OBJECTIVETo investigate the effects of Porphyromonas gingivalis lipopolysacchearide (Pg-LPS) on the expression of CC chemokine receptor 2 (CCR2) in THP-1 monocyte and to explore the relationship between periodontitis and cardiovascular disease in molecular level.

METHODSTHP-1 monocytes were incubated with different concentrations of Pg-LPS (10, 100, 1000 µg/L) for 1, 4 and 24 h respectively, then flow cytometry and reverse transcription-PCR were adopted to determine cell surface protein levels and mRNA levels of CCR2.

RESULTSThe protein levels and mRNA levels of CCR2 were higher in all experiment groups of 1 h and 4 h than that in the control group (P < 0.05) , except the protein expression of CCR2 in T1 group of 1 h (55.74 ± 0.96) . The protein expression (52.56 ± 0.61, 40.98 ± 0.86, 26.50 ± 0.67) and mRNA levels (0.095 ± 0.006,0.070 ± 0.004,0.046 ± 0.004) of CCR2 were lower in all experiment groups than that in the control group (56.99 ± 0.44,0.104 ± 0.003) at 24 h (P < 0.05) . The protein levels and mRNA levels of CCR2 were increased in all experiment groups at 4 h and reduced at 24 h (P < 0.05).

CONCLUSIONSPg-LPS can upregulate CCR2 expression on THP-1 monocyte surface in concentration dependent manner in early stage, promoting the monocyte chemoattractant. Periodontitis may promote atherosclerosis by enhancing monocyte chemoattractant through periodontal pathogens.