Rosa G. Liberman

Chemical and cytokine features of innate immunity characterize serum and tissue profiles in inflammatory bowel disease

Significance Our study investigates chemical damage associated with chronic inflammation and relates these macromolecular damage products to inflammatory bowel disease activity. Using mice as a model system, we show that chronic inflammatory responses that are common to mice and humans produce similar types and quantities of damage products in both species. Additional analysis of signaling molecules in the serum and tissue of diseased samples highlights the role of the innate immune response in the overall pathology of inflammatory bowel disease. 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.

Application of Liquid Chromatography-Accelerator Mass Spectrometry (LC-AMS) to Evaluate the Metabolic Profiles of a Drug Candidate in Human Urine and Plasma

Metabolite profiling of 100- and 1,000-fold diluted urine and plasma samples from a conventional radiolabeled human ADME study is described using a highly sensitive LC-AMS technique. The concentration of radioactivity and the metabolic profiles in urine and plasma determined using this technique were similar to those employing standard off-line (i.e. LSC) or in-line (i.e. beta-RAM or LC-ARC dynamic-flow) radioactivity monitoring techniques. The results indicate that at a simulated ca. 100 nCi clinical dose, plasma and urine concentrations of (14)C, as well as their metabolic profiles, may be determined routinely by LC-AMS. This approach opens the possibility of using LC-AMS for both the high-throughput quantitation of biological samples and the generation of high-resolution chromatographic profiles of complex mixtures at a lower cost than current AMS analyses that require the conversion of sample carbon to graphite, a laborious and time consuming process.

Integration of continuous-flow accelerator mass spectrometry with chromatography and mass-selective detection.

Physical combination of an accelerator mass spectrometry (AMS) instrument with a conventional gas chromatograph-mass spectrometer (GC/MS) is described. The resulting hybrid instrument (GC/MS/AMS) was used to monitor mass chromatograms and radiochromatograms simultaneously when (14)C-labeled compounds were injected into the gas chromatograph. Combination of the two instruments was achieved by splitting the column effluent and directing half to the mass spectrometer and half to a flow-through CuO reactor in line with the gas-accepting AMS ion source. The reactor converts compounds in the GC effluent to CO2 as required for function of the ion source. With cholesterol as test compound, the limits of quantitation were 175 pg and 0.00175 dpm injected. The accuracy achieved in analysis of five nonzero calibration standards and three quality control standards, using cholesterol-2,2,3,4,4,6-d6 as injection standard, was 100 +/- 11.8% with selected ion monitoring and 100 +/- 16% for radiochromatography. Respective values for interday precision were 1.0-3.2 and 22-32%. Application of GC/MS/AMS to a current topic of interest was demonstrated in a model metabolomic study in which cultured primary hepatocytes were given [(14)C]glucose and organic acids excreted into the culture medium were analyzed.

DNA adducts formed by a novel antitumor agent 11β-dichloro in vitro and in vivo

The multifunctional molecule 11β-dichloro consists of a ligand for the androgen receptor linked to a bifunctional alkylating group, permitting it to create DNA adducts that bind the androgen receptor. We propose that binding of the androgen receptor to 11β-DNA adducts acts to both shield damaged sites from repair and disrupt the expression of genes essential for growth and survival. We investigated the formation 11β-DNA adducts in tumor xenograft and nontumor tissues in mice. Using [14C]-11β-dichloro, we show that the molecule remains intact in blood and is widely distributed in mouse tissues after i.p. injection. Covalent 11β-guanine adducts identified in DNA that had been allowed to react with 11β-dichloro in vitro were also found in DNA isolated from cells in culture treated with 11β-dichloro as well as in DNA isolated from liver and tumor tissues of mice treated with the compound. We used accelerator mass spectrometry to determine the levels of [14C]-11β-DNA adducts in LNCaP cells treated in culture as well as in liver tissue and LNCaP xenograft tumors in treated mice. The level of DNA adducts in tumor tissue was found to be similar to that found in LNCaP cells in culture treated with 2.5 μmol/L 11β-dichloro. Our results indicate that 11β-dichloro has sufficient stability to enter the circulation, penetrate tissues, and form DNA adducts that are capable of binding the androgen receptor in target tissues in vivo. These data suggest the involvement of our novel mechanisms in the antitumor effects of 11β-dichloro. [Mol Cancer Ther 2006;5(4):977–84]

Abstract 2885: Features of innate immunity dominate serum and tissue protein and cytokine profiles in both mouse and human inflammatory bowel disease.

Proceedings: AACR 104th Annual Meeting 2013; Apr 6-10, 2013; Washington, DC Inflammatory bowel disease (IBD) is a chronic and relapsing intestinal inflammatory disease that arises through unknown genetic, environmental, and bacterial origins. Ulcerative colitis (UC) and Crohns disease (CD) are the two main forms of IBD, and their incidence is increasing in industrialized countries. Further, IBD is a significant risk factor for the development of colon cancer. Though the specific determinants remain elusive, persistent inflammation is believed to play a significant role in colon cancer carcinogenesis. To better define the molecular mechanisms linking colitis to the identity of disease biomarkers, we performed a translational comparison of protein expression and protein damage products in mouse and human IBD. Helicobacter hepaticus-infected Rag2-/- mice emulate many aspects of human IBD, and our recent work with this model highlights the importance of neutrophils in the pathology of colitis and colon cancer. Analysis of neutrophil- and macrophage-derived damage products revealed accumulation of 3-chlorotyrosine (CTyr) and 3-nitrotyrosine (NTyr) in inflamed mice colons that increased with disease duration. These results were further corroborated in mouse studies by histological evaluation, which demonstrated strong infiltration of neutrophils and macrophages to the site of inflammation. Human studies revealed an increase in CTyr in the colon of UC and CD tissues relative to serum levels. The nucleic acid chlorination damage product, 5-chloro-2′-deoxycytidine (5-Cl-dC), was quantified in human colon and found to be present at similar levels to that of inflamed mice colons. Multivariate analysis of these markers along with serum proteins and cytokines revealed a general signature of activated innate immunity in human IBD. UC sera were strongly suggestive of neutrophil activity while CD and mouse sera were suggestive of macrophage and neutrophil activity. These data point to innate immunity as a major determinant of serum and tissue profiles and provide insight into disease activity in IBD. Citation Format: Charles G. Knutson, Aswin Mangerich, Yu Zeng, Arkadiusz R. Raczynski, Rosa G. Liberman, Pilsoo Kang, Wenjie Ye, Guanyu Gong, Erin Prestwich, Kun Lu, John S. Wishnok, Joshua R. Korzenik, Gerald N. Wogan, James G. Gox, Peter C. Dedon, Steven R. Tannenbaum. Features of innate immunity dominate serum and tissue protein and cytokine profiles in both mouse and human inflammatory bowel disease. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 2885. doi:10.1158/1538-7445.AM2013-2885