Mitigation of polystyrene microplastic-induced hepatotoxicity in human hepatobiliary organoids through bile extraction

Background & Aims: Polystyrene microplastics (PS-MPs) are pervasive in our daily life and can be ingested by the human body through bioaccumulation, causing organ damage, especially liver damage. However, the effect of PS-MPs bioaccumulation on human hepatotoxicity and their metabolism remains unclear. Recent studies have demonstrated that PS-MPs cause lipid and bile acid metabolism disorders. The human hepatobiliary organoids (HBOs) regenerated from chemically induced liver progenitor cells converted by mature hepatocytes and the bile duct provides a bioengineering model for liver disease and hepatic metabolism. Approach & Results: Exposure of HBOs to PS-MPs with a diameter of 1 µm for 48 h causes hepatotoxicity, hepatocyte damage, and changes in bile acid metabolism. PS-MPs could be accumulated into the bile ducts of HBOs, which can be promoted by ursodeoxycholic acid, increasing bile flow and volume by activating the bile transporter of BSEP in a dose-dependent manner along with MRP-2. The accumulation of PS-MPs in the bile duct was able to be inhibited by the bile transporter inhibitor of troglitazone that could inhibit the transporters of BSEP and MRP-2, which increased the hepatotoxicity caused by PS-MPs. Conclusions: This study provides insights into the metabolic pathways of PS-MPs in the liver and suggests potential therapeutic strategies to reduce MP-induced liver damage.