Embryonic stem differentiation into functional hepatocytes: assessment of maturity

The large quantities of hepatocytes necessary for the support of artificial liver assist devices and drug discovery studies drives the need for the identification of a sustainable source of mature hepatocytes. Embryoid body (EB) mediated differentiation of stem cells in the presence of growth factor (GF) and extracellular matrix (ECM) supplementation has been shown to produce populations of hepatocyte lineage cells expressing mature hepatocyte markers such as albumin (ALB) and glucose-6-phosphate (G-6-P). In the present study we have identified a controlled tissue culture platform which was then used to study the effects of GF´s alone, collagen alone, both GF´s and collagen and spontaneous differentiation on protein and gene expression levels of differentiated ES cells. In-situ immunofluorescence techniques and cDNA microarrays were used to give an indication of maturity. The data suggests that spontaneous and collagen mediated differentiation produce cells with the highest levels of in-situ ALB expression but upregulated liver specific genes where only found in the spontaneous condition.