Stem cell self-renewal and recovery of intestinal epithelial barrier dysfunction associated with alcohol abuse

In a human gut organoid (HGO) model of alcohol-associated intestinal epithelial barrier dysfunction (EBD), we studied the mechanism of why alcohol-induced EBD is not readily recovered. After exposure to 0.2% ethanol for 15 days, increased bacterial translocation, decreased villus/crypt ratio, decreased growth rate, and decreased numbers of various epithelial cells were shown in HGOs (alcoholized HGOs, A/HGOs). The intestinal EBD in A/HGOs was persisted for 15 days or more after re-cultivation with alcohol-free fresh media. As compared with HGOs cultured with fresh media (control HGOs, C/HGOs), decreased expression of Ki-67 (a marker of cellular proliferation) and LGR5 (a marker of mitotically active intestinal stem cells) was shown in A/HGOs. Also, Ki-67 and LGR5 were not expressed in C/HGOs previously treated with an inhibitor of Notch signalling. The delayed growth and decreased NOTCH1 mRNA expression and Ki-67 and LGR5 protein levels in A/HGOs were restored, at the levels shown in C/HGOs, after co-cultivation with intestinal epithelial cells differentiated from induced pluripotent stem (iPS) cells (iPS-IECs). Minimum bacterial translocation was demonstrated from A/HGOs co-cultured with iPS-IECs, and the decreased ratio of villus/crypt, delayed growth of organoids, and decreased numbers of epithelial cells were restored in A/HGOs co-cultured with iPS-IECs. These results indicate that intestinal EBD associated with alcohol abuse could be repaired through the reactivation of intestinal stem cell self-renewal using iPS-IECs.