Relationship between Hydroxy Fatty Acids and Prostaglandin E₂in Gingival Tissue

Abstract

Bacterial hydroxy fatty acids and alpha-hydroxy fatty acids have been demonstrated in complex lipid extracts of subgingival plaque and gingival tissue. However, little is known about the relationship between these hydroxy fatty acids in plaque and gingival tissues or the significance of these complex lipids in promoting inflammatory periodontal disease. The present study determined the percentages of ester-linked and amide-linked hydroxy fatty acids in complex lipids recovered from plaque and gingival tissue samples and the relationship between bacterial hydroxy fatty acids and alpha-hydroxy fatty acids in the lipid extracts. To evaluate a potential role for these hydroxy fatty acids in inflammatory periodontal disease, gingival tissue samples were examined for a relationship between prostaglandin E2 (PGE2) and hydroxy fatty acids recovered in gingival lipid. This investigation demonstrated that alpha-hydroxy fatty acids are only ester linked in plaque lipids but are largely amide linked in gingival tissue lipids. Furthermore, the level of alpha-hydroxy fatty acid in gingival lipid is directly related to the level of the bacterial hydroxy fatty acid 3-OHiso-branched C17:0 (3-OH iC17:0) in the same lipid extract. However, the relationship between hydroxy fatty acids in gingival lipids does not parallel the fatty acid relationship observed in plaque lipids. Finally, alpha-hydroxy fatty acid levels in gingival tissue lipids correlate directly with the recovery of PGE2 in the same tissue samples. These results demonstrate that alpha-hydroxy fatty acid levels in gingival lipids are directly related to both 3-OH iC17:0 bacterial lipid levels and PGE2 levels. These results indicate that in periodontal tissues there are unusual host-parasite interactions involving penetration of bacterial lipid in association with an altered gingival lipid metabolism and prostaglandin synthesis.

Porphyromonas gingivalis lipids and diseased dental tissues

“…A) Characteristic mass spectra for the two major phosphoethanolamine dihydroceramides of P. gingivalis . See (9) for the interpretation of the mass spectra and Fig. 2 for a description of other products that can produce the same mass spectra.…”

“…A previous report demonstrated elevated levels of 3‐OH iso C 17:0 in gingival tissue lipid extracts from periodontitis sites compared with healthy/mildly inflamed sites (6). A subsequent report indicated that the majority of 3‐OH iso C 17:0 in lipid extracts of gingival tissue is amide‐linked, suggesting contamination of diseased gingival tissues with bacterial ceramide lipids that contain 3‐OH iso C 17:0 (9). As these lipids could be important in the pathogenesis of destructive periodontal diseases, the purpose of this investigation was to determine whether the dihydroceramide lipids of P. gingivalis could be detected in lipid extracts of periodontally diseased teeth and gingival tissues.…”

Prostaglandin E2 secretion from gingival fibroblasts treated with interleukin‐1β: effects of lipid extracts from Porphyromonas gingivalis or calculus

“…This model therefore predicts that adult periodontitis is, in part, a lipid-mediated disease. Supporting this notion is the recently reported direct relationship between bacterial lipid penetration into gingival tissue and altered lipid metabolism within gingival tissue leading to elevated recovery of alpha hydroxy fatty acidcontaining complex lipids (6). While the signi®cance of altered lipid metabolism within gingival tissues is not clear, prostaglandin E 2 levels directly correlate with alpha hydroxy fatty acid-containing lipids in gingival tissue samples (6).…”

“…Regardless of the disease status of periodontal connective tissue, the predominant cell type recovered in gingival connective tissue is the ®broblast (5). Gingival ®broblasts are expected to be exposed to the previously mentioned bacterial lipids given the impressive recovery of bacterial lipids in diseased periodontal tissues (2,6). Furthermore, gingival ®broblasts are capable of secreting impressive levels of prostaglandin E 2 (7), a soluble host factor capable of proin¯ammatory eects with potentially adverse eects on bone and connective tissue homeostasis.…”

Prostaglandin E2 production and viability of cells cultured in contact with freshly mixed endodontic materials

“…Osteoblasts exposed to MTA produce elevated levels of interleukins-1 and -6 (Koh et al 1998). Both of these interleukins can cause the release of PGE 2 from fibroblasts (Richards & Rutherford 1988, Nichols & Maraj 1998, Lahiri et al 2001. Figure 1 Prostaglandin E 2 production (pg mL )1 ) by macrophages exposed to test materials.…”