Purification and characterization of pluripotent hepatic stem cells

Abstract

Stem cells responsible for tissue maintenance and repair are found in a number of organs. Hepatic stem cells assumed to play a key role in liver development and regeneration remain to be well characterized. By combining single-cell-based assays with fluorescence activated cell sorting (FACS), we prospectively identified hepatic stem cells with multilineage differentiation potential and self-renewing capability. These cells could be clonally propagated in culture, where they continuously produced hepatocytes and cholangiocytes as descendants while maintaining primitive stem cells. When cells that expanded in vitro were transplanted into recipient animals, they morphologically and functionally differentiated into hepatocytes and cholangiocytes, with reconstitution of hepatocyte and bile duct structures. Furthermore, these cells differentiated into pancreatic ductal and acinar cells or intestinal epithelial cells when transplanted into pancreas or duodenal wall. Flowcytometric sorting enabled to identify and purify pluripotent hepatic stem cells reside in the developing liver and allowed to clear a further potential for differentiation. Our data demonstrate that manipulation of hepatic stem cells may provide new insight into therapies for diseases of the digestive system.