Pancreatic exocrine enzyme-producing cell differentiation via embryoid bodies from human embryonic stem cells.

Mouse embryonic stem cells (ESCs) can be induced to form pancreatic exocrine enzyme-producing cells in vitro in a stepwise fashion that recapitulates the development in vivo. However, there is no protocol for the differentiation of pancreatic-like cells from human ESCs (hESCs). Based upon the mouse ESC model, we have induced the in vitro formation of pancreatic exocrine enzyme-producing cells from hESCs. The protocol took place in four stages. In Stage 1, embryoid bodies (EBs) were formed from dissociated hESCs and then treated with the growth factor activin A, which promoted the expression of Foxa2 and Sox17 mRNAs, markers of definitive endoderm. In Stage 2, the cells were treated with all-trans retinoic acid which promoted the transition to cells that expressed gut tube endoderm mRNA marker HNF1b. In Stage 3, the cells were treated with fibroblast growth factor 7 (FGF7), which induced expression of Pdx1 typical of pancreatic progenitor cells. In Stage 4, treatment with FGF7, glucagon-like peptide 1, and nicotinamide induced the expression amylase (AMY) mRNA, a marker for mature pancreatic exocrine cells. Immunohistochemical staining showed the expression of AMY protein at the edges of cell clusters. These cells also expressed other exocrine secretory proteins including elastase, carboxypeptidase A, chymotrypsin, and pancreatic lipase in culture. Production of these hESC-derived pancreatic enzyme-producing cells represents a critical step in the study of pancreatic organogenesis and in the development of a renewable source of human pancreatic-like exocrine cells.