A ceramide analog inhibits cPLA(2) activity and consequent PGE(2) formation in LPS-stimulated macrophages.
Prostaglandin E(2) (PGE(2)) is an important mediator of the inflammatory response. Phospho-ceramide analogue-1 (PCERA-1), a synthetic phospholipid-like molecule, was previously reported to modulate pro- and anti-inflammatory cytokine production. We show here that PCERA-1 inhibited LPS-stimulated PGE(2) production in RAW264.7 macrophages, without affecting COX-2 expression. Furthermore, PCERA-1 efficiently suppressed arachidonic acid (AA) release in response to LPS. The dephosphorylated derivative of PCERA-1, ceramide analogue-1 (CERA-1), mimicked the inhibitory effect of PCERA-1 on AA release and PGE(2) production in macrophages. Inhibition of PGE(2) production by CERA-1 was completely rescued by addition of exogenous AA. Importantly, PCERA-1 and ceramide-1-phosphate (C1P) stimulated the enzymatic activity of cPLA(2)α in an in vitro assay, whereas CERA-1 and ceramide inhibited both basal and C1P-stimulated cPLA(2)α activity. Collectively, these results indicate that CERA-1 suppresses AA release and subsequent PGE(2) production in LPS-stimulated macrophages by direct interaction with cPLA(2), and suggest that ceramide may similarly counteract C1P effect on cPLA(2) activity in cells. The suppression of PGE(2) production is suggested to contribute to the anti-inflammatory action of PCERA-1.
Department of Biochemistry and Molecular Biology, Life Sciences Institute, Tel-Aviv University, Tel-Aviv 69978, Israel.
Meir
M
Goldsmith
Ala
A
Daka
Nadia F
NF
Lamour
Roi
R
Mashiach
Yifat
Y
Glucksam
Michael M
MM
Meijler
Charles E
CE
Chalfant
Tsaffrir
T
Zor
D000818:Animals; D002460:Cell Line; D002518:Ceramides / Q000494:pharmacology*; D015232:Dinoprostone / Q000096:biosynthesis / Q000276:immunology*; D054513:Group IV Phospholipases A2 / Q000037:antagonists & inhibitors* / Q000276:immunology / Q000494:pharmacology; D008070:Lipopolysaccharides; D008264:Macrophages / Q000201:enzymology / Q000276:immunology*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C
D002518:Ceramides; D008070:Lipopolysaccharides; C541330:PCERA-1; D054513:Group IV Phospholipases A2; D015232:Dinoprostone