Correlation of ex vivo cytokine secretion profiles with scoring indices in ulcerative colitis.

BACKGROUND: In ulcerative colitis, the complexity of mucosal cytokine secretion profiles and how they correlate with endoscopic and clinical scores is still unclear. METHODS: In this study, we collected fresh biopsies from UC patients to investigate which cytokines are produced in ex vivo culture conditions, a platform increasingly used for testing of novel drugs. Then, we correlated cytokine production with several scoring indices commonly used to assess the severity of the disease. RESULTS: Increased levels of IL-1ß, IL-2, IL-4, IL-6, IL-8, IL-10, IL-12, IL-13, TNFα and IFNÉ£ were produced by biopsies of UC patients compared to non-IBD controls. Our results show a better correlation of cytokine levels with Mayo Endoscopic Subscore (MES) and Mayo score, than the more complex Ulcerative Colitis Endoscopic Index of Severity (UCEIS). Out of 10 measured cytokines, eight correlated with MES, six with Mayo score and only three with UCEIS, due to the partial increase in cytokine secretion observed in donors with UCEIS = 7-8. When we analysed individual subscores within the UCEIS, Vascular Network subscore showed a correlation similar to MES (7/10 cytokines), while Bleeding as well as Erosions and Ulcers subscores correlated with only 3/10 cytokines, similarly to the total UCEIS. CONCLUSIONS: Our findings suggest that choosing biopsies from donors with MES = 2-3 and UCEIS = 2-6 from areas with no bleeding and no superficial and/or deep ulcers could enable a deeper insight into the cytokine profile of the inflamed tissue and represent a better tool for studying potential therapeutic targets and evaluation of novel therapies.

Claudins: Beyond Tight Junctions in Human IBD and Murine Models.

Claudins are transmembrane proteins constituting one of three tight junction protein families. In patients with inflammatory bowel disease (IBD), disease activity-dependent changes in expression of certain claudins have been noted, thus making certain claudin family members potential therapy targets. A study was undertaken with the aim of exploring expression of claudins in human disease and two different animal models of IBD: dextrane sulfate sodium-induced colitis and adoptive transfer model of colitis. The expression of sealing claudin-1, claudin-3, claudin-4, and claudin-8, and pore-forming claudin-2 in humans and rodents has been evaluated by immunohistochemistry and quantitative polymerase chain reaction. Claudins were expressed by epithelial and cells of mesodermal origin and were found to be situated at the membrane, within the cytoplasm, or within the nuclei. Claudin expression by human mononuclear cells isolated from lamina propria has been confirmed by Western blot and flow cytometry. The claudin expression pattern in uninflamed and inflamed colon varied between species and murine strains. In IBD and both animal models, diverse alterations in claudin expression by epithelial and inflammatory cells were recorded. Tissue mRNA levels for each studied claudin reflected changes within cell lineage and, at the same time, mirrored the ratio between various cell types. Based on the results of the study, it can be concluded that 1) claudins are not expressed exclusively by epithelial cells, but by certain types of cells of mesodermal origin as well; 2) changes in the claudin mRNA level should be interpreted in the context of overall tissue alterations; and 3) both IBD animal models that were analyzed can be used for investigating claudins as a therapy target, respecting their similarities and differences highlighted in this study.

Modulation of urokinase plasminogen activator system by poly(ADP-ribose)polymerase-1 inhibition.

The urokinase plasminogen activator (uPA) system is a complex regulator of extracellular proteolysis which is involved in various physiological and pathological processes. The major components of this system are the serine protease uPA, two inhibitors PAI-1 and PAI-2, and the receptor uPAR. It has been previously shown by several groups that the uPA system has an important role in cancer progression and therefore its possible prognostic and therapeutic value has been evaluated. The aim of this study is to tackle the role of poly(ADP-ribosyl)ation in the induction of uPA activity in a glioblastoma cell line, A1235. This cell line is sensitive to alkylation damage and is a model for drug treatment. The components of the uPA system and the level of DNA damage were analyzed after alkylation agent treatment in combination with poly(ADP-ribose)polymerase-1 (PARP-1) inhibition. Here we show that the increase in uPA activity results from the net balance change between uPA and its inhibitor at mRNA level. Further, PARP-1 inhibition exerts its influence on uPA activity through DNA damage increase. Involvement of several signaling pathways, as well as cell specific regulation influencing the uPA system are discussed.