Human liver organoids model progressive inflammatory and fibrotic injury in non-alcoholic fatty liver disease

Abstract: Chronic liver injury promotes inflammation, which can progress to fibrosis and cirrhosis, a major cause of mortality. Resolving the transcriptional changes orchestrating this transformation remains challenging. Here, we derive single-cell transcriptomic maps of progressive liver injury in human pluripotent stem cell (hPSC) - derived liver organoids (HLOs), modeling steatohepatitis with palmitic acid and fibrosis through TGF-β1 treatment. We observe that palmitic acid drives inflammation and non-alcoholic fatty liver disease (NAFLD) expression signatures, while TGF-β1 expands hepatic stellate-like populations, remodels cell cycle patterning, and induces extracellular matrix pathways. Analysis of receptor-ligand expression defines the induction of genes regulating Notch and fatty acid signaling with palmitic acid treatment, while the TGF-β1 response is shaped by the co-expression of COL1A1 and integrins to promote crosstalk between hepatocytes, cholangiocytes, and stellate cells. Finally, inflamed and fibrotic HLOs sequentially induce genes predicting disease progression in NAFLD. Our findings highlight HLOs as dynamic human in vitro systems to study evolving liver injury, providing a single-cell transcriptomic reference that will facilitate benchmarking future organoid-based liver injury models.