Unique membranous gastrin receptor expression of parietal cells and its distribution pattern in the gastric oxyntic mucosa and fundic gland polyps

• Published in: Human pathology 2022-07, Vol.125, p.23-34
• Main Authors: Sato, Yoko, Ban, Shinichi, Katayama, Yasumi, Mitsui, Takashi
• Format: Article
• Language: English
• Subjects: Antibodies; Cancer; Cloning; Fundic gland polyp; Gastrin receptor; Histamine; Hyperplasia; Immunohistochemistry; Kinases; Oxyntic mucosa; Peptides; Proteins; Proton pump inhibitor; Stomach
• ISSN: 0046-8177; 1532-8392
• DOI: 10.1016/j.humpath.2022.04.001

The aim of this study was to clarify the correlation between gastrin receptor (GR) expression in the gastric oxyntic mucosa and fundic gland polyps (FGPs) and the histological and immunohistochemical findings of the mucosa as well as the history of proton pump inhibitor (PPI) administration. The unique membranous linear positivity of GR in parietal cells was reproducibly observed by immunohistochemistry, which was also validated by immunofluorescence. Further histological and immunohistochemical examination of 34 oxyntic mucosae and 43 FGPs revealed the following: 1) parietal cells (PCs) with membranous linear GR expression (mGR) were observed to be limited to the isthmus-neck region in the normal state; 2) appearance of PCs with mGR in the deep oxyntic gland regions was significantly related to the PPI medication history; 3) PCs with mGR were more frequently observed in the deep oxyntic gland regions when the oxyntic mucosa showed derangement of mucosal component cell compartmentalization revealed by MUC5AC and MUC6 immunohistochemistry, which was also significantly related to the PPI use; and 4) PCs with intense membranous linear positivity of GR were observed to be diffusely distributed in all of the cases of FGPs. In conclusion, the distribution of unique GR membranous linear expression in PCs of the oxyntic mucosa under PPI medication and FGPs could reflect the pathologic mucosal state characterized by derangement of the compartmentalization of mucosal component cells, which could be another basis for evaluating physiologic and/or pathophysiologic conditions of the gastric mucosa. •Unique membranous linear gastrin receptor (GR) expression is observed in parietal cells (PCs) of gastric oxyntic mucosa.•The PCs with membranous linear GR expression are limited to the isthmus-neck region in normal oxyntic gland mucosa.•Their distribution pattern is related to the PPI medication and deranged component cell organization of the mucosa.•The PCs with membranous linear GR expression are distributed diffusely in gastric fundic gland polyps.•The GR expression status could be another basis for evaluating pathophysiologic conditions of the gastric oxyntic mucosa.