Abstract: Objective To explore the effect of porphyromonas gingivalis lipopolysaccharides (P.gLPS) on the expression of CD36 and LOX1 macrophages derived from THP1.Methods THP1 cells were cultured in the presence of 160 nmol/L phorbol 12myristate 13acetate (PMA) for 48 h.An cocultured in vitro model of P.gLPS and THP1 macrophage cells was constructed.In the presence of LDL (50 μg/ml),macrophage cells were incubated with P.gLPS (0.1,1,10 μg /ml) for 48 h or with 1μg/ml P.gLPS for 24,48,72h.The expression of CD36,LOX1 at mRNA and protein levels was determined by real time PCR and Western blot.Results THP1 cells were differentiated into macrophages after the addition of PMA for 48h.P.gLPS downregulated the mRNA and protein expression of CD36 as concentration increased and time extended in the presence of LDL (P<0.05).However,P.gLPS had no effect on the expression of LOX1 at mRNA and protein levels compared with control group.Conclusions P.gLPS downregulated CD36,but had no effect on the expression of LOX1,which may contribute to the excessive accumulation of cholesteryl esters and conversion to foam cells in macrophages.

Key words: Porphyromonas gingivalis, lipopolysaccharide, THP-1 monocytes, CD36, LOX-1