A novel technique for hepatic progenitor cell isolation from normal adult rat livers

The transplantation of hepatic progenitor cells (HPCs) is a promising alternate approach to liver transplantation for patients with end-stage liver disease. Here, we report a novel technique for HPCs isolation from normal adult rat livers (no preexposure to chemicals and no injury). HPCs were isolated from normal adult rat livers using a novel four-step collagenase perfusion method followed by density gradient centrifugation. The phenotypic properties of HPCs were characterized by morphological observation, reverse-transcription polymerase chain reaction (RT-PCR), and immunocytochemistry. The results showed that HPCs formed loose colonies and possessed a round or oval shape at culture day 3. These cells proliferated slowly and exhibited progenitor-like characteristics during the 30-day culture period. RT-PCR analysis indicated that the cultured cells were positive for several HPC-specific genes, such as albumin (ALB), alpha-fetoprotein (AFP), cytokeratin 18 (CK18), cytokeratin 19 (CK19), CD45, hepatocyte nuclear factor 1-alpha (HNF-1α), hepatocyte nuclear factor 4-alpha (HNF-4α), and Thy-1. Immunocytochemical staining showed that these cells were consistently positive for ALB, AFP, CK18, CK19, Thy-1, and OV-6. HPCs can be isolated from normal adult rat livers using a simple and effective technique involving four-step collagenase perfusion, further confirming their potential as a strong candidate for hepatocyte therapy.