Abstract: Objective To use the Porphyromonas gingivalis ipopolysaccharide(P.gingivalis-LPS) to infect human u-mbilical vein endothelial cells (HUVECs), then to observe the change of matrix metalloproteinase-9(MMP-9) in infected endothelial and to discuss the relationship between P.gingivalis and atherosclerosis (atherosclerosis,AS) at the same time. Methods First HUVECs were cultured in vitro, and different concentrations of P.gingivalis-LPS were put into the cultivated cell solution after fusion to monolayers. Then enzyme linked immunosorbent assay (enzyme linked immunosorbent assay, ELISA) was technically used for detecting the expression of MMP-9 in HUVECs as co-cultured for 6,18,24 hours respectively. The influence of P.gingivalis-LPS on HUVECs proliferation was detected by MTT assay. Results Under the environments of our experiment, the expression levels of MMP-9 increased (P<0.05) after the stimulation on HUVECs with different concentrations of P.gingivalis-LPS for 6,18, 24 hours. Compared with control group, after the treatment of P.gingivalis-LPS, HUVECs showed obviously decreased proliferation viability(P<0.01). Conclusion P.gingivalis-LPS can increase the expression level of MMP-9 in HUVECs, and then accelerate the occurrence and development of AS.

Key words: P.gingivalis-LPS, human umbilical vein endothelial cell, MMP9, atherosclerosis