[P3-3-23] Effects of Streptococcus sanguinis membrane vesicles on induction of inflammation in endothelial cells
Keywords:Streptococcus sanguinis、膜小胞、HUVEC
Our previous study reported that Streptococcus sanguinis, one of oral commensal bacteria, caused inflammation in blood vessels, leading to progression of formation of atherosclerotic plaques. Furthermore, inflammatory responses were induced in human umbilical vein endothelial cells (HUVEC) by stimulation with S. sanguinis. On the other hand, it is known that membrane vesicles (MV) secreted from bacteria have various roles in cell-cell interactions. The MV contains various virulent factors. However, the role of S. sanguinis MV is not known. Thus, in this study, we assessed the effect of MV secreted from S. sanguinis on HUVEC. We purified S. sanguinis MV from culture supernatant of S. sanguinis cultures by ultracentrifugation. Various amounts of purified MV or S. sanguinis cells were added to the culture of HUVEC, and expressions of inflammatory related factors were assessed using real-time PCR and ELISA. Our results showed that the expressions of TLR2 and ICAM-1 mRNA were upregulated in HUVEC by stimulation with S. sanguinis MVs or S. sanguinis cells. Monocyte chemotaxis protein-1 production was also increased in S. sanguinis MV-treated HUVEC. These results suggested that both S. sanguinis and S. sanguinis MV may be recognized by receptors expressed in HUVEC, which resulted in induction of inflammation in endothelial cells.