脂磷壁酸诱导根尖骨吸收调控蛋白的表达

Expression of periapical bone resorption-regulating proteins induced by lipoteichoic acid

目的研究难治性根尖周炎重要病原菌粪肠球菌脂磷壁酸对骨吸收核心调控系统,核因子κB受体活化因子配体(RANKL)和骨保护素(OPG)蛋白表达的影响。方法采用甲基噻唑基四唑(MTT)法检测0.1、1.0、10.0、20.0mg/L脂磷壁酸作用24、48、72h后对人牙周膜成纤维细胞(HPDLFs)增殖的影响。细胞免疫荧光和蛋白免疫印迹法检测脂磷壁酸刺激HPDLFs 24h后RANKL、OPG表达水平及RANKL/OPG值的变化。结果脂磷壁酸抑制HPDLFs增殖具有浓度和时间依赖性。10.0mg/L脂磷壁酸刺激24h后,HPDLFs中RANKL、OPG蛋白表达均增加,RANKL的增长速度较OPG快,脂磷壁酸上调RANKL/OPG值具有浓度依赖性,高浓度组明显大于对照组(P<0.05)。结论脂磷壁酸对牙周膜成纤维细胞增殖具有抑制作用,可上调细胞RANKL、OPG表达及RANKL/OPG值,推测其在难治性根尖周炎骨吸收中扮演重要作用。

Objective To explore the effect of the pathogenic bacteria of refractory periapical periodontitis, Enterococcus faecalis lipoteichoie acid on bone resorption, and to investigate the protein expression of receptor activator of nuclear factor-κB ligand （RANKL） as well as osteoprotegerin （OPG） in HPDLFs stimulated by lipoteichoic acid. Methods MTT chromatometry was used to determine HPDLFs activity after stimulated by 0.1, 1.0, 10.0 and 20.0 mg/L lipoteichoic acid for 24, 48 and 72 h. In addition, HPDLFs were collected after stimulation with lipoteichoic acid for 24 h. The protein expression of RANKL and OPG in HPDLFs were then evaluated by cell immunofluorescence and western blotting. Results Lipoteichoic acid inhibited HPDLFs viability in a dose-and-time-dependent fashion. RANKL and OPG protein level were both significantly up-regulated after stimulation with 10.0 mg/L Lipoteichoic acid for 24 h. The growth rate of RANKL was faster than OPG. Therefore, the ratio of RANKL/OPG was up-regulated by lipoteichoic acid in a dose-dependent fashion. The gray values and the ratio of the lipoteichoic acid high concentration group were statistically higher than those of the control group （P〈0.05）. Conclusions Lipoteiehoie acid could inhibit HPDLFs proliferation, and up- regulate both the protein expression and the ratio of RANKL/OPG. This indicated that lipoteichoic acid might play a crucial role in refractory periapical periodontitis.