牙龈卟啉单胞菌脂多糖对成骨细胞EphA2表达的调控

目的：研究小鼠前成骨细胞系MC3T3-E1在成骨分化过程中,牙龈卟啉单胞菌脂多糖（Pg-LPS）对EphA2表达的影响。方法：使用终浓度1mg/L的Pg-LPS与MC3T3-E1共培养,分别在第3、7、14天3个时间点,采用RT-PCR和Western-Blot技术测定EphA2的表达和成骨相关基因的表达,并通过PNPP法测定碱性磷酸酶活性。结果：RT-PCR结果提示,在第3天和第7天,实验组比对照组EphA2基因表达分别增高4.5倍和1.3倍,两组之间存在显著差异（P〈0.05）。同时成骨标志物ALP和Sp7基因表达降低,与对照组相比差异有显著性,但Runx2和ColⅠ基因的表达则无明显差异。但是在第14天,实验组和对照组之间EphA2和成骨相关基因表达均无显著性差异。Western-Blot结果提示,在第7天实验组比对照组EphA2蛋白表达增加。结论：Pg-LPS对前成骨细胞系MC3T3-E1细胞,在成骨分化的早期和中期能够促进EphA2的表达,但是在成骨分化晚期对EphA2的表达则无明显作用。

Effect of Porphyromonas Gingivalis Lipopolysaccharide on the Expression of EphA2 in MC3T3-E1 Cell

Objective：To investigate the effect of porphyromonas gingivalis lipopolysaccharide（Pg-LPS）on the expression of EphA2in MC3T3-E1cells during osteoblastic differentiation.Methods：MC3T3-E1cells were cocultured with 1mg/L of Pg-LPS at 3,7and 14d.EphA2and the osteogenic related genes（Runx2,ColⅠ,ALP and Sp7）were detected by RT-PCR and Western-Blot.The alkaline phosphatase activity was determined by PNPP method.Results：RT-PCR demonstrated that compared with the control group,at the 3dand 7d,the EphA2mRNA expression was significantly increased 4.5-fold and 1.3-fold in Pg-LPS group.Meanwhile PgLPS stimulation significantly inhibited osteogenic related genes of ALP and Sp7expressions,but the gene expressions of ColⅠand Runx2had no significant difference.At the 14d,there was no obvious difference between the Pg-LPS group than control group.Western-blot demonstrated that at 7d,the EphA2protein expression was significantly increased.Conclusion：Pg-LPS can promote the expression of EphA2in the early and middle stage of osteoblast differentiation,but has no obvious effect in the late stage.