Abstract: Objective： Growth-arrest-specific protein 6 （Gas6）is a vitamin K-dependent protein and involved in cell proliferation, survival, adhesion and migration . Also it has been shown to play an important role in the inflammatory response .The aim of present study was to investigate the role of Gas6 in the process of the expression of adhesion molecules and chemokines of human umbilical vein endothelial cells（HUVECs）induced by Porphyromonas gingivalis lipopolysaccharide（P.g-LPS）. Methods： After up-regulation and down-regulation of the expression of Gas6，the vascular endothelial cells were stimulated with 1 mg/L P.gLPS for 3 h and 24 h. Realtime quantitative polymerase chain reaction（realtime PCR）was taken to detect the expression of the cell adhesion molecules：intercellular adhesion molecule-1（ICAM-1） and E-selectin, as well as chemokines：interleukin-8（IL-8）and monocyte chemoattractant protein 1（MCP-1）. Wound healing assay was taken to observe the migration ability of endothelium cells in different groups. Results： After 3 h of P.g- LPS stimulation, the expression of adhesion molecules and chemokine in the down-regulation group was not significantly different from that in the control group，while in the up-regulation group the decrease of E-selectin, ICAM-1, IL-8 and MCP-1 was 81%±0%, 47%±3%, 76% ± 3%, 26% ± 6% respectively. After 24 h of P.g- LPS stimulation, the expression of adhesion molecules and chemokine in down-regulation group was significantly higher than that in control group (2.06±0.07, 1.99±0.11, 3.14±0.15, 1.84±0.03 flod), while these molecules in the down-regulation group was significantly lower than in the control group (29%±1%, 62%±3%, 69%±1%, 41%±2%）. Differences were statistically significant （P<0.01）. Wounding healing assay showed that down-regulation of Gas6 enhanced migration ability of endothelial cells while up-regulation of Gas6 weakened this ability，which was consistent with the trend of real-time PCR result. Conclusion： Down-regulation of the Gas6 gene enhanced the expression of ICAM-1, E-selectin, IL-8 and MCP-1 in HUVECs after P.g-LPS stimulating， while up-regulaiton of the Gas6 gene weakened the expression of ICAM-1, E-selectin, IL-8 and MCP-1 in HUVECs after P.g- LPS stimulating，suggesting that Gas6 may play a role in the process of endothelial cell adhesion.

Key words: Human umbilical vein endothelial cells, Growth-arrest-specific protein 6, Porphyromonas gingivalis lipopolysaccharide, Biological factors