Human amniotic epithelial cells are promising transgene carriers for allogeneic cell transplantation into liver

As human amniotic epithelial tissue is formed on about the eighth day after fertilization, human amniotic epithelial cells (hAEC) may have multipotenc y to differentiate into various organs, such as brain, heart, or liver. In this study, we showed evidence of the synthesis and excretion of albumin by hAEC, by immunostaining and enzyme-linked immunoassay. Reverse transcripti on-polymerase chain reaction (RT-PCR) and western blot analyses revealed th e expression of albumin mRNA and protein, respectively. In addition, hAEC a lso demonstrated immunoreactivity to genetic markers of liver lineage, such as human serum albumin and alpha-fetoprotein. Transplanted hAEC to Scid mo use liver showed positive immunoreactivity to albumin and alpha-fetoprotein . Genetically modified cells containing the (beta-galactosidase (LacZ) gene (AxCALacZ) were integrated in liver parenchyma. Human polymorphic gene ana lysis in Scid mouse liver after the implantation of hAEC showed that these Scid mouse livers obviously contained this human-specific gene until day 7 after the cell transplantation. As hAEC do not cause any acute rejection by allotransplantation, we conclude that hAEC may be useful as a transgene ca rrier to treat patients with inherited liver diseases.