Novel targets identified in gene expression profiles from patients with inflammatory bowel disease

Abstract

a non discriminative way and thus selected the un-expressed cII gene in LIZ transgenes of Big Blue ™ (BB) mice to study. Because the available BB mice were on B6 genetic background, which has profound effect on tumor susceptibility, we generated B6 BB Gpx1/2-DKO mice and studied their phenotype. The B6 BB Gpx1/2-DKO mice had fewer inflammatory cells, milder ileocolitis, low mortality before 7 weeks of age, and only 2.5% of them developed tumors between 6-8 months old. Whether these Gpx1/2-DKO mice have LIZ transgenes or not does not affect these phenotype. We have then generated B6.129 BB Gpx1/2-DKO mice by breeding the B6 BB Gpx1/2-DKO mice with 129 mice. We then studied spontaneous gene mutations in the ileal and colonic epithelium, as well as the non-affected liver in the cII gene in both B6 and B6.129 BB Gpx1/2-DKO mice and their control. RESULTS AND CONCLUSIONS: The mutant frequency of a cII reporter gene was about 2-3 fold higher in 28-day-old Gpx1/2-DKO mouse ileal epithelia and 4-fold higher in 8-month-old Gpx1/2-DKO ileal epithelium than in controls in both genetic backgrounds. In contrast, mutant frequencies in the unaffected B6 liver were not different between wildtype and Gpx1/2-DKO mice. The mutant frequency of 8-month-old B6.129 Gpx1/2-DKO ileum was 38.94Ϯ15.5 -5 , which was higher than the age-matched B6 ileum, 25.54Ϯ10.33 -5 , although not statistically significant. The mutation spectra analysis has shown that B6 Gpx1/2-DKO ileum had a 3-fold increase in small nucleotide deletions at mononucleotide repeats over control B6, which are a signature mutation associated with oxidative stress. Unexpectedly, B6 Gpx1/2-DKO mice had fewer C to T transitions at CpG dinucleotides than the wildtype B6 (18.0% versus 40.1%; PϽ0.001). Our results suggest inflammation drives gene mutations, which by themselves are not sufficient for neoplastic transformation of intestinal epithelial cells.

Applications of proteomics in the study of inflammatory bowel diseases

“…The authors showed that in CD, 4 analytes (PLGF, IL-7, IL-12p40, and TGF-beta1) were significantly elevated in patients in clinical remissions when compared to those with active disease, while in UC only 1 cytokine (IL12p40) showed significance between clinical remissions and active disease. This study (32) suggests that these cytokines are directly involved intestinal inflammation in IBD, and is in agreement with our data obtained by multiplex ELISA (33, 34). …”

“…It is necessary to point out that another powerful protein/antibody-based technology, multiplex ELISA, was not included in this review. Recently multiplex ELISA has been proven as a robust approach to profile biomarkers of various diseases, and we have demonstrated its potential in profiling and identifying serum cytokines/chemokines as serological IBD biomarkers (32, 33). It’s evident that the proteomic study of IBD is in a very early stage, when compared to its application in other diseases (such as cancer).…”

“…Cell lines have been used extensively as an in vitro model in the study of the modulation of protein expression in IBD (33, 63–65). Various intestinal epithelial cell lines (such as Caco-2, HT29 and T84), immortalized T cells, and EBV-transformed human B-cell lines are some of in vitro models for IBD-related studies (33, 63–65).…”

“…Various intestinal epithelial cell lines (such as Caco-2, HT29 and T84), immortalized T cells, and EBV-transformed human B-cell lines are some of in vitro models for IBD-related studies (33, 63–65). At least three proteomic studies that may be relevant to IBD have been reported using colonic epithelial cells.…”