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Publications (4)35.45 Total impact

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    ABSTRACT: Inflammatory bowel disease (IBD) arises from inappropriate activation of the mucosal immune system resulting in a state of chronic inflammation with causal links to colon cancer. Helicobacter hepaticus-infected Rag2(-/-) mice emulate many aspects of human IBD, and our recent work using this experimental model highlights the importance of neutrophils in the pathology of colitis. To define molecular mechanisms linking colitis to the identity of disease biomarkers, we performed a translational comparison of protein expression and protein damage products in tissues of mice and human IBD patients. Analysis in inflamed mouse colons identified the neutrophil- and macrophage-derived damage products 3-chlorotyrosine (Cl-Tyr) and 3-nitrotyrosine, both of which increased with disease duration. Analysis also revealed higher Cl-Tyr levels in colon relative to serum in patients with ulcerative colitis and Crohn disease. The DNA chlorination damage product, 5-chloro-2'-deoxycytidine, was quantified in diseased human colon samples and found to be present at levels similar to those in inflamed mouse colons. Multivariate analysis of these markers, together with serum proteins and cytokines, revealed a general signature of activated innate immunity in human IBD. Signatures in ulcerative colitis sera were strongly suggestive of neutrophil activity, and those in Crohn disease and mouse sera were suggestive of both macrophage and neutrophil activity. These data point to innate immunity as a major determinant of serum and tissue profiles and provide insight into IBD disease processes.
    Proceedings of the National Academy of Sciences 06/2013; · 9.81 Impact Factor
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    ABSTRACT: Chronic microbial infection influences cancer progression, but the mechanisms that link them remain unclear. Constitutive androstane receptor (CAR) is a nuclear receptor that regulates enzymes involved in endobiotic and xenobiotic metabolism. CAR activation is a mechanism of xenobiotic tumor promotion; however, the effects of chronic microbial infection on tumor promotion have not been studied in the context of CAR function. Here, we report that CAR limits the effects of chronic infection-associated progression of liver cancer. CAR knockout (KO) and wild-type (WT) male mice were treated with or without the tumor initiator diethylnitrosamine (DEN) at 5 weeks of age and then orally inoculated with Helicobacter hepaticus (Hh) or sterile media at 8 weeks of age. At approximately 50 weeks postinoculation, mice were euthanized for histopathologic, microbiological, molecular, and metabolomic analyses. Hh infection induced comparable hepatitis in WT and KO mice with or without DEN that correlated with significant upregulation of Tnfα and toll receptor Tlr2. Notably, DEN-treated Hh-infected KO mice exhibited increased numbers of liver lobes with dysplasia and neoplasia and increased multiplicity of neoplasia, relative to similarly treated WT mice. Enhanced tumor promotion was associated with decreased hepatic expression of P450 enzymes Cyp2b10 and Cyp3a11, increased expression of Camp, and increased serum concentrations of chenodeoxycholic acid. Together, our findings suggest that liver tumor promotion is enhanced by an impaired metabolic detoxification of endobiotics and a persistent microbial-induced immune response.
    Cancer Research 02/2011; 71(7):2529-40. · 9.28 Impact Factor
  • Gastroenterology 01/2010; 138(5). · 12.82 Impact Factor
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    ABSTRACT: Diagnosis of chronic intestinal inflammation, which characterizes inflammatory bowel disease (IBD), along with prediction of disease state is hindered by the availability of predictive serum biomarker. Serum biomarkers predictive of disease state will improve trials for therapeutic intervention, and disease monitoring, particularly in genetically susceptible individuals. Chronic inflammation during IBD is considered distinct from infectious intestinal inflammation thereby requiring biomarkers to provide differential diagnosis. To address whether differential serum biomarkers could be identified in murine models of colitis, immunological profiles from both chronic spontaneous and acute infectious colitis were compared and predictive serum biomarkers identified via multivariate modeling. Discriminatory multivariate modeling of 23 cytokines plus chlorotyrosine and nitrotyrosine (protein adducts from reactive nitrogen species and hypochlorite) in serum and tissue from two murine models of colitis was performed to identify disease-associated biomarkers. Acute C. rodentium-induced colitis in C57BL/6J mice and chronic spontaneous Helicobacter-dependent colitis in TLR4(-/-) x IL-10(-/-) mice were utilized for evaluation. Colon profiles of both colitis models were nearly identical with chemokines, neutrophil- and Th17-related factors highly associated with intestinal disease. In acute colitis, discriminatory disease-associated serum factors were not those identified in the colon. In contrast, the discriminatory predictive serum factors for chronic colitis were neutrophil- and Th17-related factors (KC, IL-12/23p40, IL-17, G-CSF, and chlorotyrosine) that were also elevated in colon tissue. Chronic colitis serum biomarkers were specific to chronic colitis as they were not discriminatory for acute colitis. Immunological profiling revealed strikingly similar colon profiles, yet distinctly different serum profiles for acute and chronic colitis. Neutrophil- and Th17-related factors were identified as predictive serum biomarkers of chronic colitis, but not acute colitis, despite their presence in colitic tissue of both diseases thereby demonstrating the utility of mathematical modeling for identifying disease-associated serum biomarkers.
    PLoS ONE 01/2010; 5(10):e13277. · 3.53 Impact Factor