Isolation, characterization, and transplantation of adult liver progenitor cells.

Many chronic liver diseases are life-threatening. When the liver loses the ability to repair itself the only treatment currently available is liver transplant. However, there are not enough donors to treat all the patients. This requires the search of alternative therapies utilizing stem and progenitor cells for treatment of these patients and restoration of their normal liver function.Hepatic progenitor cells can be isolated from livers at different developmental stages including adult liver. In the adult rat liver, there is clear evidence that progenitor cells (also called "oval cells") derive from precursors in the canals of Herring that are capable to differentiate into hepatocytes and bile duct cells. In experimental models, hepatic progenitor cells can be isolated and propagated in vitro and used for restoration of the diseased liver. The first step in utilization of progenitor cells is their identification in the liver, isolation of purified progenitor cell fractions, which are subsequently transplanted in the diseased liver for evaluation of liver repopulation by transplanted cells, and evaluation their potentials for clinical application.The present protocol describes the isolation of non-parenchymal cells (NPCs) from wt DPPIV(+) F344 rats, followed by purification of "oval cells", immunohistochemical staining techniques to characterize these cells, their transplantation into retrorsine-treated mutant DPPIV(-) rats, as well as the enzyme histochemical staining for DPPIV to detect transplanted cells in the host liver.