Differentiation of a hepatic phenotype after heterotropic transplantation of heart, kidney, brain, and skin tissues into liver in F344 rats

While organ-specific stem cells with roles in tissue injury repair have been documented, their pathogenic significance in diseases and the factors potentially responsible for their activation remain largely unclear. In the present study, heart, kidney, brain, and skin samples from F344 transgenic rats carrying the GFP gene were transplanted into normal F344 rat liver one day after an intraperitoneal injection (i.p.) of carbon tetrachloride (CCl4) to test their differentiation capacity. The transplantation was carried out by female donors to male recipients, and vice versa. One week after transplantation, GFP antigen-positive cells with phenotypic characteristics of hepatocytes were noted. After two weeks, their extent increased, and at 4 weeks, large areas of strongly GFP-stained cells developed. All recipient livers had GFP antigen-positive hepatocyte cells. PCR analysis coupled with laser capture micro-dissection (LCM) revealed those cells to contain GFP DNA. Thus, our results indicate that tissue stem cells have multipotential ability, differentiating into hepatocytes when transplanted into an injured liver.