ANKRD22 deletion results in rapid proliferation of the Lgr5+gastric EPCs. (A) Detection of Lgr5+ cells in injured gastric mucosa of Lgr5–EGFP–IRES–creERT2 knockin mice. Mice were subjected to subsequent detection at 24 hours after intragastric administration of EtOH/HCl or saline solution (Ctrl). Arrow, Lgr5+ cells. (B and C) Mucin 5AC (Muc5ac), progastricsin (Pgc), somatostatin (Sst), mucin 6 (Muc6), trefoil factor 1 (Tff1), and trefoil factor 2 (Tff2) were expressed in both Lgr5+ and Lgr5- gastric epithelial cells detected by PCR. Lgr5+ and Lgr5- gastric epithelial cells of WT C57BL/6 mice were obtained by FACS at 24 hours after intragastric administration of HCl/EtOH (n = 3). (D) Effect of Ankrd22 knockout on Lgr5 after gastric mucosal injury detected by qRT-PCR. The data from the Ankrd22+/+ control group were normalized to 1.0. TUBB was used as an internal reference. (E and F) Effect of Ankrd22 knockout on the percentage of Lgr5+ cells after gastric mucosal injury detected by FCM. After intragastric administration of EtOH/HCl and observation for 2 hours in advance, Ankrd22+/+ and Ankrd22-/- mice were examined at 0, 24, 48, or 72 hours. Rat IgG2b was used as isotype control (n = 5). (G and H) Effect of Ankrd22 knockout on the percentage of Lgr5+ cells in corpus and antrum after gastric mucosal injury detected by FCM. Rat IgG2b was used as an isotype control. (I) Ankrd22 knockout increased the clone number of primary mouse gastric epithelial cells in organoid culture (n = 3). (J) The percentage of Lgr5+Ki67+ cells in the organoid-enriched primary mouse gastric EPCs was detected by FCM. Rat IgG2b was used as an isotype control (n = 3). (K) Expression of LGR5 and ANKRD22 in human gastric epithelial mucosa with injury and corresponding mucosa without injury in chronic gastritis patients detected by qRT-PCR (n = 20). The data from the corresponding mucosa without injury group were normalized to 1.0. TUBB was used as an internal reference. (L) Correlation analysis of LGR5 and ANKRD22 in the gastric mucosal lesions in patients with chronic gastritis (n = 20). The data were analyzed by the Student t test and presented as means ± SD. ∗P < .05, ∗∗P < .01, and ∗∗∗P < .001. ESC, Epithelial Stem cells; FITC-A, Fluorescein Isothiocyanate Area; FSC-A, Forward Scatter Area; PE-A, Phycoerythrin Area; PE-H, Phycoerythrin Height; SSC-H, Side Scatter Height.