101. Arginine-specific gingipain A from Porphyromonas gingivalis induces Weibel-Palade body exocytosis and enhanced activation of vascular endothelial cells through protease-activated receptors
- Author
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Megumi Inomata, Kenji Matsushita, Takeshi Into, Yuichi Ishihara, Misako Nakashima, and Toshihide Noguchi
- Subjects
Umbilical Veins ,Receptors, Proteinase-Activated ,Immunology ,Microbiology ,Exocytosis ,Proinflammatory cytokine ,Angiopoietin ,Weibel–Palade body ,Humans ,Adhesins, Bacterial ,Porphyromonas gingivalis ,Cells, Cultured ,Weibel-Palade Bodies ,biology ,Endothelial Cells ,biology.organism_classification ,Cell biology ,Gingipain ,Endothelial stem cell ,Cysteine Endopeptidases ,Infectious Diseases ,Gingipain Cysteine Endopeptidases ,Endothelium, Vascular ,Cell activation - Abstract
Gingipains, cysteine proteases derived from Porphyromonas gingivalis, are important virulence factors in periodontal diseases. We found that arginine-specific gingipain A (RgpA) increased the responsiveness of vascular endothelial cells to P. gingivalis lipopolysaccharides (LPS) and P. gingivalis whole cells to induce enhanced IL-8 production through protease-activated receptors (PARs) and phospholipase C (PLC) gamma. We therefore investigated whether RgpA-induced enhanced cell activation is mediated through exocytosis of Weibel-Palade bodies (WPBs) because they store vasoactive substances. RgpA rapidly activated PAR- and PLCgamma-dependent WPB exocytosis. In addition, angiopoietin (Ang)-2, a substance of WPB, enhanced IL-8 production by P. gingivalis LPS, suggesting that Ang-2 mediates the RgpA-induced enhanced cell responses. Thus, we propose a novel role for RgpA in induction of a proinflammatory event through PAR-mediated WPB exocytosis, which may be an important step for enhanced endothelial responses to P. gingivalis.
- Published
- 2007
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