Fig. 2. Intestinal Rnf20 and Rnf40 deletion results in spontaneous colorectal inflammation in mice.

A Homozygous Rnf20 or Rnf40 deletion resulted in decreased colon length. B The knockout efficiency in Rnf20^fl/fl and Rnf40^fl/fl mice was demonstrated using IHC for H2Bub1 on colon sections. C Colons were H&E-stained and (D) the percentage of segments with mild [1], medium [2], or severe [3] epithelial damage was determined. Rnf20 and Rnf40 intestine-specific knockout mice displayed more areas with epithelial damage than wildtype or heterozygous animals. E Based on the damage, the H score was calculated and shown to be elevated upon the loss of Rnf20 and Rnf40. F IHC for CD45-positive cells in the colon revealed (G) increased infiltration of immunoregulatory cells. Scale bar: 100 µm. One-way ANOVA, mean ± SEM.