Influence of natural and recombinant interleukin 2 on endothelial cell arachidonate metabolism. Induction of de novo synthesis of prostaglandin H synthase.
We studied the effects of natural and recombinant human IL-2 (rIL-2) on secretion of prostacyclin (PGI2), vWf, and tissue-type plasminogen activator (tPA). IL-2 elicited a steady increase in PGI2 synthesis by cultured human umbilical vein endothelial cells (HUVECS) and bovine aortic endothelial cells but had no effect on vWf or tPA. Both purified natural IL-2 (nIL-2) and rIL-2 induced significant PGI2 synthesis. Substitution of the cysteine residue at position 125 of rIL-2 with serine or alanine led to loss of PGI2-stimulatory activity in HUVECS without affecting thymidine incorporation in lymphocytes. HPLC analysis of arachidonate metabolites detected predominantly 6 keto-PGF1 alpha (6KPGF1 alpha) peak. Treatment of cultured endothelial cells with cycloheximide and actinomycin D resulted in inhibition of 6KPGF1 alpha synthesis. The Western blot using a polyclonal antibody against PGH synthase revealed an increment in the 70-kD subunit of PGH synthase by nIL-2 and rIL-2, but not by alanine-substituted rIL-2. We conclude that IL-2 stimulated sustained PGI2 production by a mechanism that includes the de novo synthesis of PGH synthase. This mechanism for regulating AA metabolism probably has important physiologic implications.
D015121:6-Ketoprostaglandin F1 alpha / Q000096:biosynthesis; D000409:Alanine; D016718:Arachidonic Acid; D001095:Arachidonic Acids / Q000378:metabolism*; D015153:Blotting, Western; D002851:Chromatography, High Pressure Liquid; D003513:Cycloheximide / Q000494:pharmacology; D003545:Cysteine; D003609:Dactinomycin / Q000494:pharmacology; D004730:Endothelium, Vascular / Q000187:drug effects*; D004790:Enzyme Induction; D011464:Epoprostenol / Q000096:biosynthesis; D006801:Humans; D007376:Interleukin-2 / Q000494:pharmacology*; D008970:Molecular Weight; D011451:Prostaglandin-Endoperoxide Synthases / Q000096:biosynthesis*; D011994:Recombinant Proteins / Q000494:pharmacology; D012694:Serine; D013329:Structure-Activity Relationship; D010959:Tissue Plasminogen Activator / Q000378:metabolism; D014841:von Willebrand Factor / Q000378:metabolism
D001095:Arachidonic Acids; D007376:Interleukin-2; D011994:Recombinant Proteins; D014841:von Willebrand Factor; D003609:Dactinomycin; D016718:Arachidonic Acid; D012694:Serine; D015121:6-Ketoprostaglandin F1 alpha; D003513:Cycloheximide; D011464:Epoprostenol; D011451:Prostaglandin-Endoperoxide Synthases; D010959:Tissue Plasminogen Activator; D003545:Cysteine; D000409:Alanine