通过根除幽门螺杆菌进行化学预防的可能性：幽门螺杆菌感染中的氧化性DNA损伤与细胞凋亡

Possibility of chemoprevention by the eradication of Helicobacter pylori: oxidative DNA damage and apoptosis in H. pylori infection.

作者信息

Hahm K B, Lee K J, Choi S Y, Kim J H, Cho S W, Yim H, Park S J, Chung M H

机构信息

Department of Gastroenterology and Anatomic Pathology, Ajou University School of Medicine, Suwon, Korea.

出版信息

Am J Gastroenterol. 1997 Oct;92(10):1853-7.

PMID:9382051

Abstract

OBJECTIVES

The purpose of this study was to study the changes of 8-hydroxydeoxyguanosine (8-OH-dG) contents of DNA from human gastric mucosa with or without Helicobacter pylori and the changes of two biomarkers, iNOS and apoptosis, in gastric biopsies obtained before and after the eradication of H. pylori.

METHODS

DNA isolated from the biopsied human gastric mucosa was digested to deoxynucleotides by nuclease P1, then with Escherichia coli alkaline phosphatase, and analyzed by HPLC-ECD system. 8-OH-dG content was expressed as the number of residues per 10(5) deoxyguanosine. iNOS immunohistochemical staining was performed with antihuman iNOS antiserum generated in mice at a dilution of 1:500, and in situ apoptosis was detected by in situ terminal deoxyribonucleotide transferase (TdT)-mediated dUTP nick end labeling. Both the density of H. pylori and the degree of inflammation were scored.

RESULTS

The 8-OH-dG contents of healthy normal controls with negative H. pylori were 4.31 +/- 2.33 (8-OH-dG/10(5) dG), whereas those of patients with positive H. pylori were 10.40 +/- 7.25. The difference between these two values was statistically significant (p < 0.01). The 8-OH-dG contents were significantly decreased after the eradication of H. pylori (12.22 +/- 2.09 vs. 2.42 +/- 1.22, p < 0.001). After the eradication of H. pylori, both the apoptotic index and the iNOS scores were significantly decreased, compared with those before eradication (3.72 +/- 1.74 vs. 1.17 +/- 1.06 for apoptosis and 10.34 +/- 6.79 vs. 1.43 +/- 1.14 for iNOS, p < 0.001). Statistically significant correlations were observed among apoptotic index, iNOS score, degree of inflammation, and density of H. pylori (p < 0.05).

CONCLUSIONS

The increased levels of oxidative DNA damage, increased occurrences of apoptosis, and increased expressions of iNOS suggest mechanistic links between H. pylori infection and gastric carcinogenesis.

摘要

目的

本研究旨在探讨幽门螺杆菌（Helicobacter pylori，H. pylori）感染与否的人胃黏膜DNA中8-羟基脱氧鸟苷（8-hydroxydeoxyguanosine，8-OH-dG）含量的变化，以及根除H. pylori前后胃活检组织中两种生物标志物——诱导型一氧化氮合酶（inducible nitric oxide synthase，iNOS）和细胞凋亡的变化。

方法

从人胃活检组织中分离的DNA经核酸酶P1消化成脱氧核苷酸，再经大肠杆菌碱性磷酸酶处理，然后用高效液相色谱-电化学检测系统（HPLC-ECD system）进行分析。8-OH-dG含量以每10⁵个脱氧鸟苷中的残基数量表示。用小鼠产生的抗人iNOS抗血清以1:500的稀释度进行iNOS免疫组织化学染色，并用原位末端脱氧核苷酸转移酶（TdT）介导的dUTP缺口末端标记法检测原位细胞凋亡。对H. pylori密度和炎症程度进行评分。

结果

幽门螺杆菌阴性的健康正常对照者的8-OH-dG含量为4.31±2.33（8-OH-dG/10⁵dG），而幽门螺杆菌阳性患者的8-OH-dG含量为10.40±7.25。这两个值之间的差异具有统计学意义（p<0.01）。根除H. pylori后，8-OH-dG含量显著降低（12.22±2.09对2.42±1.22，p<0.001）。根除H. pylori后，与根除前相比，细胞凋亡指数和iNOS评分均显著降低（细胞凋亡：3.72±1.74对1.17±1.06；iNOS：10.34±6.79对1.43±1.14，p<0.001）。在细胞凋亡指数、iNOS评分、炎症程度和H. pylori密度之间观察到具有统计学意义的相关性（p<0.05）。