The phenotype of hepatocytes has been thought to be fixed once they are terminally differentiated. However, we and other investigators have demonstrated that mature hepatocytes can transform into bile duct/ductule cells in various experimental conditions in vitro. Since the normal bile duct system is almost invariably surrounded by dense periportal collagenous matrices, we placed isolated hepatocytes in a collagen-rich environment to address whether mature hepatocytes can transform into ductular cells. Here, we describe in detail our three-dimensional collagen culture method for the induction of transdifferentiation of mature rat hepatocytes into bile ductular cells. Our in vitro system might be useful for the elucidation of the mechanisms of the aberrant differentiation of hepatocytes in the diseased liver.
