Hamanaka Y, Nakashima M, Wada A, Ito M, Kurazono H, Hojo H, Nakahara Y, Kohno S, Hirayama T, Sekine I
Department of Molecular Pathology, Nagasaki University School of Medicine, Nagasaki, Japan.
Gut. 2001 Oct;49(4):481-7. doi: 10.1136/gut.49.4.481.
Human beta-defensin 2 (hBD-2) plays a role in the innate defence system at mucosal surfaces. Colonisation of Helicobacter pylori in the stomach is an important pathological factor in gastrointestinal illnesses, including gastritis, peptic ulcer, and gastric adenocarcinoma.
To evaluate the antibacterial role of hBD-2 against H pylori infection in the gastric mucosa.
Biopsied gastric mucosa specimens from H pylori positive (n=6) and H pylori negative (n=6) individuals were used. H pylori was determined by the presence of urease activity and microscopic examination.
The specimens were examined for hBD-2 expression by reverse transcription-polymerase chain reaction (RT-PCR), immunohistochemistry, and in situ hybridisation. The antibacterial effect of hBD-2 against H pylori was evaluated by the number of colony forming units of H pylori after incubation with 0, 10(-9), 10(-8), 10(-7), 10(-6), or 10(-5) M of hBD-2 peptide.
All six H pylori positive specimens expressed a high level of hBD-2 mRNA while hBD-2 mRNA was not detected in the H pylori negative specimens by RT-PCR. Immunohistochemistry using anti-hBD-2 antiserum revealed that hBD-2 was expressed in the surface epithelium of H pylori infected specimens. In gastric specimens obtained after H pylori eradication, hBD-2 immunoreactivity had dramatically decreased. In situ hybridisation confirmed that hBD-2 transcripts were localised in the epithelium of H pylori infected gastric specimens. Incubation with hBD-2 reduced the growth rate of cultured H pylori in a dose dependent manner, and incubation with 10(-5) M hBD-2 completely inhibited the proliferation of H pylori.
H pylori infection induces hBD-2 expression in the human gastric epithelium. hBD-2 inhibited the growth of H pylori in vitro, suggesting that hBD-2 plays an antibacterial role in H pylori induced gastritis.
人β-防御素2（hBD-2）在黏膜表面的固有防御系统中发挥作用。幽门螺杆菌在胃内定植是包括胃炎、消化性溃疡和胃腺癌在内的胃肠道疾病的重要病理因素。
评估hBD-2对胃黏膜幽门螺杆菌感染的抗菌作用。
使用来自幽门螺杆菌阳性（n = 6）和幽门螺杆菌阴性（n = 6）个体的胃黏膜活检标本。通过尿素酶活性和显微镜检查确定幽门螺杆菌。
通过逆转录-聚合酶链反应（RT-PCR）、免疫组织化学和原位杂交检测标本中hBD-2的表达。通过在0、10⁻⁹、10⁻⁸、10⁻⁷、10⁻⁶或10⁻⁵M的hBD-2肽孵育后幽门螺杆菌的菌落形成单位数量评估hBD-2对幽门螺杆菌的抗菌作用。
所有6份幽门螺杆菌阳性标本均表达高水平的hBD-2 mRNA，而通过RT-PCR在幽门螺杆菌阴性标本中未检测到hBD-2 mRNA。使用抗hBD-2抗血清的免疫组织化学显示hBD-2在幽门螺杆菌感染标本的表面上皮中表达。在根除幽门螺杆菌后获得的胃标本中，hBD-2免疫反应性显著降低。原位杂交证实hBD-2转录本定位于幽门螺杆菌感染的胃标本的上皮中。与hBD-2孵育以剂量依赖方式降低了培养的幽门螺杆菌的生长速率，并且与10⁻⁵M hBD-2孵育完全抑制了幽门螺杆菌的增殖。
幽门螺杆菌感染诱导人胃上皮中hBD-2的表达。hBD-2在体外抑制幽门螺杆菌的生长，表明hBD-2在幽门螺杆菌诱导的胃炎中发挥抗菌作用。
