幽门螺杆菌jhp947基因对C57BL/6小鼠致病性研究

Pathogenicity of Hp jhp947 gene to C57BL/6 mice

检测jhp947对幽门螺杆菌(Helicobacter pylori,Hp)所致动物胃上皮细胞病变和基因表达的影响。【方法】将27只无特定病原体的(specified-pathogens free,SPF)6W龄C57BL/6小鼠随机分成3组,分别以J99、△J99-947(缺失jhp947基因)和PBS灌胃,菌量为109CFU/mL,0、2、4d各一次,4W后宰杀所有小鼠,无菌操作取胃组织,分别作快速尿素酶试验,Hp培养,组织病理学检查;免疫组化检测ESE-3A、NDRG1、MATP基因表达;半定量RT-PCR检测jhp947基因对小鼠ESE-3A、NADG1、MATP等基因转录的影响。【结果】J99组和△J99-947组快速尿素酶试验和Hp培养的阳性率均为100%,PBS对照组快速尿素酶试验和Hp培养阴性。组织病理学检查,PBS对照组小鼠胃黏膜100%正常,J99组小鼠胃黏膜33.3%(3/9)轻度糜烂,66.7%(6/9)重度糜烂。△J99-947组小鼠胃黏膜22.2%(2/9)正常,77.8%(7/9)轻度糜烂,没有重度糜烂。J99组小鼠胃黏膜的损伤比△J99-947组重。免疫组化检测结果,J99组比△J99-947组ESE-3A、NDRG1、MATP表达显著降低(P<0.05)。半定量RT-PCR检测结果,J99组比△J99-947组ESE-3A、NDRG1、MATP表达显著降低(P<0.05)。【结论】JHP947基因存在可使Hp感染所致的胃黏膜损伤程度加重。在体内jhp947基因可能通过下调NDRG1、MATP等肿瘤抑制基因的表达,这可能与胃癌的发生有关。

[ Objective] To study the effects of Helicobacter pylori jhp947 gene on the pathogenesis of epithelial cells and gene express pattern by animal studies. [Methods] Twenty-seven special pathogen free （SPF） C57BL/6 mice were divided equally into3 groups, and challenged with Helicobacter pylori J99, Helicobacter pylori △J99-947 and phosphate buffer （PBS） respectively,at a dose of 109 colony lorraine unit （CFU） at 0, 2, and 4 days. Mice were sacrificed 4 weeks after the last challenge, and went through rapid urease test, culture of Hp, histological examination, immunofluorescent histochemistry and semiquantitative reverse transcription PCR （RT-PCR） of gastric mucosa. [Results] The result of rapid urease test and culture of Hp indicated that the positive rates in J99 and △J99-947 group were both 100% while 0% in PBS group. The result of histology examination indicated that garstirc mucosa is all normal in PBS group; in J99 group, 33.3% （3/9） had slightly anabrosis, 66.7% （6/9） had seriously anabrosis; in △J99-947 group,22.2% （2/9） is normal,77.8% （7/9） had slightly anabrosis. The degree of anabrosis seems to be more severe in J99 than in △J99-947. The result of immunofluorescent histochemistry and semiquantitative RT-PCR of gastric mucosa indicated that the expression level of ets homologous factor, N-myc downstream regulated gene 1, methylthioadenosine phosphorylase is significantly lower in J99 than in ,△J99-947 group （P 〈 0.05）. [ Conclusion] The degree of anabrosis seems to be more severe in Hp with jhp947 gene than in Hp without jhp947 gene. In vivo, jhp947 may induce tumorigenesis by inhibiting anti-oncogenes （N-myc downstream regulated gene 1 and methylthioadenosine phosphorylase）.