In vitro functional gut-like organ formation from mouse embryonic stem cells.

BACKGROUND AND AIMS: Embryonic stem (ES) cells have a pluripotent ability to differentiate into a variety of cell lineages in vitro. We have recently found that ES cells can give rise to a functional gut-like unit, which forms a three-dimensional dome-like structure with lumen and exhibits mechanical activity, such as spontaneous contraction and peristalsis. The aim of the present study was to investigate the electrophysiological and morphological properties of ES cell-derived contracting clusters. METHODS: Electrical activity was examined by an extracellular recording. Morphology and cellular components were investigated by immunohistochemistry and electron microscopy. RESULTS: Clusters with rhythmic contractions displayed electrical slow waves at a regular rhythm, and clusters with highly coordinated peristalsis showed regular slow waves and spontaneous spike action potentials. Immunoreactivity for c-Kit, a marker of interstitial cells of Cajal (ICC), was observed in dense network structures. Neuronal marker PGP9.5 immunoreactivity was observed only in clusters with peristalsis. The topographical structure of the wall was organized by an inner epithelial layer and outer smooth muscle layer. The smooth muscle layer was provided with an ICC network and innervated with enteric neurons. CONCLUSIONS: ES cells can differentiate into a functional gut-like organ in vitro that exhibits physiological and morphological properties characteristic of the gastrointestinal (GI) tract. This ES cell-derived gut provides a powerful tool for studying GI motility and gut development in vitro, and has potential for elucidating and treating a variety of motility disorders.