Prostaglandin E(2) and tumour necrosis factor-alpha release by monocytes are modulated by phospholipids.
The regulation of pro- and anti-mediator release from cells within the alveolar space would represent a desirable mechanism serving to protect this delicate gas-exchanging region of the lung. This study investigates the effect of alveolar surfactant lipids on the regulation of tumour necrosis factor alpha (TNF-alpha), a potent inflammatory cytokine, and prostaglandin E(2)(PGE(2)), a lipid mediator with anti-inflammatory properties. The results of this investigation reveal a marked effect on the release of these two important mediators from a monocytic cell line, MonoMac 6 (MM6), by phosphatidylcholine (PC), phosphatidylethanolamine (PE), cholesterol (Chol) and sphingomyelin (SM). PC, PE and Chol demonstrated marked downregulation of TNF-alpha production at lipid concentrations of 125 and 250 microg/ml. Interestingly, SM significantly up regulated the release of TNF-alpha at these concentrations. However, the release of PGE(2)in MM6 cells incubated with the same lipids was significantly increased with PC and Chol, and significantly decreased in cells pre-treated with SM. This indicates a role for these lipids in alveolar immunoregulation.
Morris
R H
RH
School of Applied Sciences, University of Wales Institute, Cardiff, Wales, UK. kmorris@uwic.ac.uk
Price
A J
AJ
Tonks
A
A
Jackson
S K
SK
Jones
K P
KP
D002460:Cell Line; D002470:Cell Survival; D002784:Cholesterol / Q000494:pharmacology; D015232:Dinoprostone / Q000378:metabolism*; D015536:Down-Regulation; D006801:Humans; D007371:Interferon-gamma / Q000494:pharmacology; D050356:Lipid Metabolism; D008070:Lipopolysaccharides / Q000494:pharmacology; D009000:Monocytes / Q000378:metabolism*; D010713:Phosphatidylcholines / Q000494:pharmacology; D010714:Phosphatidylethanolamines / Q000494:pharmacology; D010743:Phospholipids / Q000378:metabolism*; D013109:Sphingomyelins / Q000494:pharmacology; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism*
D008070:Lipopolysaccharides; D010713:Phosphatidylcholines; D010714:Phosphatidylethanolamines; D010743:Phospholipids; D013109:Sphingomyelins; D014409:Tumor Necrosis Factor-alpha; D007371:Interferon-gamma; D002784:Cholesterol; D015232:Dinoprostone