Figure 4

Epithelial dysregulation in colons of Irf1^−/− mutants after AOM/DSS treatment. (A) Representative images of immunofluorescence staining of frozen section for proliferation marker Ki67 (red), with control nuclear DNA stain DAPI (blue); Scale bars indicate 100μm. (B) Quantification of the number of hyperproliferative crypts compared to normal crypts from 5 fields of view examined under 10X magnification; Significance was determined using a one-way ANOVA with Bonferroni’s multiple-comparison test (**<0.01, ***<0.001). (C) Relative expression of negative regulators of cell cycle progression Usf1 and Dact2 in the colons of control and treated B6 (n = 4) and Irf1^−/− mutants (n = 6) measured by qRT-PCR and shown as relative expression compared to an internal Hprt control. (D) GSEA analysis of intestinal stem cell signatures as described in Materials and Methods. (E) Flow cytometry of intestinal epithelial cells in B6 and Irf1^−/− mice (n = 3 for B6 and Irf1^−/− CTL, n = 5 for B6 and Irf1^−/− D26) for CD44⁺ intestinal stem cells^, presented as percentage of total EpCAM⁺ epithelial cells.