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Background: Mycobacterium avium subsp. paratuberculosis infected animals show a variety of granulomatous lesions, from focal forms with well-demarcated granulomas restricted to the gut-associated lymphoid tissue (GALT), that are seen in the initial phases or latency stages, to a diffuse granulomatous enteritis, with abundant (multibacillary) or scant (paucibacillary) bacteria, seen in clinical stages. Factors that determine the response to the infection, responsible for the occurrence of the different types of lesion, are still not fully determined. It has been seen that regulatory T cells (Treg) play an important role in various diseases where they act on the limitation of the immunopathology associated with the immune response. In the case of paratuberculosis (PTB) the role of Treg lymphocytes in the immunity against Map is far away to be completely understood; therefore, several studies addressing this subject have appeared recently. The aim of this work was to assess, by immunohistochemical methods, the presence of Foxp3+ T lymphocytes in intestinal samples with different types of lesions seen in cows with PTB. Methods: Intestinal samples of twenty cows showing the different pathological forms of PTB were evaluated: uninfected controls (n = 5), focal lesions (n = 5), diffuse paucibacillary (n = 5) and diffuse multibacillary (n = 5) forms. Foxp3+ lymphocyte distribution was assessed by differential cell count in intestinal lamina propria (LP), gut-associated lymphoid tissue (GALT) and mesenteric lymph node (MLN). Results: A significant increase in the number of Foxp3+ T cells was observed in infected animals with respect to control group, regardless of the type of lesion. However, when the different categories of lesion were analyzed independently, all individuals with PTB lesions showed an increase in the amount of Foxp3+ T lymphocytes compared to the control group but this increase was only significant in cows with focal lesions and, to a lesser extent, in animals with diffuse paucibacillary forms. The former showed the highest numbers, significantly different from those found in cows with diffuse lesions, where no differences were noted between the two forms. No specific distribution pattern was observed within the granulomatous lesions in any of the groups. Conclusions: The increase of Foxp3+ T cells in focal forms, that have been associated with latency or resistance to infection, suggest an anti-inflammatory action of these cells at these stages, helping to prevent exacerbation of the inflammatory response, as occurs in diffuse forms, responsible for the appearance of clinical signs. [ABSTRACT FROM AUTHOR]

Inflammatory bowel disease (IBD) develops through complex interplay of genetic, microbial, immune, and environmental factors. Trace elements alterations are commonly present in IBD and may have influence on IBD development. Heavy metal pollution is one of the major environmental issues nowadays and IBD incidence is rising in countries where industry starts to develop. Metals are implicated in processes that are connected to IBD pathogenesis. The aim of this study was to investigate toxic and trace element levels in pediatric population of IBD patients both in serum and intestinal mucosa. This prospective study enrolled children newly diagnosed with IBD in University children's hospital in Belgrade. Concentrations of thirteen elements: Al, As, Ca, Cd, Cr, Cu, Fe, K, Mg, Mn, Na, Se and Zn in serum and intestinal mucosa of 17 newly diagnosed children with IBD (10 Crohn's disease (CD) and 7ulcerative colitis (UC)) and 10 controls were assessed using inductively coupled plasma mass spectrometry (ICP-MS). Intestinal mucosa samples were taken from terminal ileum and six different colon segments (cecum, ascending colon, colon transversum, descending and sigmoid colon and rectum). The results demonstrated significant alterations in serum and intestinal mucosa concentrations of investigated elements. Serum iron was significantly decreased in IBD and CD group, compared to controls while serum Cu significantly differed between three investigated groups with highest concentration observed in CD children. Serum manganese was the highest in the UC subgroup. Terminal ileums of IBD patients contained significantly lower amount of Cu, Mg, Mn and Zn with Mn being significantly decreased also in CD patients compared to control. IBD patients' caecum contained significantly less Mg and Cu while colon transversum tissue samples from IBD and Crohn's patients contained significantly more chromium than controls. Moreover, sigmoid colon of IBD patients were poorer in Mg than controls (p < 0.05). Colon Al, As and Cd were significantly reduced in IBD, and UC children compared to control. Correlations of investigated elements in CD and UC groups were different from controls. Biochemical and clinical parameters showed correlation with element concentrations in intestines. Sera of CD, UC and control children significantly differ in Fe, Cu and Mn levels. Serum manganese was the highest in the UC subgroup creating the most prominent and only significant difference between UC and CD subgroups. Terminal ileum of IBD patients contained significantly lower amount of majority of investigated essential trace elements and toxic elements were significantly reduced in colon of IBD and UC patients. Investigation of macro- and microelement alterations in children and adults has potential to further elucidate IBD pathogenesis. [ABSTRACT FROM AUTHOR]

Lin Z, Hegarty JP, Cappel JA, Yu W, Chen X, Faber P, Wang Y, Kelly AA, Poritz LS, Peterson BZ, Schreiber S, Fan J-B, Koltun WA. Identification of disease-associated DNA methylation in intestinal tissues from patients with inflammatory bowel disease. Overwhelming evidence supports the theory that inflammatory bowel disease (IBD) is caused by a complex interplay between genetic predispositions of multiple genes, combined with an abnormal interaction with environmental factors. It is becoming apparent that epigenetic factors can have a significant contribution in the pathogenesis of disease. Changes in the methylation state of IBD-associated genes could significantly alter levels of gene expression, potentially contributing to disease onset and progression. We have explored the role of DNA methylation in IBD pathogenesis. DNA methylation profiles (1505 CpG sites of 807 genes) of matched diseased ( n = 26) and non-diseased ( n = 26) intestinal tissues from 26 patients with IBD [Crohn's disease (CD) n = 9, ulcerative colitis (UC) n = 17] were profiled using the GoldenGate™ methylation assay. After an initial identification of a panel of 50 differentially methylated CpG sites from a training set (14 non-diseased and 14 diseased tissues) and subsequent validation with a testing set (12 non-diseased and 12 diseased tissues), we identified seven CpG sites that are differentially methylated in intestinal tissues of IBD patients. We have also identified changes in DNA methylation associated with the two major IBD subtypes, CD and UC. This study reports IBD-associated changes in DNA methylation in intestinal tissue, which may be disease subtype-specific. [ABSTRACT FROM AUTHOR]