Establishment and characterization of atypical fibroblasts from human adult liver contributing to hepatocyte cord-like arrangement

We report the phenotypic and functional characterization of fibroblasts established in culture from the non-parenchymal epithelial cell populations of adult human livers. Human liver fibroblasts (hLF) expressed mesenchymal antigens vimentin, alpha-smooth muscle actin, collagen, fibronectin, CD73, CD90, CD105, and CD166 together with non-mesenchymal antigens cytokeratins 8 and 18, glial fibrillary acidic protein, and nestin. Mixed cell lineage-specific protein expression was not associated with stem-like cell properties. Coculturing hepatocytes onto confluent hLF showed that they survived and maintained metabolic activity such as albumin, glycogen, and urea production. Moreover, hepatocytes formed cord-like arrangements resembling those established in vivo. Hepatocyte arrangement depended on cell-to-cell contact and the tissue origin of fibroblasts. Time-lapse video imaging of cocultured cells showed that hepatocyte arrangement was coordinated by the stretching and shortening of underneath hLF. Our data suggest that hLF may represent resident fibroblasts of the adult human liver, which could assume guiding functions for hepatic epithelial cells.