Technical advances in the development of zonation liver in vitro systems that incorporate localized Wnt activating signals
A Wnt microenvironment sustained by the hepatic central vein is essential for the segregation of liver functions into zones. Current liver culture systems lack localized Wnt cues and as a consequence fail to maintain the hepatocyte functional heterogeneity that is observed in the intact organ. In this study, organoid models and 2D-culture systems were used to identify cellular sources and Wnt presentation methods that could support the future development of zonated liver in vitro systems. Using soluble ligands, we show that primary hepatocyte (PH)-derived organoids but not bile duct (BD)-derived organoids may be used to recapitulate the resting liver. We provide evidence that differentiation of PH-organoids in the presence of Wnt9b and Rspo3 induce pericentral maturation. Finally, we show that immobilization of Rspo3 onto beads in combination with soluble Wnt9b may be a valid strategy to recreate the central vein Wnt microenvironment in vitro.