幽门螺杆菌对胃上皮细胞间隙连接超微结构的影响

通过实验和临床观察幽门螺杆菌(Helicobacter pylori)对胃上皮细胞间隙连接超微结构的影响，从细胞间隙连接角度探讨H. pylori致癌机制．将不同H. pylori菌株与BGC-823细胞共培养24 h或 48 h，用原位固定与原位包埋法透射电镜观察细胞间隙连接超微结构变化．对70例胃癌患者，用快速尿素酶试验、碱性品红染色和¹⁴C尿素呼气实验检测H. pylori，PCR法检测H. pylori CagA基因，及透射电镜观察胃上皮细胞间隙连接超微结构变化．结果显示，未加H. pylori组BGC-823细胞可见较多细胞连接及连接复合体，加H. pylori各组细胞的连接数、单位周长连接数与单位周长连接长度均小于未加H. pylori组，而细胞间隙最小宽度大于未加H. pylori组(P < 0.001或P < 0.005)，且CagA⁺ 的NCTC J99组、临床株GC 01组和NCTC 11639组细胞连接数、单位周长连接数均小于CagA^- 的NCTC 12908组(P < 0.001或P < 0.05)，NCTC J99组与临床株GC 01组细胞单位周长连接长度短于NCTC 12908组(P < 0.001)．胃癌患者H. pylori感染组细胞连接数、单位周长连接数与单位周长连接长度均小于无H. pylori感染组，细胞间隙最小宽度大于无H. pylori感染组(P < 0.001)，且CagA⁺ H. pylori感染者细胞连接数、单位周长连接数与单位周长连接长度均小于CagA^- H. pylori感染者，细胞间隙最小宽度大于CagA^- H. pylori感染者．上述结果表明，胃上皮细胞间隙连接改变与H. pylori感染，特别是CagA⁺ H. pylori感染有关．

Effect of Helicobacter pylori on cell gap junction ultrastructure of gastric epithelial cells

To observe the effect of Helicobacter pylori(H. pylori) on cell gap junction ultrastructure of gastric epithelial cells, and to explore carcinogenic mechanism of H. pylori from the changes of cell gap junction, BGC-823 cells were co-cultured with different H. pylori strains for 24 h and 48 h. The cell gap junction ultrastructure was observed under transmission electron microscope with sample preparation of fixation and embedding in situ. In 70 patients with gastric cancer(GC), H. pylori was detected by rapid urease test, basic fuchsin stain and ¹⁴C-urea breath test. The CagA gene of H. pylori was determined by PCR and the cell gap junction ultrastructure was observed under transmission electron microscope. More cell gap junctions and junction complexes of BGC-823 cells were found in control group without H. pylori. Groups with H. pylori had less number of cell gap junctions, less number of junctions/ unit perimeter, shorter length of junctions /unit perimeter, and bigger width of the intercellular space, comparing to control groups without H. pylori(P < 0.001 or P < 0.005). The number of cell junctions and the number of junctions/unit perimeter in the groups co-cultured with NCTC J99, GC 01 and NCTC 11639(CagA+) were less than that in the groups co-cultured with NCTC 12908(CagA^-) (P < 0.001 or P < 0.05), and the length of junctions/unit perimeter in the groups co-cultured with NCTC J99 and GC 01 was shorter than that in the groups co-cultured with NCTC 12908 (P < 0.001). In patients with GC, the number of cell junctions, the number of junctions/unit perimeter and the length of junctions/unit perimeter in group H. pylori infection were all less than those in group without H. pylori infection(P < 0.001), and that in CagA⁺ H. pylori group were less than that in CagA^- H. pylori group, but its smallest width of the intercellular space was longer than that in CagA^- H. pylori group. The above results showed that the changes of cell gap junction of gastric epithelial cells were associated with H. pylori infection especially CagA⁺ H. pylori infection.