Human Placental Mesenchymal Stem Cells Relieve Primary Sclerosing Cholangitis via Upregulation of TGR5 in Mdr2^(-/-)Mice and Human Intrahepatic Cholangiocyte Organoid Models

Primary sclerosing cholangitis(PSC)is a biliary disease accompanied by chronic inflammation of the liver and biliary stricture.Mesenchymal stem cells(MSCs)are used to treat liver diseases because of their immune regulation and regeneration-promoting functions.This study was performed to explore the therapeutic potential of human placental MSCs(hP-MSCs)in PSC through the Takeda G protein-coupled receptor 5(TGR5)receptor pathway.Liver tissues were collected from patients with PSC and healthy donors(n=4)for RNA sequencing and intrahepatic cholangiocyte organoid construction.hP-MSCs were injected via the tail vein into Mdr2^(-/-),bile duct ligation(BDL),and 3,5-diethoxycarbonyl-1,4-dihydrocollidine(DDC)mouse models or co-cultured with organoids to confirm their therapeutic effect on biliary cholangitis.Changes in bile acid metabolic profile were analyzed by liquid chromatography/tandem mass spectrometry(LC-MS/MS).Compared with healthy controls,liver tissues and intrahepatic cholangiocyte organoids from PSC patients were characterized by inflammation and cholestasis,and marked downregulation of bile acid receptor TGR5 expression.hP-MSC treatment apparently reduced the inflammation,cholestasis,and fibrosis in Mdr2^(-/-),BDL,and DDC model mice.By activating the phosphatidylinositol 3 kinase/extracellular signal-regulated protein kinase pathway,hP-MSC treatment promoted the proliferation of cholangiocytes,and affected the transcription of downstream nuclear factorκB through regulation of the binding of TGR5 and Pellino3,thereby affecting the cholangiocyte inflammatory phenotype.