Ulcerative colitis (UC) is a chronic, relapsing inflammatory condition of the gastrointestinal tract with a complex genetic and environmental etiology. We performed two distinct UC genome-wide association (GWA) studies, and analyzed these jointly with a previously published scan1, comprising, in aggregate, 2,693 patients with UC and 6,791 controls. A total of 59 SNPs from 14 independent loci attained P < 10−5. Seven of these loci exceeded genome-wide significance (P < 5 × 10−8). After testing an independent cohort of 2009 patients with UC and 1580 controls, 14 loci were significantly associated, including novel UC associations with FCGR2A, 5p15, 2p16, CARD9 and ORMDL3. In our study we confirmed association with 14 previously identified UC susceptibility loci, while an analysis of acknowledged Crohn's disease (CD) loci showed that roughly half of known CD associations are shared with UC. These data implicate approximately 30 loci for UC, providing novel insights into disease pathogenesis.
The role of cytokines in the accumulation of eosinophil granulocytes in inflamed tissue has been studied extensively during recent years, and these molecules have been found to participate throughout the whole process of eosinophil recruitment. Haematopoietic cytokines such as IL‐3, IL‐5 and GM‐CSF stimulate the proliferation and differentiation of eosinophils in the bone marrow, and the release of mature eosinophils from the bone marrow into the blood is probably promoted by IL‐5. Priming of eosinophils in the blood following, for example, allergen challenge is performed mainly by IL‐3, IL‐5 and GM‐CSF. An important step in the extravasation of eosinophils is their adhesion to the vascular endothelium. Adhesion molecules are upregulated by, e.g. IL‐1, IL‐4, TNF‐α and IFN‐γ and the same cytokines may also increase the affinity of adhesion molecules both on eosinophils and endothelial cells. Finally, a number of cytokines have been shown to act as eosinophil chemotactic factors, attracting the cells to the inflammatory focus in the tissue. Some of the most important eosinophil chemoattractant cytokines are IL‐5, IL‐8, RANTES, eotaxin, eotaxin‐2, eotaxin‐3, MCP‐3, MCP‐4 and TNF‐α. Th2 cells, mast cells and epithelial cells are important sources of proinflammatory cytokines, but in recent years, the eosinophils have also been recognized as cytokine‐producing and thereby immunoregulatory cells. The aim of this paper is to review the role of cytokines in the process of eosinophil recruitment in asthma, allergy and ulcerative colitis.
A 45 kDa-protein was purified from the granules of human neutrophils. The protein consists of two apparently identical subunits. The isoelectric point was pH 8.40, and the molecular weight 45 kDa (unreduced) or 24 kDa (reduced). Treatment of the protein with Endoglucosidase F resulted in a reduction in the molecular weight to 20 kDa, indicating the presence of N-linked carbohydrate. The extinction coeffient was E1%,1cm = 13.76 at 280 nm. The 60 amino acid sequence revealed up to 65% sequence homology with rat alpha 2-microglobulin-related protein, which belongs to the lipocalin family. The protein co-sedimented with secondary (specific) granule marker proteins and correlated to the neutrophil content of Lactoferrin (r = 0.81, p < 0.001) and was estimated to be 0.59 microgram 10(-6) cells. Release studies showed that the neutrophils released 51.4 +/- 9.0% of the total cellular content of the protein when they were exposed to serum-opsonized particles, which was much higher than the release of Myeloperoxidase (12.7 +/- 3.5%) and Lactoferrin (22.9 +/- 4.7%). The N-terminal and four tryptic fragment amino acid sequence of the protein was identical with an N-formyl peptide binding 24 kDa protein and gelatinase associated protein of human neutrophils. In conclusion, we have purified and characterized a protein, human neutrophil lipocalin (HNL), from the secondary granules of human neutrophils and shown that it is readily mobilized from the neutrophils upon stimulation.
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