Gastric corpus mucin expression after partial gastrectomy, in relation to colonization with Helicobacter pylori

Twelve different genes for mucin have been described. MUC5AC and MUC6 encode the secreted apomucins of the stomach. A gradient from the surface epithelium (foveola) to the glands is typical for MUC5AC synthesis, whereas a gradient in the opposite direction was found for MUC6. Our goal was to determine the distribution of MUC5AC and MUC6 in the postoperative stomach, with relation to the H. pylori status. Gastric corpus biopsy specimens from patients who underwent partial gastrectomy were examined by immunohistochemistry for mucin gene (MUC5AC and MUC6) apoproteins. We used polyclonal antibodies for amino acid tandem repeats of both proteins. A scoring system (0-3) was used to assess staining intensity at four sites: the lumen, the foveola, the mucous neck cells, and the glands. Helicobacter pylori status was determined by histology and rapid urease test and was considered positive or negative when both tests were positive or negative, respectively. We studied 19 H. pylori-positive and 32 H. pylori-negative patients. No significant change in MUC5AC or MUC6 synthesis and secretion was demonstrated between H. pylori-positive or -negative patients. A gradient similar to that shown for the intact stomach (from the surface epithelium to the glands) for MUC5AC protein and an increase of MUC6 protein presentation from the mucous neck cell to the glands were demonstrated. The pattern of MUC5AC protein synthesis was not different between H. pylori-positive and -negative patients in the postoperative stomach. MUC6 expression was higher in the foveola in H. pylori-positive patients, whereas there was no difference in the other cell layers.