The aim of this study was to identify an epithelial cell line isolated from the spontaneous differentiation of totipotent pig epiblast cells.Methods
PICM-31 and its colony-cloned derivative cell line, PICM-31A, were established from the culture and differentiation of an epiblast mass isolated from an 8-day-old pig blastocyst. The cell lines were analyzed by transmission electron microscopy, marker gene expression, and mass spectroscopy-based proteomics.Results
The PICM-31 cell lines were continuously cultured and could be successively colony cloned. They spontaneously self-organized into acinarlike structures. Transmission electron microscopy indicated that the cell lines' cells were epithelial and filled with secretory granules. Candidate gene expression analysis of the cells showed an exocrine pancreatic profile that included digestive enzyme expression, for example, carboxypeptidase A1, and expression of the fetal marker, α-fetoprotein. Pancreatic progenitor marker expression included pancreatic and duodenal homeobox 1, NK6 homeobox 1, and pancreas-specific transcription factor 1a, but not neurogenin 3. Proteomic analysis of cellular proteins confirmed the cells' production of digestive enzymes and showed that the cells expressed cytokeratins 8 and 18.Conclusions
The PICM-31 cell lines provide in vitro models of fetal pig pancreatic exocrine cells. They are the first demonstration of continuous cultures, that is, cell lines, of nontransformed pig pancreas cells.