Differentiation of human embryonic stem cells along a hepatocyte lineage and its application in liver regeneration

Hepatocyte transplantation and bioartificial liver (BAL) as alternatives to liver transplantation offer the possibility of effective treatment for many inherited and acquired hepatic disorders. Unfortunately, the limited availability of donated livers and the variability of their derived hepatocytes make it difficult to obtain enough viable human hepatocytes for the hepatocyte-based therapies. Embryonic stem cells (ESCs), which could be isolated directly from the blastocyst inner cell mass, have permanent self-renewal capability and developmental pluripotency and therefore might be an ideal cell source in the treatment of hepatic discords. However, differentiation of hESCs into hepatocytes with significant numbers remains a challenge. This review updates our current understanding of differentiation of ESCs into hepatic lineage cells, their future therapeutic uses and problems in liver regeneration. Supported by the National Key Project for Basic Research of China (Grant No. 2005CB522702), State 863 High Technology R&D Project of China (Grant No. 2006AA02A107), and the National Natural Science Foundation of China (Grant No. 30671098)