Structures and biological activities of novel phosphatidylethanolamine lipids of Porphyromonas gingivalis.
The Gram-negative periodontal pathogen Porphyromonas gingivalis synthesizes several classes of novel phosphorylated complex lipids, including the recently characterized phosphorylated dihydroceramides. These sphingolipids promote the interleukin-1 (IL-1)-mediated secretion of inflammatory mediators from fibroblasts, including prostaglandin E2 and 6-keto prostaglandin F2alpha, and alter gingival fibroblast morphology in culture. This report demonstrates that one additional class of phosphorylated complex lipids of P. gingivalis promotes IL-1-mediated secretory responses and morphological changes in cultured fibroblasts. Structural characterization identified the new phospholipid class as 1,2-diacyl phosphatidylethanolamine, which substituted predominantly with isobranched C15:0 and C13:0 fatty acids. The isobranched fatty acids, rather than unbranched fatty acids, and the phosphoethanolamine head group were identified as the essential structural elements required for the promotion of IL-1-mediated secretory responses. These structural components are also observed in specific phosphorylated sphingolipids of P. gingivalis and likely contribute to the biological activity of these substances, in addition to the phosphatidylethanolamine lipids described in this report.
Nichols
Frank C
FC
Department of Periodontology, University of Connecticut School of Dental Medicine, Farmington, CT 06030, USA. nichols@nso.uchc.edu
Riep
Birgit
B
Mun
Jiyoung
J
Morton
Martha D
MD
Kawai
Toshihisa
T
Dewhirst
Floyd E
FE
Smith
Michael B
MB
D015121:6-Ketoprostaglandin F1 alpha / Q000032:analysis; D002478:Cells, Cultured; D003470:Culture Media / Q000737:chemistry; D015237:Dinoprost / Q000032:analysis; D015232:Dinoprostone / Q000032:analysis; D005227:Fatty Acids / Q000737:chemistry / Q000378:metabolism; D005347:Fibroblasts / Q000166:cytology / Q000378:metabolism; D005881:Gingiva / Q000166:cytology; D007375:Interleukin-1 / Q000378:metabolism; D015394:Molecular Structure; D010714:Phosphatidylethanolamines / Q000737:chemistry / Q000378:metabolism; D016966:Porphyromonas gingivalis / Q000737:chemistry* / Q000378:metabolism; D021241:Spectrometry, Mass, Electrospray Ionization
D003470:Culture Media; D005227:Fatty Acids; D007375:Interleukin-1; D010714:Phosphatidylethanolamines; D015121:6-Ketoprostaglandin F1 alpha; D015237:Dinoprost; D015232:Dinoprostone