ABSTRACT
The liver has a comparatively high regenerative ability. Resident hepatic progenitor cells exist in liver, and the regenerative capacity is increased by a stimulus such as partial hepatectomy (Kuwahara et al. 2008). In addition, hepatic injury induces the mobilization of bone marrow-derived HSCs (Lemoli et al. 2006), which support the liver regeneration by enhancing vascular remodeling, macrophage-led matrix remodeling, and immune modulation (Stutchfi eld et al. 2010). However, severe liver injury requires more than what the resident stem cell can provide. The only cure for terminally ill patients of cirrhosis or hepatic carcinoma is an orthotopic liver transplant. Human hepatocyte transplantation is considered as an alternative to the liver transplantation. But, the limited supply of primary human hepatocytes has necessitated the pursuit of other sources. Transplantation of fetal liver precursor cells has been also studied for regeneration of the liver, but effi cient liver regeneration was not observed (Haridass et al. 2009). MSCs can also differentiate into hepatocyte-like cells (Ikeda et al. 2008, Zheng et al. 2008). Mobilization and harvest of autologous bone marrow-derived stem cells by granulocyte colony stimulating factor (G-CSF) are actively studied as a promising cell candidate to prevent immune rejection and support damaged liver tissue (Stutchfi eld et al. 2010). However, MSCs contribute to the liver fi brosis, rendering MSCs not an ideal cell type for liver regeneration (Russo et al. 2006).
