Gastric ulcer and stomach aging: pathophysiology and clinical implications

The Development of Spasmolytic Polypeptide/TFF2-Expressing Metaplasia (SPEM) During Gastric Repair Is Absent in the Aged Stomach

BACKGROUND & AIMS

During aging, physiological changes in the stomach result in more tenuous gastric tissue that is less capable of repairing injury, leading to increased susceptibility to chronic ulceration. Spasmolytic polypeptide/trefoil factor 2-expressing metaplasia (SPEM) is known to emerge after parietal cell loss and during Helicobacter pylori infection, however, its role in gastric ulcer repair is unknown. Therefore, we sought to investigate if SPEM plays a role in epithelial regeneration.

METHODS

Acetic acid ulcers were induced in young (2-3 mo) and aged (18-24 mo) C57BL/6 mice to determine the quality of ulcer repair with advancing age. Yellow chameleon 3.0 mice were used to generate yellow fluorescent protein-expressing organoids for transplantation. Yellow fluorescent protein-positive gastric organoids were transplanted into the submucosa and lumen of the stomach immediately after ulcer induction. Gastric tissue was collected and analyzed to determine the engraftment of organoid-derived cells within the regenerating epithelium.

RESULTS

Wound healing in young mice coincided with the emergence of SPEM within the ulcerated region, a response that was absent in the aged stomach. Although aged mice showed less metaplasia surrounding the ulcerated tissue, organoid-transplanted aged mice showed regenerated gastric glands containing organoid-derived cells. Organoid transplantation in the aged mice led to the emergence of SPEM and gastric regeneration.

CONCLUSIONS

These data show the development of SPEM during gastric repair in response to injury that is absent in the aged stomach. In addition, gastric organoids in an injury/transplantation mouse model promoted gastric regeneration.

Gastric epithelial dysplasia and adenoma: historical review and histological criteria for grading

Gastric epithelial dysplasia (GED) hypothetically is a straight-forward concept: dysplastic epithelium replacing the normal gastric epithelium of the stomach. However, since its inception several decades ago, the term GED has become progressively complex and confusing because of differences in definitions and nomenclature that have been based on cytological, microscopic, endoscopic, or gross features. This has resulted in the terms "dysplasia," "adenoma," "flat adenoma," and "depressed adenoma." Some authors have also included reactive changes under the term "dysplasia."

Effect of colloidal bismuth subcitrate on age related gastric lesions in the rat

The purpose of this study was to determine the changes in rat gastric functional morphology that take place with age and to study the action of colloidal bismuth subcitrate on the age related degeneration of the stomach. At 95 weeks of age erosions were apparent over 80% of the gastric mucosa and this was associated with a significant decline in the numbers and mucus content of the mucosal epithelial cells. The rate of stem cell proliferation in the neck region was also significantly lower than that found in 9 week old animals. The administration of 50 mg/kg colloidal bismuth subcitrate for 14 days to 9 week old animals resulted in slight hypertrophy of the mucosal epithelial cells. When 95 week animals were placed on the same regimen there was a decline in the number of deep erosions in the mucosa and an increase in the number and mucin content of the mucosal epithelial cells. A significant increase in the proliferation of the stem cell population was also observed after colloidal bismuth subcitrate administration. It is suggested that colloidal bismuth subcitrate may ameliorate the increased susceptibility to harmful agents that occurs with age.