Gallbladder epithelial cells that engraft in mouse liver can differentiate into hepatocyte-like cells

We tested the hypothesis that well-differentiated gallbladder epithelial cells (GBECs) are capable of engrafting and surviving in murine liver and acquire phenotypic characteristics of hepatocytes. GBECs isolated from transgenic mice that constitutively express green fluorescent protein (GFP) were either cultured before transplantation or transplanted immediately following isolation. Recipient mice with severe-combined immunodeficiency underwent retrorsine treatment and either partial hepatectomy before transplantation or carbon tetrachloride treatment following transplantation. From 1 to 4 months following transplantation, the livers of recipient mice contained discrete colonies of GFP(+) cells. Most GFP(+) cells surrounded vesicles, were epithelial cell-like in morphology, and expressed the biliary epithelial markers cytokeratin 19 and carbonic anhydrase IV. Subpopulations of GFP(+) cells resembled hepatocytes morphologically and expressed the hepatocyte-specific markers connexin-32 and hepatic nuclear factor-4alpha, but not cytokeratin 19 or carbonic anhydrase IV. At 4 months, cells in GFP(+) colonies were not actively proliferating as determined by proliferating cell nuclear antigen expression. Thus, GBECs are capable of engrafting and surviving in damaged mouse livers, and some can differentiate into cells with hepatocyte-like features. These findings suggest that environmental cues in the recipient liver are sufficient to allow a subpopulation of donor GBECs to differentiate into hepatocyte-like cells in the absence of exogenous transcriptional reprogramming. GBECs might be used as donor cells in a cell transplantation approach for the treatment of liver disease.