Cellular communication networks in fibrosis: Insights from the MASLD pig model.

BACKGROUND

This research aims to reveal the cellular cross talk in fibrosis liver using transgenic pigs (TG) expressing humanized risk genes (PNPLA3I148M-GIPRdn-hIAPP) as a metabolic dysfunction-associated steatotic liver disease (MASLD) model.

METHODS AND RESULTS

The study uses single-nucleus sequencing to reveal the differentiation and interaction characteristics of various cell populations in the liver during the development of MASLD. After 6 months of high-fat, high-sucrose diet induction, the model pigs exhibited obvious liver pathological features, including fat deposition, inflammatory cell aggregation, fibrosis, and blocked insulin signaling pathways, similar to PNPLA3 rs738409 C>G carriers. Single-nucleus RNA sequencing showed that pigs share a high correlation with human hepatic cell types and zonation. HSCs in TG pigs are more activated, showing enhancing fibrosis-related pathways and declining retinol metabolism. Pseudo-trajectory analysis revealed that over 90% of macrophages in TG liver differentiated to Fate 1 (CD68hi) with higher expression of major histocompatibility complex-II molecules, proinflammatory cytokines, phagosomes, and lysosomal-related genes. Active cell interactions were found between HSCs, endothelial cells, and Fate1 macrophages. Ligand and receptor interactions, including FGF23-FGFR, PDGFs-PDGFRs, EFNA1-EPHRs, and CXCL12-CXCR4/CXCR7, were predicted to involve in hepatic fibrosis in model pigs.

CONCLUSIONS

The transgenic pig model of MASLD exhibits liver pathological features consistent with patients with MASLD. Our data supplemented the mechanism by which PNPLA3 mutations lead to hepatic steatosis, depicted a detailed atlas of hepatic profibrosis cellular network, and provided a reliable large animal model and data reference for MASLD drug development and precision treatment.