Novel Mechanistic Insights into Primary Biliary Cholangitis: From Pathogenesis to Mesenchymal Stem Cell-Mediated Repair.

Primary biliary cholangitis (PBC) is an autoimmune-mediated cholestatic liver disease characterized by the progressive destruction of intrahepatic bile ducts, which ultimately leads to hepatic fibrosis and cirrhosis. The current first-line therapy, ursodeoxycholic acid, is associated with a high rate of non-response. Moreover, second-line treatments are constrained by variable efficacy and safety concerns. Mesenchymal stem cells (MSCs), owing to their potent immunomodulatory and tissue-repairing capabilities, represent a promising new therapeutic strategy for PBC patients with poor response to conventional therapies. This review systematically outlines the pathogenesis of PBC, focusing on factors including genetics, environment, and immune dysregulation. Furthermore, it examines recent evidence on the mechanisms by which MSCs and their derivatives, such as exosomes, may intervene in PBC progression through immunomodulation, anti-fibrotic effects, and potential hepatic differentiation. This paper also reviews the current status and challenges of the clinical translation of MSCs therapy, and proposes that engineered modification and standardized preparation are the key directions to promote its application. In conclusion, this review provides a theoretical foundation and future directions for deepening the understanding of PBC pathogenesis and developing novel MSC-based therapeutic strategies.