The first demonstrating of a functional human organ (i.e. liver) generated from pluripotent stem cells has been recently reported in Nature. Specified hepatic cells (immature endodermal cells destined to track the hepatic cell fate), endothelial cells and mesenchymal cells self-organized into three-dimensional liver buds in vitro that were transplanted in recipient mice. The vasculature of liver bud transplants became functional by connecting to the host vessels within 48 hours. The formation of functional vasculatures stimulated the maturation of liver buds into tissue resembling the adult liver. The transplanted liver tissue performed liver-specific functions such as protein production and human-specific drug metabolism without recipient liver replacement. Furthermore, transplantation of such liver buds rescued the drug-induced lethal liver failure model. This proof-of-concept demonstration of organ-bud transplantation provides a promising approach for regenerative medicine.
Posted by Nicola Brunetti-Pierri, MD