Claudin-1 is a mediator and therapeutic target in primary sclerosing cholangitis

Primary sclerosing cholangitis (PSC) is a chronic fibrosing cholangiopathy with limited therapeutic options. We identified the cell surface protein Claudin-1 as a key mediator and potential therapeutic target for PSC. In patients, Claudin-1 expression correlates with disease stage and clinical outcomes. Conditional liver epithelial-specific Claudin-1 knockout in mice reduced liver injury, fibrosis, and cholestasis. Monoclonal antibodies targeting Claudin-1 inhibited fibrosis, cholestasis, and the ductular reaction across advanced PSC mouse models by suppressing pro-inflammatory and fibrogenic signaling. These preclinical findings support the clinical development of Claudin-1-specific antibodies for PSC treatment and have significant implications for physicians, researchers, and drug developers in the field of biliary disease.