5D, panel ii). Primary human hepatocytes were used as a positive control (Fig. 5D, panels

iii and iv). To assess the therapeutic potential of iPSC-derived hepatocytes, a model of lethal fulminant hepatic failure caused by CCl4 in NOD-SCID mice was used. A dose of 0.35 mL/kg body weight was optimal and resulted in lethality in all animals in 2 weeks after administration of CCl4. Transplantation of 4.0 × 107 iPSCs per kilogram body weight failed to rescue recipient animals from fulminant hepatic failure (0 of 7 mice survived). However, in mice that received iPSC-derived hepatocyte cells, 71% of the animals were rescued from the transplantation of 4.0 × 107 iPSC-derived hepatocytes per kilogram body weight (5 of 7 mice survived) (Fig. 6A). Histopathologic analysis showed the presence of submassive hepatic necrosis liver in mice (Fig. 6B, panel viii), whereas the hepatic necrosis was rescued by transplantation www.selleckchem.com/products/pembrolizumab.html of iPSC-derived hepatocytes, but not by iPSCs. Biochemical assays showed a dynamic change in the serum levels of hepatic marker proteins such as serum glutamyl oxaloacetic aminotransferase, glutamyl pyruvic aminotransferase, albumin, total bilirubin, and lactate dehydrogenase, confirming the infliction of acute liver failure by CCl4 (Table 2). To investigate whether the transplanted cells were engrafted in liver parenchyma JAK inhibitor of the recipients, two human hepatocyte-specific

markers, HepPar128 and albumin, were used to detect human liver cells in mouse liver. Recipient mice that were rescued by intrasplenic transplantation of iPSC-derived

hepatocytes were sacrificed on day 28 after transplantation. The immunohistochemical staining showed the presence of human HepPar1 and albumin in the liver parenchyma of recipient animals. These data 上海皓元 indicate that the human iPSC-derived hepatocytes had been engrafted in recipient liver parenchyma (Fig. 6C,D). In this study, we developed a novel three-step protocol that efficiently generated hepatocyte-like cells from human iPSCs in vitro. During our differentiation protocol, human iPSCs are exposed to a high level of activin, Nodal, and Wnt signaling in a manner that is designed to mimic events during embryonic development in order to allow definitive endoderm formation.29, 30 This is followed by a hepatic lineage commitment and a maturation step. The results show that we successfully generated iPSC-derived hepatocyte cells that not only express hepatic markers but also have urea production and carry out glycogen storage. Although other methods for the hepatogenic differentiation of human iPSCs have been described, few have shown a close relationship between the iPSC-derived hepatocyte cells and primary human hepatocytes, using microarray gene expression profiling. A comparison of the gene expression profile with that of a previous study17 showed that our differentiated cells had a similar gene profile to the earlier study and that their profile is closely related to primary human hepatocytes.