Fig 1: P16 deletion improved destruction of TJ and increasing barrier permeability in intestinal epithelium in Bmi-1–/– mice. The experiments were carried out on the 7-week-old Bmi-1–/–, Bmi-1–/–p16–/–, and WT mice. (A) Representative micrographs showing immunofluorescence for ZO-1 and occludin, with DAPI staining the nuclei. (B) Percentage of ZO-1–positive areas relative to the total area. (C) Percentage of occludin-positive areas relative to the total area. (D) Intestinal FITC–dextran transmittance showing intestinal permeability. (E) Representative micrographs showing transmission electron microscope for the epithelial cells of jejunum, ileum, and colon, with blue arrow showing the bottom of the epithelial TJ. (F) Western blots for claudin-1, occludin, claudin-2, TNF-a, and NF-?B–p65 in the epithelial cells of jejunum, ileum, and colon; ß-actin was used as the loading control. (G) Protein levels relative to ß-actin were assessed by densitometric analysis. Six mice per group were used for experiments. Statistical analysis was performed with one-way ANOVA test. Values are mean ± SEM from six determinations per group, *p < 0.05, **p < 0.01, ***p < 0.001 compared with the WT group; #p < 0.05, ##p < 0.01, ###p < 0.001compared with the Bmi-1–/– group.