Expression of the liver‐specific gene Cyp7a1 reveals hepatic differentiation in embryoid bodies derived from mouse embryonic stem cells

Abstract

Hepatic differentiation from mouse embryonic stem (ES) cells via the formation of embryoid bodies (EBs) has been revealed by the expression of hepatocyte-related genes such as α α α α -fetoprotein and albumin. It is known, however, that the visceral endoderm differentiates in early EBs and expresses these hepatocyte-related genes. Thus, it remains unclear whether ES cells are capable of differentiating into hepatocytes derived from definitive endoderm in vitro . In the present study, yolk sac tissues isolated from the foetal mouse were found to express many hepatocyte-related genes. Among the hepatocyte-related genes examined, cytochrome P450 7A1 (Cyp7a1) was identified as a liver-specific gene that was not expressed in the yolk sac. Cyp7a1 was induced in developing EBs, and hepatic differentiation was preferentially observed in the developing EBs in attached culture as compared to those in suspension culture. Leukaemia inhibitory factor permitted the differentiation of visceral endoderm, but inhibited the expression of gastrulation-related genes and the hepatic differentiation in cultured EBs. ES cells expressing green fluorescent protein (GFP) under the control of the Cyp7a1 enhancer/promoter showed that cultured EBs contained GFP-positive epithelial-like cells. These results demonstrate that ES cells can differentiate in vitro into hepatocytes derived from definitive endoderm.

Differentiation of Monkey Embryonic Stem Cells into Hepatocytes and mRNA Expression of Cytochrome P450 Enzymes Responsible for Drug Metabolism: Comparison of Embryoid Body Formation Conditions and Matrices

“…17,18) The in vitro approaches involve the formation of embryoid bodies (EBs) to mimic the inductive microenvironment required for liver organogenesis [19][20][21] and treatment with specific growth factors and cytokines critical for hepatic differentiation.…”

“…16) After birth, CYP7A1 increases several-fold with age both at the enzyme activity level and the mRNA level. 17,18) The in vitro approaches involve the formation of embryoid bodies (EBs) to mimic the inductive microenvironment required for liver organogenesis [19][20][21] and treatment with specific growth factors and cytokines critical for hepatic differentiation. 22) At present, culture systems for ES cells have mainly used gelatin-or collagen-coated plates as the matrix for the maintenance of cells in an undifferentiated state and differentiation.…”

Study of hepatocyte differentiation using embryonic stem cells

“…Spontaneous differentiation of mouse ES cells occurs when the cells are grown in suspension and form EBs [Abe et al, 1996;Chinzei et al, 2002;Jones et al, 2002;Miyashita et al, 2002;Yamada et al, 2002;Asahina et al, 2004;Kumashiro et al, 2005]. In order to direct the differentiation towards the endoderm lineage, various growth factors were used.…”

Pluripotent stem cells to hepatocytes, the journey so far

“…Pluripotent stem cells can be aggregated to form embryoid bodies and can be differentiated by exposure to specific cytokine and growth factor cocktails (40). However, all the existing embryoid body-based protocols suffer from low differentiation efficiency and spontaneous differentiation which gives rise to unwanted cell lineages (41)(42)(43). As monolayer culture can be adjusted to avoid most of these issues, it has been utilised widely and is capable of producing relatively pure populations of cells with hepatic function.…”