alpha-Neup5Ac-(2--3)-beta-D-Galp-(1--4)-[alpha-L-Fucp-(1--3)]-D-GlcpNAc and Colitis--Ulcerative

Lymphocyte homing is mediated by a cascade of adhesive interactions between circulating lymphocytes and specialized endothelial cells comprising high endothelial venules (HEVs). Sulfated O-glycans expressed on HEVs, collectively called peripheral lymph node addressin (PNAd), interact with L-selectin expressed on lymphocytes, contributing to the initial step of the lymphocyte homing. In chronic inflammatory states, PNAd is induced on HEV-like vessels but absent in non-lymphoid tissues under normal conditions. Such HEV-like vessels have been observed in various chronic inflammatory diseases including rheumatoid arthritis, lymphocytic thyroiditis, Helicobacter pylori-associated chronic gastritis, and inflammatory bowel disease (IBD), and implicated in lymphocyte recruitment in those diseases. In H. pylori-associated chronic gastritis, PNAd-expressing HEV-like vessels are induced, and the progression of chronic inflammation is highly correlated with appearance of these vessels. Furthermore, eradication of H. pylori by antibiotics resulted in disappearance of PNAd. These results indicate that inhibition of PNAd formation could have therapeutic effect by attenuating lymphocyte recruitment. In ulcerative colitis (UC), PNAd-expressing HEV-like vessels are induced, preferentially in the active phase, and T cells, particularly CD4(+) T cells, are closely associated with these vessels, suggesting that T cell recruitment via PNAd-expressing HEV-like vessels plays at least a partial role in UC pathogenesis. Additionally, N-acetylglucosamine-6-O-sulfotransferase 1 (GlcNAc6ST-1) is suggested to be a candidate to regulate PNAd induction on HEV-like vessels in UC. These results provide a potential therapeutic strategy to treat UC by blocking T cell adhesion to PNAd-expressing HEV-like vessels. Inhibition or down-regulation of GlcNAc6ST-1 may be an alternative.

Topics: Antigens, Surface; Chronic Disease; Colitis, Ulcerative; Endothelial Cells; Gastritis; Helicobacter Infections; Helicobacter pylori; Humans; L-Selectin; Lewis X Antigen; Membrane Proteins; Oligosaccharides; Polysaccharides; Receptors, Lymphocyte Homing; Sialyl Lewis X Antigen; Venules

Ulcerative colitis (UC) is a chronic inflammatory disease histologically characterized by diffuse mononuclear cell infiltrates in colonic mucosa. These inflammatory cells are considered to be recruited via high endothelial venule (HEV)-like vessels displaying mucosal addressin cell adhesion molecule 1 (MAdCAM-1), the ligand for α4β7 integrin, and/or peripheral lymph node addressin (PNAd), an L-selectin ligand. 6- O-sulfation of N-acetylglucosamine in the carbohydrate moiety of PNAd is catalyzed exclusively by N-acetylglucosamine-6- O-sulfotransferase 1 (GlcNAc6ST-1) and GlcNAc6ST-2. To determine the role of 6- O-sulfation of N-acetylglucosamine on HEV-like vessels in UC, we used a chronic dextran sulfate sodium-induced colitis model using mice deficient in both GlcNAc6ST-1 and GlcNAc6ST-2. We found that more inflammatory cells, with expression of tumor necrosis factor α, were infiltrated in double knockout mouse colitis compared with that in wild-type mice. Moreover, the number of MAdCAM-1-positive vessels was increased in double knockout mouse colitis, and these vessels were bound by E-selectin•IgM chimeras that bind to unsulfated sialyl Lewis X (sLeX). These findings suggest that interactions between MAdCAM-1 and α4β7 integrin and/or unsulfated sLeX and L-selectin may become a dominant mechanism for inflammatory cell recruitment in the absence of 6-sulfo sLeX and contribute to more severe colitis phenotypes seen in double knockout mice.

Topics: Animals; Carbohydrate Sulfotransferases; Cell Adhesion Molecules; Colitis, Ulcerative; Colon; Disease Models, Animal; Gene Deletion; Immunohistochemistry; Intestinal Mucosa; L-Selectin; Male; Mice, Inbred C57BL; Mice, Knockout; Mucoproteins; Oligosaccharides; Sialyl Lewis X Antigen; Sulfotransferases; Venules

A diffuse lymphocyte infiltrate is 1 of the characteristic features of ulcerative colitis (UC). Such lymphocyte recruitment requires lymphocyte rolling mediated by L-selectin ligand carbohydrates (6-sulfo sialyl Lewis X-capped O-glycans) and/or mucosal addressin cell adhesion molecule 1 (MAdCAM-1) expressed on high endothelial venule (HEV)-like vessels. The present study was undertaken to elucidate the role of MAdCAM-1 posttranslationally modified ("decorated") with L-selectin ligand carbohydrates in UC pathogenesis and consequent clinical outcomes.. Biopsy specimens composed of active and remission phases of UC as well as normal colonic mucosa were immunostained for CD34, MAdCAM-1, and MECA-79, and the immunostained sections were quantitatively analyzed. Reverse-transcriptase polymerase chain reaction (RT-PCR) was carried out to evaluate transcripts of MAdCAM-1 and N-acetylglucosamine-6-O-sulfotransferases (GlcNAc6STs). CHO and Lec2 cells transfected with CD34 and MAdCAM-1 together with enzymes involved in L-selectin ligand carbohydrate biosynthesis were analyzed by immunofluorescence, FACS, and Western blotting to characterize the biochemical properties of GlcNAc6STs.. The number of MAdCAM-1(+) vessels was increased in UC, with no significant difference between active and remission phases. An increased ratio of MECA-79(+) to MAdCAM-1(+) vessels with preferential GlcNAc6ST-1 transcripts was observed in the active phase of UC compared to the remission phase. MAdCAM-1 protein was colocalized with L-selectin ligand carbohydrates at the luminal surface of HEV-like vessels in situ. GlcNAc6ST-1 preferentially utilizes MAdCAM-1 as a scaffold protein for GlcNAc-6-O-sulfation in L-selectin ligand carbohydrate biosynthesis.. UC disease activity is not regulated by expression of MAdCAM-1 protein itself, but rather by GlcNAc6ST-1-mediated decoration of MAdCAM-1 protein with L-selectin ligand carbohydrates.

Topics: Animals; Antigens, Surface; Blotting, Western; Carbohydrate Sulfotransferases; Case-Control Studies; Cell Adhesion Molecules; CHO Cells; Colitis, Ulcerative; Cricetinae; Cricetulus; Fluorescent Antibody Technique; Humans; Immunoenzyme Techniques; Immunoglobulins; L-Selectin; Ligands; Membrane Proteins; Mucoproteins; Oligosaccharides; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Sialyl Lewis X Antigen; Sulfotransferases

The pathogenic significance of cell adhesion molecules (CAMs) in ulcerative colitis (UC) is largely unknown. Colonic expression of E-selectin, sialyl Lewis X (sLe(x)), and macrophage inflammatory protein-1x (MIP-1alpha) as well as serum concentrations of E-selectin and MIP-1alpha in UC were studied. Thirty patients with UC, 10 patients with irritable bowel syndrome, and 10 healthy subjects were included. Colonic biopsies were stained immunohistochemically, and blood concentrations were measured with an ELISA technique. Soluble E-selectin did not correlate with diagnosis or disease activity. MIP-1alpha was below the detection limit. Epithelial cells expressed all three molecules, both on surface membranes and intracellularly. sLe(x) staining was weaker (P = 0.0002) and MIP-1alpha staining stronger (P = 0.014) in UC patients than in controls. Leukocyte MIP-alpha staining correlated with diagnosis (P = 0.021), sLe(x) staining (P = 0.023), and colonoscopy (P = 0.018). It is shown that E-selectin, sLe(x), and MIP-1alpha are synthesized and expressed by epithelial cells, indicating that CAMs are not only involved in leukocyte extravasation and migration, but also in the interaction between leukocytes and colonic epithelium. This knowledge might contribute to the development of improved treatments in UC.

Topics: Adult; Case-Control Studies; Chemokine CCL3; Chemokine CCL4; Colitis, Ulcerative; Colon; Colonic Diseases, Functional; E-Selectin; Enzyme-Linked Immunosorbent Assay; Epithelial Cells; Female; Humans; Intestinal Mucosa; Leukocytes; Lewis X Antigen; Macrophage Inflammatory Proteins; Male; Oligosaccharides; Sialyl Lewis X Antigen