Leukemia inhibitory factor promotes human cholangiopathies, and its inhibition improves cholestasis in Abcb4-/- mice.

Background: Primary sclerosing cholangitis (PSC) and primary biliary cholangitis (PBC) are immune-mediated cholestatic disorders characterized by progressive biliary inflammation and fibrosis, for which treatment options remain limited, underscoring the need for novel therapeutic targets. The leukemia inhibitory factor (LIF) is an IL-6-related cytokine that dysregulates the communication between epithelial cells and extracellular matrices by binding a heterodimeric complex formed by LIF receptor (LIFR) and gp130. The role of the LIF/LIFR system in PSC and PBC and its potential as a therapeutic target remain unclear.

Methods: We investigated LIF/LIFR system alteration in PSC and PBC and assessed the therapeutic potential of LIFR antagonism in a genetic mouse model of PSC (Abcb4-/- mice). Single-cell transcriptomics analyses were performed to evaluate LIF and LIFR expression in human liver samples. Whole liver RNA-seq and immunostaining were used to assess LIF/LIFR levels and correlation with fibrotic and immune markers. The effects of LIFR antagonism were evaluated in vitro using LRI-310, a steroidal LIFR antagonist, on human cholangiocytes, HSCs, endothelial cells, and macrophages. In vivo, LRI-310 was administered to Abcb4-/- mice, and effects on liver injury, cholestasis, fibrosis, leukocyte infiltration, and gene expression were assessed.

Results: LIF expression s enriched in human cholangiocytes, while LIFR is predominantly expressed by HSCs, endothelial cells, and macrophages. Whole liver RNAseq analysis and liver sections immunostaining demonstarted that increased LIF expression correlates with expression of markers of hepatic fibrosis and immune activation in PSC and PBC patients. LRI-310, a steroidal LIFR antagonist, attenuated human cholangiocytes activation and expression of inflammatory mediators, as well as the activation of liver sinusoidal cells and hepatic fibroblasts. In Abcb4-/- mice administration of LRI-310 mitigated liver injury, cholestasis, liver leukocytes infiltration and reduced the expression of biomarkers associated with fibrosis, inflammation, and bile acid dismetabolism.

Conclusion: Cholangiocyte-derived LIF promotes the formation of a pro-inflammatory and pro-fibrotic niche centred on damaged cholangiocytes. LIFR antagonism reverses fibrosis and immune dysregulation in Abcb4-/- mice, supporting the development of anti-LIFR therapies in human cholangiopathies.