P0988 - The fibrogenic injury of liver ductal organoids is rescued by human amniotic fluid stem cells

Purpose: Liver fibrosis is a wound healing process resulting from chronic liver injury which can progress to liver cirrhosis and end-staged liver disease. Cholangiocyte apoptosis has influence on the pathogenesis of cholangiopathic diseases and may play role in their liver fibrogenesis process. Human amniotic fluid stem cells (hAFSCs) are multipotent cells which have the potential to inhibit cell apoptosis. This study aimed to investigate whether hAFSCs possess anti-fibrogenic effect in an injury-induced fibrogenesis of liver ductal organoids.

Methods: Following ethical approval (#47780), liver ductal organoids were generated from intrahepatic bile duct of healthy neonatal mice. These organoids are composed of cholangiocytes which can differentiate into functional hepatocytes. hAFSCs were co-cultured with liver ductal organoids in Matrigel for 4 days before induced injury for 24 hours by administration of acetaminophen, a hepatotoxic agent. mRNA expression levels of fibrogenic cytokines were analyzed by RT-qPCR. Cell apoptosis and proliferation markers were evaluated by immunofluorescent staining. Data were compared using one-way ANOVA with Bonferroni correction.

Results: After injury, the organoids increased mRNA expression of transforming growth factor beta-1 (TGF-β1) and platelet-derived growth factor-BB (PDGF-BB), the potent cytokines that can stimulate liver fibrogenesis. Co-culture of the organoids with hAFSCs significantly decreased the expressions of these cytokines (Fig A). This fibrogenic injury was associated with increased cholangiocyte apoptosis, which was prevented by administration of amniotic fluid stem cells (Fig B). Moreover, hAFSCs increased cholangiocyte proliferation in injured organoids (Fig B).

Conclusion: In liver ductal organoids, injured cholangiocytes play a role in fibrogenesis by secreting fibrogenic cytokines. hAFSCs protect bile duct from injury by decreasing cholangiocyte apoptosis and promoting cholangiocyte proliferation, and this protective ability lead to inhibition of fibrogenic cytokine secreting. hAFSCs have an important therapeutic potential for treating liver fibrosis in diseases that involve bile duct injury such as biliary atresia.