Tissue-specific stem cells from differentiating embryonic stem (ES) cells are both pluripotent and genetically flexible. Recent observations indicate that ES cells can differentiate into hepatocytes. Therefore, cell-based therapy can potentially be a therapeutic alternative to liver transplantation. In this study the treatment of acute liver failure in rats by transplantation of hepatocyte nuclear factor 4 (HNF4)-overexpressing ES cells was investigated.METHODS
The HNF4 was transfected into ES cells and ES cell clones overexpressing HNF4 were selected. The levels of markers of hepatocyte differentiation, including albumin, transthyretin, glucose-6-phosphates (G-6-P) and SAPK/ERK kinase-1 (SEK1) mRNA, were tested in spontaneously differentiated HNF4-overexpressing ES cells by reverse transcription-polymerase chain reaction (RT-PCR). The ultrastructure of the spontaneously differentiated HNF4-overexpressing ES cells was examined by electron microscopy. To induce acute liver failure, Sprague–Dawley rats were subjected to 90% hepatectomy and given 5% oral dextrose. The rats were divided into three groups. The rats in the treatment group (n = 12) received intraliver injection of 2 × 107 undifferentiated HNF4-overexpressing ES cells from the same clone, the rats in control group 1 (n = 12) received 2 × 107 undifferentiated ES cells, and the rats in control group 2 (n = 12) received the same volume of media without any cells.RESULTS
All rats in control group 1 and control group 2 died within 72 h, while 33% of rats that received undifferentiated HNF4-overexpressing ES cells transplantation survived more than 1 month. Spontaneously differentiated HNF4-overexpressing ES cells only expressed transthyretin mRNA. The cells were rich in mitochondrion and catalase-containing peroxisomes in ultrastructure.CONCLUSIONS
Transplantation of ES cells could be a potential treatment in supporting life during acute liver insufficiency and could be a bridge to orthotopic liver transplantation.