Biologic Activity of Porphyromonas endodontalis Complex Lipids

Abstract

Introduction Periapical infections secondary to pulpal necrosis are associated with bacterial contamination of the pulp. Porphyromonas endodontalis, a Gram-negative organism, is considered to be a pulpal pathogen. P. gingivalis is phylogenetically related to P. endodontalis and synthesizes several classes of novel complex lipids that possess biological activity, including the capacity to promote osteoclastogenesis and osteoclast activation. The purpose of this study was to extract and characterize constituent lipids of P. endodontalis, and evaluate their capacity to promote pro-inflammatory secretory responses in the macrophage cell line, RAW 264.7, as well as their capacity to promote osteoclastogenesis and inhibit osteoblast activity. Methods Constituent lipids of both organisms were fractionated by HPLC and were structurally characterized using electrospray-mass spectrometry (ESI-MS) or ESI-MS/MS. The virulence potential of P. endodontalis lipids was then compared with known biologically active lipids isolated from P. gingivalis. Results P. endodontalis total lipids were shown to promote TNF-α secretion from RAW 264.7 cells and the serine lipid fraction appeared to account for the majority of this effect. P. endodontalis lipid preparations also increased osteoclast formation from RAW 264.7 cells but osteoblast differentiation in culture was inhibited and appeared to be dependent on TLR2 expression. Conclusions These effects underscore the importance of P. endodontalis lipids in promoting inflammatory and bone cell activation processes that could lead to periapical pathology.

Porphyromonas endodontalis reactivates latent Epstein–Barr virus

“…The colonization of P. endodontalis causes periapical lesions with acute symptoms, such as pain and swelling in response to purulent inflammation (Mirucki et al . ). Additionally, P. endodontalis induces inflammatory cytokines by stimulation with its lipopolysaccharide (Murakami et al .…”

“…Porphyromonas endodontalis is a black-pigmented Gram-negative anaerobe associated with endodontic infections and pulp necrosis (Gomes et al 2008). The colonization of P. endodontalis causes periapical lesions with acute symptoms, such as pain and swelling in response to purulent inflammation (Mirucki et al 2014). Additionally, P. endodontalis induces inflammatory cytokines by stimulation with its lipopolysaccharide (Murakami et al 2001), and subsequent bone resorption can occur (Tang et al 2011).…”

Are Sphingolipids and Serine Dipeptide Lipids Underestimated Virulence Factors of Porphyromonas gingivalis?

“…Recently, it was suggested that commensal Bacteroidetes, to which P. gingivalis belongs, that reside in the oral cavity and gut contribute to the pathogenesis of TLR2-dependent atherosclerosis through deposition and metabolism of serine dipeptide lipids in artery walls (6). In addition to P. gingivalis, the common dental pulpal pathogen Porphyromonas endodontalis produces the lipid 654 class (36). The lipid 654 preparations isolated from both Porphyromonas species were shown to promote osteoclast formation from RAW 264.7 cells (36), indicating that in addition to sub PG DHC lipids, osteoclast activation is promoted by serine dipeptide lipids and that the bacterial source of lipid 654 is probably not a critical issue.…”

“…In addition to P. gingivalis, the common dental pulpal pathogen Porphyromonas endodontalis produces the lipid 654 class (36). The lipid 654 preparations isolated from both Porphyromonas species were shown to promote osteoclast formation from RAW 264.7 cells (36), indicating that in addition to sub PG DHC lipids, osteoclast activation is promoted by serine dipeptide lipids and that the bacterial source of lipid 654 is probably not a critical issue.…”

PS, It’s Complicated: The Roles of Phosphatidylserine and Phosphatidylethanolamine in the Pathogenesis of Candida albicans and Other Microbial Pathogens

“…Lipids are one of the four main macromolecules (along with nucleic acids, proteins and carbohydrates) essential for cells to function. Depending on their properties, lipids can have many roles in the cell including control of membrane structure and fluidity [ 4 , 5 ], signaling [ 6 ], facilitating membrane-associated functions [ 4 , 7 ], virulence [ 8 , 9 , 10 , 11 , 12 ] and drug resistance [ 4 , 13 , 14 ]. A great deal of research has been conducted to help better understand the role that lipids play in virulence across species and even within strains of the same species [ 15 , 16 , 17 ].…”