Niche-independent high-purity cultures of Lgr5+ intestinal stem cells and their progeny

Although Lgr5+ intestinal stem cells have been expanded in vitro as organoids, homogeneous culture of these cells has not been possible so far. Here we show that two small molecules, CHIR99021 and valproic acid, synergistically maintain self-renewal of mouse Lgr5+ intestinal stem cells, resulting in nearly homogeneous cultures. The colony-forming efficiency of cells from these cultures is ~100-fold greater than that of cells cultured in the absence of CHIR99021 and valproic acid, and multilineage differentiation ability is preserved. We made use of these homogeneous cultures to identify conditions employing simultaneous modulation of Wnt and Notch signaling to direct lineage differentiation into mature enterocytes, goblet cells and Paneth cells. Expansion in these culture conditions may be feasible for Lgr5+ cells from the mouse stomach and colon and from the human small intestine. These methods provide new tools for the study and application of multiple intestinal epithelial cell types. Total RNA was isolated from two independently established wild-type mouse small intestinal organoid lines after culture for 6 days in control condition or in the presence of CHIR99021, Valproic Acid (VPA) or both compounds. cRNA was labeled with Cy5 and hybridized against Cy3 labeled cRNA from control organoids (as an internal reference) on 4X44K Agilent Whole Mouse Genome dual colour Microarrays (G4122F), resulting in eight individual arrays.