Cell-derived Hepatocyte-like Cells Research Articles

Development of a method of passaging and freezing human iPS cell-derived hepatocytes to improve their functions.

Human induced pluripotent stem (iPS) cell-derived hepatocyte-like cells (HLCs) are expected to replace primary human hepatocytes as a new source of functional hepatocytes in various medical applications. However, the hepatic functions of HLCs are still low and it takes a long time to differentiate them from human iPS cells. Furthermore, HLCs have very low proliferative capacity and are difficult to be passaged due to loss of hepatic functions after reseeding. To overcome these problems, we attempted to develop a technology to dissociate, cryopreserve, and reseed HLCs in this study. By adding epithelial-mesenchymal transition inhibitors and optimizing the cell dissociation time, we have developed a method for passaging HLCs without loss of their functions. After passage, HLCs showed a hepatocyte-like polygonal cell morphology and expressed major hepatocyte marker proteins such as albumin and cytochrome P450 3A4 (CYP3A4). In addition, the HLCs had low-density lipoprotein uptake and glycogen storage capacity. The HLCs also showed higher CYP3A4 activity and increased gene expression levels of major hepatocyte markers after passage compared to before passage. Finally, they maintained their functions even after their cryopreservation and re-culture. By applying this technology, it will be possible to provide ready-to-use availability of cryopreserved HLCs for drug discovery research.

Generation of Zone-specific Hepatocyte-like Cells from Human Induced Pluripotent Stem Cells for Accurate Prediction of Drug-induced Hepatotoxicity

Human induced pluripotent stem (iPS) cell-derived hepatocyte-like cells (iPS-HLCs) are expected to be applicable to large-scale in vitro hepatotoxicity screening systems. Accordingly, methods for generating HLCs from human iPS cells have been improved over the past decade. However, although human hepatocytes have zone-specific characteristics in vivo, there is currently no technique to generate zone-specific HLCs from human iPS cells. Therefore, to generate HLCs with zone-specific properties from human iPS cells, we cultured iPS-HLCs using a parenchymal or nonparenchymal cell-conditioned medium (CM). The results showed that urea production and gluconeogenesis capacity in iPS-HLCs were increased by culturing with cholangiocyte-CM, and glutamine production and drug metabolism capacity in iPS-HLCs were increased by culturing with hepatocyte-CM. It was thus clarified that iPS-HLCs acquire zone 1 hepatocyte-like properties by culturing with cholangiocyte-CM and that iPS-HLCs acquire zone 3 hepatocyte-like properties by culturing with hepatocyte-CM. In addition, we found that WNT inhibitory factor-1 secreted from cholangiocytes, and WNT7B and WNT8B secreted from hepatocytes play important roles in the zone-specific conversion of iPS-HLCs. We hope that our findings will facilitate the application of iPS-HLCs to drug discovery research.

Therapeutic efficiency of human amniotic epithelial stem cell-derived functional hepatocyte-like cells in mice with acute hepatic failure

BackgroundHepatocyte transplantation has been proposed as an effective treatment for patients with acute liver failure (ALF), but its application is limited by a severe shortage of donor livers. Human pluripotent stem cells (hPSCs) have emerged as a potential cell source for regenerative medicine. Human amniotic epithelial stem cells (hAESCs) derived from amniotic membrane have multilineage differentiation potential which makes them suitable for possible application in hepatocyte regeneration and ALF treatment.MethodsThe pluripotent characteristics, immunogenicity, and tumorigenicity of hAESCs were studied by various methods. hAESCs were differentiated to hepatocyte-like cells (HLCs) using a non-transgenic and three-step induction protocol. ALB secretion, urea production, periodic acid-Schiff staining, and ICG uptake were performed to investigate the function of HLCs. The HLCs were transplanted into ALF NOD-SCID (nonobese diabetic severe combined immunodeficient) mouse, and the therapeutic effects were determined via liver function test, histopathology, and survival rate analysis. The ability of HLCs to engraft the damaged liver was evaluated by detecting the presence of GFP-positive cells.ResultshAESCs expressed various markers of embryonic stem cells, epithelial stem cells, and mesenchymal stem cells and have low immunogenicity and no tumorigenicity. hAESC-derived hepatocytes possess the similar functions of human primary hepatocytes (hPH) such as producing urea, secreting ALB, uptaking ICG, storing glycogen, and expressing CYP enzymes. HLC transplantation via the tail vein could engraft in live parenchymal, improve the liver function, and protect hepatic injury from CCl4-induced ALF in mice. More importantly, HLC transplantation was able to significantly prolong the survival of ALF mouse.ConclusionWe have established a rapid and efficient differentiation protocol that is able to successfully generate ample functional HLCs from hAESCs, in which the liver injuries and death rate of CCl4-induced ALF mouse can be significantly rescued by HLC transplantation. Therefore, our results may offer a superior approach for treating ALF.

Billion-scale production of hepatocyte-like cells from human induced pluripotent stem cells

Human induced pluripotent stem (iPS) cell-derived hepatocyte-like cells are expected to be utilized in drug screening and regenerative medicine. However, hepatocyte-like cells have not been fully used in such applications because it is difficult to produce such cells on a large scale. In this study, we tried to establish a method to mass produce hepatocyte-like cells using a three-dimensional (3D) cell culture bioreactor called the Rotary Cell Culture System (RCCS). RCCS enabled us to obtain homogenous hepatocyte-like cells on a billion scale (>109 cells). The gene expression levels of some hepatocyte markers (alpha-1 antitrypsin, cytochrome (CYP) 1A2, CYP2D6, and hepatocyte nuclear factor 4alpha) were higher in 3D-cultured hepatocyte-like cells than in 2D-cultured hepatocyte-like cells. This result suggests that RCCS could provide more suitable conditions for hepatocyte maturation than the conventional 2D cell culture conditions. In addition, more than 90% of hepatocyte-like cells were positive for albumin and could uptake low-density lipoprotein in the culture medium. We succeeded in the large-scale production of homogenous and functional hepatocyte-like cells from human iPS cells. This technology will be useful in drug screening and regenerative medicine, which require enormous numbers of hepatocyte-like cells.