Open AccessHepatic stem cells: from inside and outside the liver?
Author(s) -
Alison M. R.,
Vig P.,
Russo F.,
Bigger B. W.,
Amofah E.,
Themis M.,
Forbes S.
Publication year - 2004
Publication title -
cell proliferation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.647
H-Index - 74
eISSN - 1365-2184
pISSN - 0960-7722
DOI - 10.1111/j.1365-2184.2004.00297.x
Subject(s) - stem cell , biology , transdifferentiation , haematopoiesis , liver regeneration , hepatocyte , microbiology and biotechnology , liver cytology , regeneration (biology) , population , adult stem cell , bone marrow , immunology , cellular differentiation , medicine , endocrinology , liver metabolism , genetics , environmental health , in vitro , gene
. The liver is normally proliferatively quiescent, but hepatocyte loss through partial hepatectomy, uncomplicated by virus infection or inflammation, invokes a rapid regenerative response from all cell types in the liver to perfectly restore liver mass. Moreover, hepatocyte transplants in animals have shown that a certain proportion of hepatocytes in foetal and adult liver can clonally expand, suggesting that hepatoblasts/hepatocytes are themselves the functional stem cells of the liver. More severe liver injury can activate a potential stem cell compartment located within the intrahepatic biliary tree, giving rise to cords of bipotential transit amplifying cells (oval cells), that can ultimately differentiate into hepatocytes and biliary epithelial cells. A third population of stem cells with hepatic potential resides in the bone marrow; these haematopoietic stem cells may contribute to the albeit low renewal rate of hepatocytes, but can make a more significant contribution to regeneration under a very strong positive selection pressure. In such instances, cell fusion rather than transdifferentiation appears to be the underlying mechanism by which the haematopoietic genome becomes reprogrammed.