Fimbria-dependent activation of pro-inflammatory molecules in Porphyromonas gingivalis infected human aortic endothelial cells

Abstract

SummaryEpidemiological studies support that chronic periodontal infections are associated with an increased risk of cardiovascular disease. Previously, we reported that the periodontal pathogen Porphyromonas gingivalis accelerated atherosclerotic plaque formation in hyperlipidemic apoE -/-mice, while an isogenic fimbria-deficient (FimA-) mutant did not. In this study, we utilized 41 kDa (major) and 67 kDa (minor) fimbria mutants to demonstrate that major fimbria are required for efficient P. gingivalis invasion of human aortic endothelial cells (HAEC). Enzymelinked immunosorbent assay (ELISA) revealed that only invasive P. gingivalis strains induced HAEC production of pro-inflammatory molecules interleukin (IL)-1 β β β β , IL-8, monocyte chemoattractant protein (MCP)-1, intracellular adhesion molecule (ICAM)-1, vascular cellular adhesion molecule (VCAM)-1 and Eselectin. The purified native forms of major and minor fimbria induced chemokine and adhesion molecule expression similar to invasive P. gingivalis , but failed to elicit IL-1 β β β β production. In addition, the major and minor fimbria-mediated production of MCP-1 and IL-8 was inhibited in a dose-dependent manner by P. gingivalis lipopolysaccharide (LPS). Both P. gingivalis LPS and heat-killed organisms failed to stimulate HAEC. Treatment of endothelial cells with cytochalasin D abolished the observed pro-inflammatory MCP-1 and IL-8 response to invasive P. gingivalis and both purified fimbria, but did not affect P. gingivalis induction of IL-1 β β β β . These results suggest that major and minor fimbria elicit chemokine production in HAEC through actin cytoskeletal rearrangements; however, induction of IL-1 β β β β appears to occur via a separate mechanism. Collectively, these data support that invasive P. gingivalis and fimbria stimulate endothelial cell activation, a necessary initial event in the development of atherogenesis.

Defining the gut microbiota in individuals with periodontal diseases: an exploratory study

“…Oral bacteria can enter the circulation and cause bacteraemia by actively crossing the periodontal epithelium [18–20], or by being inoculated through mechanical procedures, including periodontal debridement, flossing and brushing [21,22]. Periodontal pathogens, such as Aggregatibacter actinomycetemcomitans, Treponema denticola and Porphyromonas gingivalis are also capable of invading endothelial cells [23–27], and they have been detected in atherosclerotic plaques, heart valves, aortic aneurysms, carotid and coronary vessels [28–33]. Studies in a variety of animal models have demonstrated that recurrent bacteraemia or oral administration with P. gingivalis can enhance atherogenesis [34,35].…”

Bacterial Fimbriae Stimulate Proinflammatory Activation in the Endothelium through Distinct TLRs

“…Erythromycin (1.0 g/ml) and tetracycline (2.0 g/ml) were added according to the selection requirements of the strains (30). Fimbriae were prepared according to a modification of the method described by Arai et al (31).…”

“…Using major and minor fimbriae mutants we demonstrated that major fimbriae are required for P. gingivalis invasion of HAEC and that only invasive P. gingivalis strains induced the production of proinflammatory molecules IL-1␤, IL-8, MCP-1, ICAM-1, VCAM-1, and E-selectin (30). Our work demonstrated that following major fimbriae-mediated initial attachment, the minor fimbriae play an important role in more intimate attachment facilitating endocytosis of the bacteria (30). The purified native forms of the major and minor fimbriae induced chemokine and adhesion molecule expression similar to invasive P. gingivalis, but failed to elicit IL-1␤ production.…”

Study of Hgp44 from Porphyromonas gingivalis on inducing HUVECs to secrete IL-6 and IL-8

“…Increased levels of IL-6 and IL-8 correlate with prognosis in patients with the risk of coronary heart disease (Hartford et al, 2006). Furthermore, several in vitro experiments have shown that bacterial products of P. gingivalis, such as fimbriae, LPS and gingipains, promote IL-6 and IL-8 production in gingival fibroblasts and epithelial cells (Matsushita et al, 2006;Takahashi et al, 2006;Roth et al, 2007).…”