Previous experimental evidence has indicated that the loss of Bmf causes defects in uterovaginal development, e.g. an imperforate vagina and hydrometrocolpos [22]. We analysed phenotypic abnormalities of Bim–/– animals in the anal canal. Animals were kept in IVC under SPF conditions. Rectum prolapses were found in 18 of 104 Bim–/– animals (Fig. 1a,b) which have not been used for breeding; anal bleeding was observed in those mice. No increase in collagen deposition in Bim–/– colon was detectable by Sirius red and Elastica von Giesson staining (not shown). Analysis of the length of collagen fibrils by polarized
light microscopy find more also revealed no change in Bim–/– animals with prolapse compared to wild-type mice without prolapse. Colon length was not altered in Bim–/– animals compared to wild-type mice (8·0 ± 1·0, n = 18 versus 7·9 ± 0·8, n = 15, respectively, not shown). Transepithelial resistance was measured at a 1–2 cm distance from the distal end of the colon. Transepithelial resistance was not altered in Bim–/– animals compared to wild-type mice (35 ± 5 Ω × cm2, n = 5 versus 39 ± 6 Ω × cm2, n = 5, respectively, female mice without rectum prolapse, not shown). Previous experimental evidence has reported impaired cell death of lymphocytes in the absence of Bim [18]. We analysed peripheral blood from seven wild-type
Selleckchem SB203580 controls and seven Bim–/– mice on an ADVIA 2120i haematology system (Siemens AG, Munich, Germany). The total number of leucocytes was increased significantly in Bim–/– mice compared to wild-type controls (8·21 ± 2·52 × 109 cells/l versus 1·66 ± 0·48 × 109 cells/l, P < 0·001). Total
numbers of lymphocytes (6·61 ± 2·90 × 103 cells/μl versus 1·24 ± 0·34 × 103 cells/μl, P < 0·001), neutrophilic leucocytes (1·20 ± 1·27 × 103 cells/μl versus 0·28 ± 0·25 × 103 cells/μl, P < 0·001) and eosinophilic leucocytes (0·24 ± 0·20 × 103 cells/μl versus 0·06 ± 0·03 × 103 cells/μl, P < 0·001) were increased significantly in Bim–/– mice compared to wild-type controls. In contrast, the proportion of monocytes was decreased significantly in Bim–/– mice compared to wild-type controls (0·91 ± 0·30 versus 2·73 ± 1·24, P < 0·001). Consistently, we observed a significant difference in the spleen Clomifene weight between Bim–/– and wild-type mice (spleen weight/body weight 7·7 ± 0·9 mg/g, n = 10 versus 4·2 ± 0·4 mg/g, n = 5; respectively, P < 0·05, Fig. 3a). As we found rectum prolapses, anal bleeding and a significant increase in the spleen weight in our Bim–/– animals, we focused on Bim dependence of intestinal inflammation and lymphocyte apoptosis in chronic DSS-induced colitis. Upon chronic DSS-induced colitis, the weight loss of Bim–/– mice was significantly higher compared to wild-type mice during the last days before the animals were killed (Fig. 2a). The macroscopic mucosal damage was assessed by colonoscopy and MEICS [20].