Purpose: To investigate the effect of lipopolysaccharides(LPS) extracted from Porphyromonas endodontalis(P.e) on the expression of macrophage inflammatory protein-2 (MIP-2) mRNA and protein levels in MC3T3-E1 cells and the influence of resveratrol on the expression of MIP-2 protein in P.e-LPS induced cells.
Methods: MC3T3-E1 cells were treated with different concentrations of P.e-LPS(0-50 mg/L) and 20 mg/L P.e-LPS for different time (0-48 h). The expression of MIP-2 mRNA and protein was detected by real-time RT-PCR and enzyme linked immunosorbent assay (ELISA). MC3T3-E1 cells were pretreated with resveratrol for 1 h in the presence of 20 mg/L P.e-LPS for 24 h，which was detected by ELISA. Statistical analysis was performed using one-way ANOVA and Dunnett t test with SPSS 13.0 software package.
Results: Treatment of MC3T3-El cells with different concentrations of P.e-LPS(0-50 mg/L) caused a significantly increase in MIP-2 mRNA and protein expression in dose-dependent manners.The expression of MIP-2 protein increased from (41.86±2.49) ng/L to (3126.74±158.30) ng/L, and the difference was significant(P<0.05). In the observation time (0-48 h), the impact of 20 mg/L P.e-LPS on induction of MIP-2 in MC3T3-El cells exhibited a time-dependent manner. At 48 h, the maximal induction of MIP-2 protein expression was (2102.55±123.27) ng/L(P<0.01). Incubation of cells with 10 μmol/L resveratrol for 1h significantly decreased the expression of MIP-2 protein from (1805.33±67.54) ng/L to（813.82±47.21) ng/L, and the difference was significant(P<0.05).
Conclusions: The results suggest that P.e-LPS may mediate MIP-2 expression in MC3T3-E1 cells, and resveratrol has a significant inhibitory effect on this process.