Human Hepatic Progenitor Cells in Hepatic Fibrosis of Elderly Cadavers: Cytokeratin 7 Marks Intermediate Hepatocyte-Like Cells

Human hepatic progenitor cells (HPCs) are small oval-shaped cytokeratin (CK) 7 and CK19 expressing cells that normally reside in a quiescent state in the canals of Hering. In response to liver damage, as in alcoholic liver disease, nonalcoholic fatty liver disease, viral hepatitis, and chronic cholestasis, the HPCs become activated. Being bipotential cells, HPCs can differentiate into either cholangiocytes or hepatocytes; the latter occurs via intermediate hepatocyte-like cells (IHLCs). IHLCs are polygonal in shape with a size intermediate between HPCs and hepatocytes and express phenotypic markers for biliary lineage and hepatocytic lineage. It has been reported in baboons chronically fed alcohol that an increased number of CK7 immunoreactive IHLCs correlated with the progression to more severe stages of liver fibrosis; CK19 immunoreactive IHLCs, however, were not observed. Since elderly cadavers with diverse causes of death demonstrated progressive stages of liver fibrosis (Mak et al., 2012, Anat Rec 29...