青春期龈炎龈下菌斑中牙龈卟啉单胞菌的牙龈蛋白酶K的表达

Expression of gingipain K in Porphyromonas gingivalis in the subgingival plaque of puberty gingivitis

目的:检测并比较青春期龈炎的牙龈卟啉单胞菌(P.gingivalis)临床分离株的分泌蛋白和菌体蛋白中牙龈蛋白酶K(Kgp)的表达强度,揭示Kgp与青春期龈炎之间可能存在的致病关系。方法:受试对象为14～17岁青春期龈炎患者36例,检测并记录受检者的各牙周指数GI、SBI和PD测值,取龈下菌斑进行P.gin-givalis的分离培养,16SrRNAPCR法鉴定。将P.gingivalis临床分离株于对数生长期末提取分泌蛋白和菌体蛋白,用抗KgpN-末端IgG亚基的单克隆抗体进行Westernblot检测,采用SPSS11.0软件包,秩相关检验分析Kgp的表达强度与各牙周指数之间的相关关系。结果:青春期龈炎的P.gingivalis临床分离株的分泌蛋白和菌体蛋白中,KgpN-末端IgG亚基的表达强度与各牙周指数数值的高低有正相关关系,统计学上有显著性差异(P<0.01)。结论:Kgp对青春期龈炎有一定的致病作用。

Objective： To detect and compare the intensity of gingipain K （Kgp） in culture medium and cell extract of Porphyromonas gingivalis（ P. gingivalis） isolates in puberty gingivitis, and then to reveal the possible relationship between Kgp and puberty gingivitis. Methods： 36 patients with puberty gingivitis aged from 14 to 17 years were enrolled. Clinical parameters including GI, SBI and PD were evaluated before subgingival plaque samples collection. Subgingival plaque samples were collected and then P. gingivalis isolates were obtained. 16S rRNA PCR was used to confirm the presence of P. gingivalis in clinical isolates. Bacteria were cultured in BHI agar base and harvested at the end of log-phase growth. Culture fractions of P. gingivalis （culture medium and cell extracts） were performed with SDS-PAGE and Western blot technique using primary antibody against specific anti-Kgp N-terminal IgG subdomain. The data were statistically analyzed using SPSS 11.5 software. The relationship between the Kgp intensity and the clinical parameters was statistically analyzed using sum rank test. Results：There was positive correla- tion between the intensity of Kgp N-terminal IgG subdomain and the clinical parameters（ P 〈 0. 01 ）. Conclusion：In a certain degree, Kgp is contributed to the pathogenesis of puberty gingivitis, but the exact nosogenesis needs further studies.