Colonic expression of MUC2, MUC5AC, and TFF1 in inflammatory bowel disease in children.
BACKGROUND
The quantity and quality of mucins are affected in inflammatory bowel disease (IBD) both because of a reduction in the number of goblet cells and a decrease in the number of sugar residues per oligosaccharide side chain. Alteration in the types of mucins and aberrant location may contribute to the underlying pathology by affecting the mucus barrier function or may instead be a response to inflammation. The authors used the periodic acid-Schiff/Alcian blue stain to distinguish neutral and acidic mucins, and used specific antibodies to the mature goblet cell mucin MUC2, MUC2 core antigen, foveolar cell mucin MUC5AC, and gastric trefoil factor (TFF1), to characterize their presence and distribution in colonic tissue sections from patients with IBD.


RESULTS
Both core and mature MUC2 were expressed in all colonic goblet cells from patients with ulcerative colitis (UC) and Crohn disease and from healthy controls. MUC5AC and TFF1, which are not normally expressed by colonic tissue, also were expressed in scattered goblet cells, coexpressing with MUC2. In areas of goblet cell depletion, MUC2 was present in cytoplasmic granules of flattened, cuboidal, nongoblet-cell-like surface cells. The staining was more intense and homogenous with the MUC2 core antibody, suggesting expression of relatively immature mucin. Some of these cells also coexpressed MUC5AC but to a lesser extent. These findings are not unique to IBD but were also found in other types of intestinal inflammation.


CONCLUSIONS
The study confirms earlier observations that MUC2 is the major colonic mucin in IBD. It appears in two forms: mature MUC2 in goblet cells and immature MUC2 especially in secretory granules of cells that are not phenotypically goblet cells. MUC5AC and TFF1 expression in goblet cells is common in IBD and other inflammatory conditions of the colon. These changes may represent a nonspecific repair function of the colon cells to compensate for damage to barrier function.
Shaoul
Ron
R
Department of Pediatrics, Bnai Zion Medical Center, Faculty of Medicine, Technion--Israel Institute of Technology, Haifa, Israel. shaoul_r@012.net.il
Okada
Yoshio
Y
Cutz
Ernest
E
Marcon
Margaret A
MA
D000293:Adolescent; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D015212:Inflammatory Bowel Diseases / Q000378:metabolism* / Q000473:pathology; D008297:Male; D055271:Mucin 5AC; D055262:Mucin-2; D009077:Mucins / Q000378:metabolism*; D009124:Muscle Proteins; D009479:Neuropeptides; D010455:Peptides / Q000378:metabolism; D012720:Severity of Illness Index; D000071164:Trefoil Factor-2; D000071165:Trefoil Factor-3
C524625:MUC2 protein, human; C524678:MUC5AC protein, human; C524628:Muc2 protein, rat; C524680:Muc5ac protein, rat; D055271:Mucin 5AC; D055262:Mucin-2; D009077:Mucins; D009124:Muscle Proteins; D009479:Neuropeptides; D010455:Peptides; C099037:TFF3 protein, rat; D000071164:Trefoil Factor-2; D000071165:Trefoil Factor-3