Interleukin 1beta decreases prostacyclin synthase activity in rat mesangial cells via endogenous peroxynitrite formation.
We have reported that peroxynitrite (PON) selectively inactivated prostacyclin synthase (PGIS) by a mechanism of tyrosine nitration at the active site [Zou, Martin and Ullrich (1997) Biol. Chem. Hoppe-Seyler 378, 707-713]. We have now extended our studies on rat mesangial cells (RMC) and show that nitration can occur under the influence of cytokines. Pretreatment of RMC with interleukin 1beta (IL-1beta), which up-regulated cyclo-oxygenase 2 and inducible nitric oxide synthase (NOS-2), significantly attenuated the conversion of [14C]prostaglandin H2 (PGH2) into the stable prostacyclin (PGI2) metabolite 6-oxo-prostaglandin F1alpha (6-oxo-PGF1alpha). The presence of superoxide dismutase (SOD, 100 units/ml) or the NOS synthase inhibitor Nomega-monomethyl-l-arginine (100 microM) as well as cycloheximide (10 microM) plus actinomycin (10 microM) abolished IL-1beta-mediated down-regulation of 6-oxo-PGF1alpha from PGH2. At the same time, 6-oxo-PGF1alpha production from arachidonate (AA) increased at the expense of prostaglandin E2 (PGE2). Neither NO alone generated from different NO donors nor superoxide from xanthine/xanthine oxidase (1-100 m-units/ml) inhibited PGI2 synthesis, either from PGH2 or from AA. Bolus additions of chemically synthesized PON or the PON generator 3-morpholinosydnonimine N-ethylcarbamide (SIN-1) exhibited a potent inhibition of 6-oxo-PGF1alpha release from both PGH2 and AA. In addition, immunoprecipitation of nitrotyrosine-containing proteins from PON- and SIN-1-treated RMC yielded distinct nitrated PGIS bands but also from IL-1beta-pretreated cells alone, compared with a lack of nitrated PGIS in control cells. Taken together, our results strongly suggest that IL-1beta pretreatment of RMC via NOS-2 leads to the production of PON with the consequence of a partial nitration and inhibition of PGIS.
Zou
M H
MH
Faculty of Biology, University of Konstanz, Fach X910-Sonnenbühl, D-78434 Konstanz, Germany.
Klein
T
T
Pasquet
J P
JP
Ullrich
V
V
D000818:Animals; D000975:Antioxidants / Q000494:pharmacology; D016718:Arachidonic Acid / Q000378:metabolism / Q000494:pharmacology; D002614:Chelating Agents / Q000494:pharmacology; D003577:Cytochrome P-450 Enzyme System / Q000187:drug effects / Q000378:metabolism*; D016166:Free Radical Scavengers / Q000494:pharmacology; D005920:Glomerular Mesangium / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D007375:Interleukin-1 / Q000494:pharmacology*; D019746:Intramolecular Oxidoreductases / Q000187:drug effects / Q000378:metabolism*; D009566:Nitrates / Q000378:metabolism* / Q000494:pharmacology; D009569:Nitric Oxide / Q000378:metabolism; D044262:Prostaglandin H2; D011463:Prostaglandins H / Q000378:metabolism; D051381:Rats; D013482:Superoxide Dismutase / Q000378:metabolism / Q000494:pharmacology; D019323:omega-N-Methylarginine / Q000494:pharmacology
D000975:Antioxidants; D002614:Chelating Agents; D016166:Free Radical Scavengers; D007375:Interleukin-1; D009566:Nitrates; D011463:Prostaglandins H; C039642:peroxynitric acid; D019323:omega-N-Methylarginine; D016718:Arachidonic Acid; D009569:Nitric Oxide; D044262:Prostaglandin H2; D003577:Cytochrome P-450 Enzyme System; D013482:Superoxide Dismutase; D019746:Intramolecular Oxidoreductases; C022461:prostacyclin synthetase