Figure 4.

IEC-specific loss of Lpar5 results in IEC death in mice and cultured enteroids. (A) Lpar5^f/f and Lpar5^f/f;AhCre mice were treated by β-NF (80 mg/kg body weight) for 5 consecutive days and mice were euthanized 5 days after the last treatment. Representative hematoxylin and eosin images showing the histology of the small intestine of Lpar5^f/f and Lpar5^IECKO mice. Scale bar = 100 μm. (B) Representative IF images of TUNEL (red) staining in the intestinal sections of Lpar5^f/f and Lpar5^IECKO mice. Scale bar = 100 μm. (C) Time course of epithelial cell apoptosis was determined by treating Lpar5^f/f;AhCre mice (left, n = 80) or Lpar5^f/f mice (right, n = 30) with β-NF for 5 consecutive days from day 0 (D0) to D5. TUNEL⁺ cell numbers per crypt were quantified each day. All data are presented as mean ± SD. ∗∗∗P < .001, ∗∗∗∗P < .0001 compared with D0 by 1-way analysis of variance with Tukey’s multiple comparison test. (D) Representative images of EdU⁺ cells in the crypts of Lpar5^IECKO and Lpar5^f/f mice. Scale bar = 100 μm. (E) Quantification of EdU⁺ cells per crypt (mean ± SD) in Lpar5^f/f and Lpar5^IECKO mice. n = 30. ∗∗∗P < .001 by unpaired, 2-tailed t test. (F) Enteroids from Lpar5^f/f and Lpar5^f/f;AhCre mice were treated with 1 μM β-NF and images were taken before (0) and 72 hours of treatment. Representative of 3 experiments. (G) Representative EdU (green), TUNEL (red), and DAPI (blue) staining of enteroids are shown.