We recently reported a novel method to induce embryonic stem (ES) cells differentiate into an endodermal fate, especially pancreatic, using a supporting cell line. Here we describe the modified culture condition with the addition and withdrawal of secreted growth factors could induce ES cells to selectively differentiate into a hepatic fate efficiently. The signaling of BMP and FGF that have been implicated in hepatic differentiation during normal embryonic development are shown to play pivotal roles in generating hepatic cells from the definitive endoderm derived from ES cells. Moreover, the expression of AFP, Albumin or a biliary molecular marker appeared sequentially thus suggested the differentiation of ES cells recapitulated normal developmental processes of liver. The ES cell‐derived differentiated cells showed evidence of glycogen storage, secreted Albumin, exhibited drug metabolism activities and expressed a set of cytochrome or drug conjugate enzymes, drug transporters specifically expressed in mature hepatocytes. With the same procedure, human ES cells also gave rise to cells with mature hepatocytes’ characteristics. In conclusion, this novel procedure for hepatic differentiation will be useful for elucidation of molecular mechanisms of hepatic fate decision at gut regionalization, and could represent an attractive approach for a surrogate cell source for pharmaceutical studies such as toxicology.

Cell replacement therapy for diabetes mellitus requires cost-effective generation of high-quality, insulin-producing, pancreatic β cells from pluripotent stem cells. Development of this technique has been hampered by a lack of knowledge of the molecular mechanisms underlying β-cell differentiation. The present study identified reserpine and tetrabenazine (TBZ), both vesicular monoamine transporter 2 (VMAT2) inhibitors, as promoters of late-stage differentiation of Pdx1-positive pancreatic progenitor cells into Neurog3 (referred to henceforth as Ngn3)-positive endocrine precursors. VMAT2-controlled monoamines, such as dopamine, histamine and serotonin, negatively regulated β-cell differentiation. Reserpine or TBZ acted additively with dibutyryl adenosine 3',5'-cyclic AMP, a cell-permeable cAMP analog, to potentiate differentiation of embryonic stem (ES) cells into β cells that exhibited glucose-stimulated insulin secretion. When ES cell-derived β cells were transplanted into AKITA diabetic mice, the cells reversed hyperglycemia. Our protocol provides a basis for the understanding of β-cell differentiation and its application to a cost-effective production of functional β cells for cell therapy.

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Although progresses in developing differentiation procedures have been achieved, it remains challenging to generate hES/iPS cell-derived mature hepatocytes. We performed knock-in of a monomeric Kusabira orange (mKO1) cassette in the albumin (ALB) gene, in human embryonic stem (hES) cells and induced pluripotent stem (hiPS) cells, with the use of the helper-dependent adenovirus vector (HDAdV). Upon induction into the hepatic lineages, these knock-in hES/iPS cells differentiated into cells that displayed several known hepatic functions. The mKO1 knock-in (ALB/mKo1) hES/hiPS cells were used to visualize hepatic differentiation in vitro. mKO1 reporter expression recapitulated endogenous ALB transcriptional activity. ALB/mKo1 [Hi] population isolated by flow cytometry was confirmed to be enriched with ALB mRNA. Expression profile analyses revealed that characteristic hepatocyte genes and genes related to drug metabolism and many aspects of liver function were highly enriched in the ALB/mKo1 [Hi] population. Our data demonstrate that ALB/mKo1 knock-in hES/iPS cells are valuable resources for monitoring in vitro hepatic differentiation, isolation and analyses of hES and hiPS cells-derived hepatic cells that actively transcribing ALB. These knock-in hES/iPS cell lines could provide further insights into the mechanism of hepatic differentiation and molecular signatures of the hepatic cells derived from hES/iPS cells.

C2cd4c, encoded by a gene belonging to the C2cd4 family, contains a C2 domain conserved across species and is localized to the cytoplasm. To examine the role of C2cd4c in the pancreas, we studied its localization and generated C2cd4c knockout (KO) mice. C2cd4c was expressed in pancreatic endocrine progenitors at early embryonic stages. When endocrine cells arise from their precursors, C2cd4c is gradually confined to the insulin‐ and pancreatic polypeptide‐expressing cells of the endocrine. In the adult pancreas, C2cd4c is restricted to the beta cells. C2cd4c KO mice showed normal embryonic pancreatic development and adult pancreatic function. Thus, our results suggest that C2cd4c is dispensable for pancreatic development.