Signals from Embryonic Fibroblasts Induce Adult Intestinal Epithelial Cells to Form Nestin‐Positive Cells with Proliferation and Multilineage Differentiation Capacity In Vitro

The intestinal epithelium has one of the greatest regenerative capacities in the body; however, neither stem nor progenitor cells have been successfully cultivated from the intestine. In this study, we applied an "artificial niche" of mouse embryonic fibroblasts to derive multipotent cells from the intestinal epithelium. Cocultivation of adult mouse and human intestinal epithelium with fibroblast feeder cells led to the generation of a novel type of nestin-positive cells (intestinal epithelium-derived nestin-positive cells [INPs]). Transcriptome analyses demonstrated that mouse embryonic fibroblasts expressed relatively high levels of Wnt/bone morphogenetic protein (BMP) transcripts, and the formation of INPs was specifically associated with an increase in Lef1, Wnt4, Wnt5a, and Wnt/BMP-responsive factors, but a decrease of BMP4 transcript abundance. In vitro, INPs showed a high but finite proliferative capacity and readily differentiated into cells expressing neural, pancreatic, and hepatic transcripts and proteins; however, these derivatives did not show functional properties. In vivo, INPs failed to form chimeras following injection into mouse blastocysts but integrated into hippocampal brain slice cultures in situ. We conclude that the use of embryonic fibroblasts seems to reprogram adult intestinal epithelial cells by modulation of Wnt/BMP signaling to a cell type with a more primitive embryonic-like stage of development that has a high degree of flexibility and plasticity.