Immunohistochemistry of gap junctions in normal and diseased gastric mucosa of humans

Abstract

Background & Aims Intercellular communication through gap junctions has been proposed to be an important mechanism for the maintenance of tissue homeostasis. However, few studies have considered the role of gap junctions in gastric mucosa. The purpose of this study was to evaluate the distribution of gap junction-specific proteins in normal and diseased gastric mucosa of humans. Methods Biopsy specimens were obtained endoscopically. Immunohistochemical staining was performed by standard immunoperoxidase techniques using an anti-connexin 32 monoclonal antibody. Results In normal gastric mucosa, connexin 32 was present chiefly in the foveolar cells and in a decreasing staining gradient extending down to the necks of the glands. Connexin 32 also was observed in the epithelial cells of atrophic mucosa in a pattern similar to that observed in normal controls. Conversely, the majority of the foveolar cells adjacent to erosions had reduced or absent staining. Connexin 32 also was reduced significantly or absent from metaplastic epithelial cells. No malignant cells from patients with carcinoma contained detectable connexin 32. Conclusions Intercellular communication likely is impaired in precancerous or paracancerous lesions of the stomach. Abnormal intercellular communication thus may play an important role in the progression from mucosal injury to intestinal metaplasia and/or gastric carcinoma.