Differentiation of rat multipotent adult progenitor cells to functional hepatocyte-like cells by mimicking embryonic liver development.

Differentiation of stem cells to hepatocytes has industrial applications, as well as the potential to develop new therapeutic strategies for liver disease. The protocol described here, sequentially using cytokines that are known to have a role in liver embryonic development, efficiently differentiates rat multipotent adult progenitor cells (rMAPCs) to hepatocyte-like cells by directing them through defined embryonic intermediates, namely, primitive streak/mesendoderm/definitive endoderm, hepatoblast and hepatocyte-like phenotype. After 20 days, the final differentiated multipotent adult progenitor cell progeny is a mixture of cells, comprising cells with the characteristics of hepatoblasts and a smaller cell fraction with the morphological and phenotypical features of mature hepatocytes, as well as other mesodermal cells and some persistent undifferentiated rMAPCs. A detailed functional characterization of the stem cell progeny is also described; this should be used to confirm that differentiated cells display the functional characteristics of mature hepatocytes, including albumin secretion, glycogen storage and several detoxifying functions such as urea production, bilirubin conjugation, glutathione S-transferase activity and cytochrome activity.