Chronic levels of intestinal tissue inflammation in IBD are associated with increased crypt cell apoptosis and an increased risk for development of colorectal cancer. Our results implicate p53 activation as a key step in mediating crypt cell apoptosis in states of intestinal inflammation. The primary role of p53 is to protect developing cells by repairing DNA damage and/or inducing apoptosis. The importance of p53 in the intestine is highlighted by observations that p53 mutations are detected early in patients with chronic UC (even before dysplasia), whereas in sporadic forms of colon cancer, p53 mutations occur relatively late. Specifically, 70% of UC-associated cancers and 20% of dysplastic lesions analyzed in UC contain p53 mutations. These clinical observations increase the importance of discovering mechanisms for p53 induction and activation during tissue inflammation. Studies in the present aim will utilize the anti-CD3 mAb-treated mouse model of T cell-induced crypt cell apoptosis. Based on preliminary results, we hypothesize that epithelial TNF receptor 1 and 2 signaling in epithelial cells induce epithelial p53 expression whereas TNF-induced iNOS expression in BM-derived cells releases NO that activates p53 protein and induces expression of downstream p53 target genes involved in crypt cell apoptosis. The elements of this pathway will be explored in the current proposal. First, we will examine the cellular and molecular pathways involved in TNF receptor signaling and iNOS induction during Tell-induced activation of p53. These studies will restrict expression of TNFR-1, TNFR-2, and iNOS to epithelial Vs BM-derived cells and examine p53 activation, expression of p53 targets and induction of crypt cell apoptosis. Next, we plan to examine the downstream effectors of p53. We will use specific gene knockout mice (bax/bak and bid-/-) to address hypotheses based on analysis of p53 target genes in wild type and p53 null mice. Our previous studies significantly advanced out understanding of the critical steps in T cell-induced crypt cell apoptosis, yet there are key questions that remain unanswered. The current proposal will move us closer to understanding the cellular and molecular events required for the induction of crypt cell apoptosis in intestinal inflammation. These studies will enhance our understanding of the mechanisms relevant to normal crypt cell death and add insight into the pathways involved in the induction of intestinal carcinogenesis in IBD.

Agency
National Institute of Health (NIH)
Institute
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Type
Research Project (R01)
Project #
5R01DK054778-08
Application #
7035403
Study Section
General Medicine A Subcommittee 2 (GMA)
Program Officer
Hamilton, Frank A
Project Start
1999-02-15
Project End
2009-03-31
Budget Start
2006-04-01
Budget End
2007-03-31
Support Year
8
Fiscal Year
2006
Total Cost
$287,765
Indirect Cost
Name
Northwestern University at Chicago
Department
Internal Medicine/Medicine
Type
Schools of Medicine
DUNS #
005436803
City
Chicago
State
IL
Country
United States
Zip Code
60611
Cohran, Valeria; Managlia, Elizabeth; Bradford, Emily M et al. (2016) Epithelial PIK3R1 (p85) and TP53 Regulate Survivin Expression during Adaptation to Ileocecal Resection. Am J Pathol 186:1837-1846
Managlia, Elizabeth; Katzman, Rebecca B; Brown, Jeffrey B et al. (2013) Antioxidant properties of mesalamine in colitis inhibit phosphoinositide 3-kinase signaling in progenitor cells. Inflamm Bowel Dis 19:2051-60
Krishnan, K; Komanduri, S; Cluley, J et al. (2012) Radiofrequency ablation for dysplasia in Barrett's esophagus restores ?-catenin activation within esophageal progenitor cells. Dig Dis Sci 57:294-302
Goretsky, Tatiana; Dirisina, Ramanarao; Sinh, Preetika et al. (2012) p53 mediates TNF-induced epithelial cell apoptosis in IBD. Am J Pathol 181:1306-15
Brown, Jeffrey B; Cheresh, Paul; Zhang, Zheng et al. (2012) P-selectin glycoprotein ligand-1 is needed for sequential recruitment of T-helper 1 (Th1) and local generation of Th17 T cells in dextran sodium sulfate (DSS) colitis. Inflamm Bowel Dis 18:323-32
Dirisina, Ramanarao; Katzman, Rebecca B; Goretsky, Tatiana et al. (2011) p53 and PUMA independently regulate apoptosis of intestinal epithelial cells in patients and mice with colitis. Gastroenterology 141:1036-45
Mohamadzadeh, Mansour; Pfeiler, Erika A; Brown, Jeffrey B et al. (2011) Regulation of induced colonic inflammation by Lactobacillus acidophilus deficient in lipoteichoic acid. Proc Natl Acad Sci U S A 108 Suppl 1:4623-30
Brown, Jeffrey B; Cheresh, Paul; Goretsky, Tatiana et al. (2011) Epithelial phosphatidylinositol-3-kinase signaling is required for ýý-catenin activation and host defense against Citrobacter rodentium infection. Infect Immun 79:1863-72
Lee, Goo; Goretsky, Tatiana; Managlia, Elizabeth et al. (2010) Phosphoinositide 3-kinase signaling mediates beta-catenin activation in intestinal epithelial stem and progenitor cells in colitis. Gastroenterology 139:869-81, 881.e1-9
Brown, Jeffrey B; Lee, Goo; Managlia, Elizabeth et al. (2010) Mesalamine inhibits epithelial beta-catenin activation in chronic ulcerative colitis. Gastroenterology 138:595-605, 605.e1-3

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