MH designed and performed experiments and interpreted results.. L.A. designed and performed the in vitro experiments, M.A.M., designed and performed the in vivo experiments, L.C-E., the hydroxymethylation and EdU stainings, G.B, experiments with small molecule inhibitors. G.V. and E.A.M. prepared and analysed WGBS and RRHP libraries, analysed RNAseq and interpreted corresponding bionformatic analyses related. N.A., A.R. and S.J.F. performed experiments with β1 integrin model and interpreted results of the p21 models. J.v.d.A. and A.H.B. performed DamID-seq experiments. B.F-C helped on the in vivo analysis. R.A.C. helped on bioinformatics analyses. R.L.M. provided the R26Fucci2a line. F.A. and M.Z.G. performed the live imaging of ductal cells.

BMDMs Phagocytosis Necrotic hepatocytes Proinflammatory cytokines Crosstalk with innate immune system AAMs Infiltrating neutrophils +IL-4 +IL-13 Endothelial cell proliferation Growth factors Central vein Highlights Primary BMDMs localised to liver and spleen within hours following intravenous injection in mice. AAMs were highly phagocytic and i.v. transfer elicited reductions in necrotic area, HMGB1 translocation, and hepatic neutrophil infiltration. AAM injection reduced inflammatory mediators and stimulated hepatocyte/endothelium proliferation in injured liver. Injection of clinical-grade human AAMs could partially recapitulate the efficacy of murine AAMs in immunocompetent mice.

Following injury, the liver's epithelial cells regenerate efficiently with rapid proliferation of hepatocytes and biliary cells. However, when proliferation of resident epithelial cells is impaired, alternative regeneration mechanisms can occur. Intricate lineage-tracing strategies and experimental models of regenerative stress have revealed a degree of plasticity between hepatocytes and biliary cells. New technologies such as singlecell omics, in combination with functional studies, will be instrumental to uncover the remaining unknowns in the field. In this review, we evaluate the experimental and clinical evidence for epithelial plasticity in the liver and how this influences the development of therapeutic strategies for chronic liver disease. ll