Fig. 1.

Impact of SAP-1 ablation on development of colitis in IL-10–deficient mice. (A) Cryostat sections of the colon of WT or Sap1^−/− mice at 6 wk of age were subjected to immunofluorescence analysis with antibodies to SAP-1 (red) and to β-catenin (green). Nuclei were also stained with DAPI (blue). Boxed regions (Upper) are shown at higher magnification (Lower). [Scale bars, 100 μm (Upper) or 10 μm (Lower).] (B) Immunoelectron microscopy of the colonic epithelium of adult WT or Sap1^−/− mice with antibodies to SAP-1. (Scale bar, 200 nm.) (C) Disease activity for colitis in 10-, 15-, or 20-wk-old Il10^−/− (n = 35, 18, and 19, respectively) or Il10^−/−Sap1^−/− (n = 40, 24, and 24, respectively) mice. *P < 0.05 (Mann–Whitney u test). (D) Incidence of anorectal prolapse in Il10^−/− (n = 38) or Il10^−/−Sap1^−/− (n = 23) mice. (E) H&E staining of midcolon sections from 20-wk-old Il10^−/− or Il10^−/−Sap1^−/− mice. (Scale bars, 200 μm.) (F) Histological score for inflammation in the colon of 20-wk-old Il10^−/− or Il10^−/−Sap1^−/− mice. *P < 0.05 (Mann–Whitney u test). (G) Survival rates of Il10^−/− (n = 36) and Il10^−/−Sap1^−/− (n = 24) mice. Data are representative of three independent experiments (A, B, and E) and pooled from at least three independent experiments (C, D, and G); means ± SEM in C, or are from one representative experiment (F; means ± SEM for a total of five mice for each genotype).