Prostaglandin H-synthase-2 is the main enzyme involved in the biosynthesis of octadecanoids from linoleic acid in human dermal fibroblasts stimulated with interleukin-1beta.
This study was focused on the characterization of the metabolism of linoleic acid by human dermal fibroblasts and the effect of interleukin-1 on the biosynthesis of octadecanoids. Dermal fibroblasts untreated and treated with recombinant IL-1beta were incubated with exogenous labeled linoleic acid. A combination of high performance liquid chromatography and gas chromatography-mass spectrometry was used as the analytic technique. We found that dermal fibroblasts convert linoleic acid mainly into 13-hydroxy-9-cis,11-trans-octadecadienoic acid (13-HODE) and 9-hydroxy-10-trans,12-cis-octadecadienoic acid (9-HODE), 13(S)-HODE and 9(R)-HODE being the predominant enantiomers. IL-1beta increased the formation of both 13-HODE and 9-HODE in a concentration-dependent manner with similar EC50 values as for prostanoid formation. This effect of IL-1beta on HODEs formation was concomitant with the expression of prostaglandin H-synthase-2. Formation of octadecanoids was inhibited in a concentration-dependent manner by acetylsalicylic acid and indomethacin. Dexamethasone, actinomycin D, and cycloheximide abolished the effect of IL-1beta on HODEs biosynthesis. Octadecanoid biosynthetic activity was associated with the microsomal fraction. Dermal fibroblasts incorporated [14C]-9-HODE and [14C]-13-HODE into phospholipids, mainly into phosphatidylcholine. IL-1beta increased significantly the esterification of 13-HODE in all glycerophospholipids, the major increase being observed in phosphatidylinositol. These results indicate that prostaglandin H-synthase-2 is the enzyme responsible for the increase in the ability to form HODEs of dermal fibroblasts stimulated with IL-1beta.
Godessart
N
N
Laboratory of Inflammation Mediators, Institute of Research of the Santa Creu i Sant Pau Hospital, Barcelona, Spain.
Camacho
M
M
López-Belmonte
J
J
Anton
R
R
García
M
M
de Moragas
J M
JM
Vila
L
L
D002478:Cells, Cultured; D005260:Female; D005347:Fibroblasts / Q000378:metabolism; D006801:Humans; D007375:Interleukin-1 / Q000494:pharmacology*; D019787:Linoleic Acid; D008041:Linoleic Acids / Q000096:biosynthesis* / Q000378:metabolism*; D044243:Linoleic Acids, Conjugated; D011451:Prostaglandin-Endoperoxide Synthases / Q000502:physiology*; D012867:Skin / Q000378:metabolism*
D007375:Interleukin-1; D008041:Linoleic Acids; D044243:Linoleic Acids, Conjugated; C024347:9-hydroxy-10,12-octadecadienoic acid; C024348:13-hydroxy-9,11-octadecadienoic acid; D019787:Linoleic Acid; D011451:Prostaglandin-Endoperoxide Synthases