【摘要】 目的利用牙周致病菌皮下感染和腹主动脉瘤复合动物模型探讨牙周致病菌影响小鼠腹主动脉瘤发展的可能分子机制。方法选择6～8周龄雄性C57BL/6小鼠,皮下金属螺旋管植入2周后,CaCl2涂抹法制备腹主动脉瘤模型,3周后在螺旋管内注射牙龈卟啉单胞菌(Pg)构建牙周致病菌感染模型,模型制备8周末处死取血和腹主动脉。腹主动脉行HE染色和弹力纤维染色进行病理分析。免疫组化染色观察MMP-9、S100A9在腹主动脉的表达。酶联免疫吸附法检测血循环中IL-6、MMP-9和S100A9的水平。结果 CaCl2处理8周末,Pg感染组小鼠的腹主动脉扩张率显著大于未感染组(P <0.01)。Pg感染组小鼠腹主动脉MMP-9(P <0.01)和S100A9(P <0.05)的表达显著高于未感染组。血循环中IL-6、MMP-9、S100A9水平较未感染组有升高趋势。结论牙龈卟啉单胞菌可能通过上调S100A9、MMP-9的表达来促进腹主动脉炎症,降解弹力纤维,导致动脉的扩张。更多还原

【Abstract】 Objective To investigate the plausible mechanism how Porphyromonas gingivalis（Pg） affects the progression of experimental abdominal aortic aneurysm（AAA） in a murine model. Methods AAA was produced in C57 BL/6 mice by the periaortic application of CaCl2 with NaCl as a control. The mice were inoculated once weekly with live Pg or vehicle. Eight weeks after the CaCl₂/NaCl application, the aortic tissues were harvested for immunohistochemistry and serum samples were taken for measuring the levels of IL-6, MMP-9 and S100 A9 by ELISA. Results Eight weeks after the periaortic application of either CaCl₂ or NaCl, a significant increase was observed in the aortic diameter in the CaCl₂ treatment groups, especially in the combined Pg-challenged mice. The tissue expressions of MMP-9（P <0.01） and S100 A9（P <0.05）elevated in mice with Pg challenge than those in mice with PBS. The circulating levels of MMP-9, S100 A9 and IL-6 also increased in Pg-challenged mice. Conclusions Pg may increase the expression of MMP-9 and S100 A9 in mice to promote inflammation of abdominal aorta and degrade elastic fiber, leading to the expansion of aorta.更多还原