Porphyromonas gingivalis Lipopolysaccharide Regulates Migration of Vascular Smooth Muscle Cells

ABSTRACT

Porphyromonas gingivalis, a foremost periodontal pathogen, has been known to cause periodontal diseases. Epidemiologic evidences have indicated the involvement of P. gingivalis in the development of cardiovascular diseases. In this study, we show that the P. gingivalis lipopolysaccharide increases the mRNA expression and protein secretion of interleukin-6 in vascular smooth muscle cells. We demonstrate that P. gingivalis LPS activates the extracellular signal-regulated kinase 1/2 (ERK1/2), p38 mitogen-activated protein kinase (MAPK), and Akt, which mediate the IL-6 expression in vascular smooth muscle cells. Also, P. gingivalis LPS stimulates the vascular smooth muscle cell migration, which is a critical step for the progression of atherosclerosis. Moreover, neutralization of the IL-6 function inhibits the migration of vascular smooth muscle cells induced by P. gingivalis LPS. Taken together, these results indicate that P. gingivalis LPS promotes the expression of IL-6, which in turn increases the migration of vascular smooth muscle cells.