摘要：SummaryActivation of resident macrophages (Mϕ) and hepatic stellate cells is a key event in chronic liver injury. Mice with heme oxygenase-1 (HO-1;Hmox1)-deficient Mϕ (LysM-Cre:Hmox1flfl)exhibit increased inflammation, periportal ductular reaction, and liver fibrosis following bile duct ligation (BDL)-induced liver injury and increased pericellular fibrosis in NASH model.RiboTag-based RNA-sequencing profiling of hepatic HO-1-deficient Mϕ revealed dysregulation of multiple genes involved in lipid and amino acid metabolism, regulation of oxidative stress, and extracellular matrix turnover. Among these genes, ligand of numb-protein X1 (LNX1) expression is strongly suppressed in HO-1-deficient Mϕ. Importantly, HO-1 and LNX1 were expressed by hepatic Mϕ in human biliary and nonbiliary end-stage cirrhosis. We found that Notch1 expression, a downstream target of LNX1, was increased inLysM-Cre:Hmox1flflmice. In HO-1-deficient Mϕ treated with heme, transient overexpression ofLNX1drives M2-like Mϕ polarization. In summary, we identified LNX1/Notch1 pathway as a downstream target of HO-1 in liver fibrosis.Graphical abstractDisplay OmittedHighlights•Deletion of HO-1 in myeloid cells promotes liver injury and fibrosis•HO-1 supports M2-like polarization of macrophages in the liver•HO-1 modulates Notch1 signaling through ligand of numb-protein X1 (LNX1)Biological sciences; Human physiology; Cell biology; Stem cells research
