EVALUATION OF THE DIFFERENTIATION POTENTIAL OF WB-F344 RAT-LIVER EPITHELIAL STEM-LIKE CELLS IN-VIVO - DIFFERENTIATION TO HEPATOCYTES AFTER TRANSPLANTATION INTO DIPEPTIDYLPEPTIDASE-IV-DEFICIENT RAT-LIVER

After intrahepatic transplantation into livers of adult syngeneic Germ an-strain Fischer 344 rats that are deficient for the bile canalicular enzyme dipeptidyl peptidase TV (DPP-IV), cultured WB-F344 rat liver e pithelial cells (without exogenous marker genes) integrate into hepati c plates and differentiate into hepatocyte-like cells that are morphol ogically and functionally indistinguishable from mature hepatocytes, I n this model system, the differentiated progeny of transplanted WB-F34 4 cells are identified among the DPP-IV-negative host hepatocytes by t heir expression of bile canalicular DPP-IV enzyme activity, DPP-IV-pos itive hepatocyte-like cells also expressed other markers of hepatocyti c differentiation, including albumin, transferrin, and alpha-1-antitry psin, suggesting that the progeny of transplanted WB-F344 cells expres s a complete hepatocyte differentiation program, These results complem ent our previous studies indicating WB-F344 cells can serve as stem-li ke precursor cells for differentiated hepatocytes and strengthen the s uggestion that WB-F344 rat Liver epithelial cells represent the cultur ed counterpart of liver stem-like hepatocyte progenitor cells present in the normal adult rat liver.