东亚型CagA^+幽门螺杆菌感染与不同胃黏膜病变中凋亡蛋白表达的关系

Relationship between East Asian CagA^+ Helicobacter pylori infection and expression of apoptosis protein in different gastric mucosal lesions

目的通过观察幽门螺杆菌(Helicobacter pylori,Hp)及其东亚型CagA+菌株在西安地区不同胃黏膜病变中的感染情况及其对胃黏膜中凋亡蛋白Bax、Bcl-2、Fas及caspase-3表达的影响,以探讨其在胃癌发生发展中的作用。方法在西安地区通过内镜获取不同胃黏膜病变的胃黏膜组织并经HE染色病理确诊。其中包括浅表性胃炎(chronic superficial gastritis,CSG)、萎缩性胃炎(chronic atrophic gastritis,CAG)、萎缩性胃炎伴不典型增生(chronic atrophic gastritis with dysplasia,Dys)、胃癌(gastric cancer,GC)。用快速尿素酶试验及免疫组织化学方法检测Hp及东亚型CagA+菌株感染情况;用免疫组化方法分别检测各组中凋亡蛋白Bax、Bcl-2、Fas、caspase-3的表达情况。结果①西安地区Hp及东亚型CagA+菌株感染在胃癌中最高,在慢性浅表性胃炎中最低,差异有统计学意义(P<0.05);②Hp(+)组中Bax、Fas表达率高于Hp(-)组(P<0.05),东亚型CagA+Hp感染组Bax、Fas、caspase-3表达率高于非东亚型CagA+Hp感染组(P<0.05),而Bcl-2表达率低于非东亚型CagA+HP感染组(P<0.05);③在CAG组、Dys组、GC组中,Bax、Fas、caspase-3表达率逐渐减低,Bcl-2表达率逐渐升高。结论西安地区以东亚型CagA+菌株感染为主,东亚型CagA+Hp感染后,促进胃黏膜上皮细胞凋亡,与其他多种因素共同作用,最终导致胃癌的发生。

Objective To observe Helicobacter pylori （Hp） and CagA^＋-East Asian strains infection in different gastric mucosal lesions in Xi＇an, and the influence of the infection on the expression of apoptosis proteins （Bax, Bcl-2, Fas and caspase-3） in different gastric mucosa lesions to elucidate the mechanism of gastric carcinogenesis related to Hp and CagA^＋-East Asian strains infection. Methods Gastric mucosal tissues were taken from patients with different gastric mucosal lesions in Xi＇an. Confirmed by HE staining, including chronic superficial gastritis （CSG）, chronic atrophic gastritis （CAG）, chronic atrophic gastritis with dysplasia （Dys）, and gastric cancer （GC）. Hp infection and CagA^＋-East Asian strains infection were detected by fast urease test and immunohistochemical method. Expressions of Bax, Bcl-2, Fas and caspase-3 in each group were determined using immunohistochemical method. Results ① The infection rate of Hp and CagA^＋-East Asian strains was the highest in GC group and the lowest in CSG group （P〈0.05）. ② The expressions of Bax and Fas were significantly higher in Hp（＋） group than in Hp（-） group （P〈0.05）. The expressions of Bax, Fas and caspase-3 were significantly higher in CagA^＋-East Asian Hp infection group than in non-CagA^＋-East Asian Hp infection group （P〈0.05）. However, Bcl-2 expression was lower than that in non-CagA^＋-East Asian Hp infection group （P〈0.05）. ③ The expressions of Bax, Fas and caspase-3 gradually decreased in CAG, Dys and GC groups, but Bcl-2 expression gradually increased. Conclusion Xi＇an is an area with high Hp infection, and the majority of HP-infected persons carry East Asian CagA^＋ strains. East Asian CagA^＋ Hp infection can induce apoptosis of gastric mucosa epithelium and ultimately leads to gastric cancer when working with other factors.