E-cadherin synergistically induces hepatospecific phenotype and maturation of embryonic stem cells in conjunction with hepatotrophic factors

Abstract

Since effective cell sourcing is a major challenge for the therapeutic management of liver disease and liver failure, embryonic stem (ES) cells are being widely investigated as a promising source of hepatic-like cells with their proliferative and pluripotent capacities. Cell-cell interactions are crucial in embryonic development modulating adhesive and signaling functions; specifically, the cell-cell adhesion ligand, cadherin is instrumental in gastrulation and hepatic morphogenesis. Inspired by the role of cadherins in development, we investigated the role of expression of E-cadherin in cultured murine ES cells on the induction of hepatospecific phenotype and maturation. The cadherin-expressing embryonic stem (CE-ES) cells intrinsically formed pro- nounced cell aggregates and cuboidal morphol whereas cadherin-deficient cadherin-expressing embryonic stem (CD-ES) cells remained more spread out and corded in morphology. Through controlled stimulation with single or combined forms of hepatotrophic growth factors; hepatocyte growth factor (HGF), dexamethasone (DEX) and oncostatin M (OSM), we investigated the progressive maturation of CE-ES cells, in relation to the control, CD-ES cells. Upon growth factor treatment, the CE-ES cells adopted a more compacted morphology, which exhibited a significant hepatocyte-like cuboidal appearance in the presence of DEX-OSM-HGF. In contrast, the CD-ES cells exhibited a mixed morphology and appeared to be more elongated in the presence of DEXOSM-HGF. Reverse-transcriptase polymerase chain reac-tion was used to delineate the most differentiating condition in terms of early (alpha-fetoprotein (AFP)), mid (albumin), and late-hepatic (glucose-6-phosphatase) markers in relation to growth factor presentation for both CE-ES and CD-ES cells. We report that following the most differentiating condition of DEX-OSM-HGF stimulation, CE-ES cells expressed increased levels of albumin and glucose-6-phosphatase, whereas the CD-ES cells showed low levels of AFP and marginal levels of albumin and glucose-6-phosphatase. These trends suggest that the membrane expression of E-cadherin in ES cells can elicit a marked response to growth factor stimulation and lead to the induction of later stages of hepatocytic maturation. Thus, cadherin-engineered ES cells could be used to harness the cross-talk between the hepatotrophic and cadherin-based signaling pathways for controlled acceleration of ES hepatodifferentiation. © 2005 Wiley Periodicals, Inc.