers in both humans and rats. CT-rats were intravenously treated with fluorescence-labelled hepEVs-CT or hepEVs-CH (200 μg/d, 3 d, n=10/group) to assess biodistribution and liver sinusoidal endothelial cells (LSECs) phenotype. miRNA profiling of human hepEVs-CH was validated in rat models, and commonly altered miRNAs were over-expressed in CT-LSECs. Gene dysregulation was analysed in primary CH-LSECs and liver tissues from rats and humans with cirrhosis, as well as CT-LSECs treated with miRNA-specific upregulated hepEVs. CH-rats were treated with the Caspase-1 inhibitor VX-765 (15 mg/kg/d, 10 doses, n=11/group) to evaluate its effects on liver function, haemodynamics, and endothelial phenotype.
Results
In vivo, hepEVs-CH accumulated predominantly in LSECs, disrupting genes involved in fibrosis, inflammation and cell death, while enhancing vWF expression and altering eNOS activity. Profiling of human hepEVs-CH revealed 37 dysregulated miRNAs, with miR-200a-3p and miR-153-3p validated in rat hepEVs-CH. Transfection of miR-153-3p into CT-LSEC dysregulated 771 genes involved in inflammation and cell death, particularly pyroptosis. Increased active Caspase-1 and Gasdermin-D expression was observed in human and rat cirrhotic liver tissue, as well as in CT-LSEC treated with miR-153-3p-hepEVs, indicating enhanced pyroptosis. In vivo, VX-765 treatment reduced hepatic pyroptosis, improving endothelial phenotype and portal hypertension.
Conclusions
HepEVs-derived miRNAs, particularly miR-153-3p, contribute to endothelial dysfunction in CLD by triggering pyroptosis through a paracrine mechanism. Inhibiting Caspase-1 may provide a novel therapeutic approach to mitigate endothelial dysfunction in CLD.