BioProject

Proliferation of the self-renewing epithelium of the gastric corpus occurs almost exclusively in the isthmus of the glands, from where cells migrate bi-directionally towards pit and base. More...

Proliferation of the self-renewing epithelium of the gastric corpus occurs almost exclusively in the isthmus of the glands, from where cells migrate bi-directionally towards pit and base. The isthmus is therefore generally viewed as the stem cell zone. We find that the stem cell marker Troy is expressed at the gland base by a small subpopulation of chief cells. By lineage tracing using a Troy-eGFP-ires-CreERT2 allele, single marked cells are shown to generate entirely labeled gastric units over periods of months. This phenomenon accelerates upon tissue damage. Troy+ chief cells can be cultured to generate long-lived gastric organoids. Troy marks a specific, 'plastic' subset of differentiated chief cells capable of replenishing entire gastric units, essentially serving as a quiescent ‘reserve’ stem cell. Overall design: An EGFP-ires-CreERT2 cassette was introduced into the transcriptional start side of Tnfrsf19 (Troy), resulting in the expression of EGFP and CreERT2 under the control of endogenous Troy-regulatory sequences. Troy is expressed in basally located chief and parietal cells. Using FACS, Troy positive chief and parietal cells can be isolated separately. Expression profiling was performed on these two cell types: three arrays of sorted chief cells, two arrays of sorted parietal cells. As a reference, two arrays of separately isolated whole gastric corpus glands were added. In addition, single sorted Troy positive chief cells can be placed in culture, forming 3D cultures called organoids. Three arrays were generated from different organoid cultures, one time in normal medium containing the factors EGF, Gastrin, FGF10, Noggin, Wnt3a and Rspondin (EGFNWR medium) and one time in medium containing only EGF and Rspondin (ER medium). Less...