Project description:The future clinical use of embryonic stem cell (ESC)-based hepatocyte replacement therapy depends on the development of an efficient procedure for differentiation of hepatocyes from ESCs. Here we report that a high density of human embryonic stem cell (ESC)-derived fibroblast-like cells (hESdFs) supported the efficient generation of hepatocyte-like cells (HLCs) with functional and mature hepatic phenotypes from primate ESCs and human induced pluripotent stem cells (iPSCs). Molecular and immunocytochemistry analyses revealed that hESdFs caused a rapid loss of pluripotency and induced a sequential endoderm-to-hepatocyte differentiation in the central area of ESC colonies. Knockdown experiments demonstrated that pluripotent stem cells were directed toward endodermal and hepatic lineages by FGF2 and Activin A secreted from hESdFs. Furthermore, we found that the central region of ESC colonies was essential for the hepatic endoderm-specific differentiation, as its removal caused a complete disruption of endodermal differentiation. In conclusion, we describe a novel in vitro differentiation model, and show that hESdF-secreted factors act in concert with regional features of ESC colonies to induce robust hepatic endoderm differentiation in primate pluripotent stem cells. Total RNA were isolated from ORMES6 ESC, differentiated cells at IVDS2 and 3, and cells in the central foci (IVDS2-C) and peripheral (IVDS2-P) area of ESC colonies at IVDS2. Each condition was repeated twice and used ORMES6 ESC as control.
Project description:Reprogrammed somatic cells offer a valuable source of pluripotent cells that have the potential to differentiate into many cells types and provide a new tool for regenerative medicine. In the present study we differentiated induced pluripotent stem cells (iPS cells) into hepatic cells. We first showed that mouse iPS cells could from a complete liver in mouse embryo (E14.5) including hepatocytes, endothelial cells, sinusoidal cells and resident macrophages. We then designed a highly efficient hepatocyte differentiation protocol using defined factors on human embryonic stem cells (ES cells). This protocol was found to generate more than 80% albumin expressing cells that show hepatic functions and express most of liver genes as shown by microarray analyses. Similar results were obtained when human iPS cells were induced to differentiate following the same procedure. Experiment Overall Design: Total RNA was harvested from the following sources and used for Affymetrix array analysis following manufacturer defined protocols: Experiment Overall Design: 1) human foreskin fibroblasts, ATCC cell line CRL2097, 3 independent cultures Experiment Overall Design: 2) induced pluripotent stem (iPS) cells derived from CRL2097, 3 independent undifferentiated cultures Experiment Overall Design: 3) induced pluripotent stem (iPS) cells derived from CRL2097, 3 independent cultures harvested at day 20 (d20) of a hepatic differentiation protocol Experiment Overall Design: 4) WAO9 human embryonic stem cells, 3 independent undifferentiated cultures Experiment Overall Design: 5) WAO9 human embryonic stem cells, 3 independent cultures harvested at day 20 (d20) of a hepatic differentiation protocol. <br><br>This experiment was reloaded in November 2010 after additional curation
Project description:The future clinical use of embryonic stem cell (ESC)-based hepatocyte replacement therapy depends on the development of an efficient procedure for differentiation of hepatocyes from ESCs. Here we report that a high density of human embryonic stem cell (ESC)-derived fibroblast-like cells (hESdFs) supported the efficient generation of hepatocyte-like cells (HLCs) with functional and mature hepatic phenotypes from primate ESCs and human induced pluripotent stem cells (iPSCs). Molecular and immunocytochemistry analyses revealed that hESdFs caused a rapid loss of pluripotency and induced a sequential endoderm-to-hepatocyte differentiation in the central area of ESC colonies. Knockdown experiments demonstrated that pluripotent stem cells were directed toward endodermal and hepatic lineages by FGF2 and Activin A secreted from hESdFs. Furthermore, we found that the central region of ESC colonies was essential for the hepatic endoderm-specific differentiation, as its removal caused a complete disruption of endodermal differentiation. In conclusion, we describe a novel in vitro differentiation model, and show that hESdF-secreted factors act in concert with regional features of ESC colonies to induce robust hepatic endoderm differentiation in primate pluripotent stem cells.
