幽门螺杆菌感染诱导胃粘膜环氧化酶-2表达

Helicobacter pylori infection induces cyclooxygenase-2 expression in gastric mucosa

目的探讨幽门螺杆菌(Hp)感染对胃粘膜环氧化酶-2(COX-2)表达的影响。方法27例无任何症状健康检查者,经胃镜采取胃窦部粘膜组织,用于Hp检测、病理组织学检查及免疫组织化学检查COX-2的表达。结果18例Hp感染者胃粘膜上皮细胞和炎症细胞表达COX-2,而9例Hp阴性者胃粘膜均不表达COX-2。结论Hp感染诱导胃粘膜COX-2表达。

Objective Adenocarcinoma of the stomach has been established as a consequence of gastric infection with Helicobacter pylori(H.pylori).The specific role of H.pylori in the pathogenesis is unknown yet.Recent studies indicate that expression of mitogen inducible cyclooxygenase-2(COX-2) occurs in gastrointestinal tumors.The purpose of the present study was to investigate expression of COX-2 protein in the human stomach with or without H.pylori infection.Methods Twenty-seven subjects who were asymptomatic referred to the hospital for healthy examination including endoscopic screening.Biopsy specimens were obtained from the subjects without any macroscopic lesions,such as peptic ulcer or gastric malignancies.H.pylori infection was determined by rapid urease test(CLO test),bacterial culture and histology(Giemsa staining).Expression of COX-2 was evaluated by immunohistochemistry using the avidin-biotin-peroxide complex(ABC) method The association between COX-2 expression and H.Pylori infection was assessed by Fisher's exact test.A P value less than 0.05 was considered to be statistically significant.Results specific immunostaining for COX-2 was observed in antral mucosa of 18 subjects infected with H.pylori COX-2 was expressed in gastric mucosal epithelia,mainly in the foveolar epithelial cells.Furthermore,COX-2 was also observed in the neck cells of the gastric glands and inflammatory mononuclear cells beneath the mucosal epithelia.Expression of COX-2 was never found in the gastric mucosa of H.pylori-negative subjects.A positive association of H.pylori infection with COX-2 expression was statistically significant(P< 0.001).Conclusion COX-2 expression has been reported in gastrointestinal carcinormas,gastrointestinal cancer cell-line,and in the gut after carcinogenic treatment.The present study demonstrates that H.pylori infection induces COX-2 expression in human gastric mucosa,indicating the enzyme or some factors related to H.pylori possibly involved in the pathogenesis of gastric lesions in humans.