Retinoic acid induces PGI synthase expression in human endothelial cells.
Retinoic acid (RA) exhibits anti-inflammatory, anti-tumor, and immuno-modulatory actions, and affects angiogenesis and thrombosis. Arachidonic acid (AA) metabolites are involved in all these processes. We explored the effect of RA on AA metabolism in human umbilical vein endothelial cells (HUVECs). 13-cis-RA increased the release of prostaglandin I(2) (PGI(2)), both spontaneous and thrombin-induced, in terms of 6-oxo-PGF(1alpha) analyzed by enzyme-immunoassay. Coincubation with 13-cis-RA and interleukin-1beta resulted in a synergic increase in the release of PGI(2). Consistently, 13-cis-RA increased the ability of HUVECs to inhibit AA-induced platelet aggregation. 13-cis-RA did not induce cyclooxygenase-isoenzyme expression, determined by immunoblotting, or activity, evaluated by analyzing eicosanoids formed from exogenous labeled AA by HPLC. In contrast, RA induced PGI synthase (PGIS) activity and expression in terms of mRNA and protein determined by real-time PCR and Western blotting, respectively. Results from experiments with several species of RA and with retinoic acid receptor (RAR) and retinoid X receptor (RXR) antagonists showed that the effect of RA on PGIS expression was mediated by RAR. Actinomycin D and cycloheximide both inhibited RA-induced PGIS expression. Furthermore, RA increased PGIS transcriptional activity in transient transfection assays, an effect that was prevented by an RAR antagonist. These results reinforce the concept that RA could be beneficial for patients with cardiovascular risk.
Camacho
Mercedes
M
Angiology, Vascular Biology, and Inflammation Laboratory of the Institute of Research, Hospital Santa Creu i Sant Pau, Barcelona, Spain.
Rodríguez
Cristina
C
Salazar
Juliana
J
Martínez-González
José
J
Ribalta
Josep
J
Escudero
José-Román
JR
Masana
Lluís
L
Vila
Luis
L
D002478:Cells, Cultured; D003513:Cycloheximide / Q000494:pharmacology; D051545:Cyclooxygenase 1 / Q000096:biosynthesis; D051546:Cyclooxygenase 2 / Q000096:biosynthesis; D003577:Cytochrome P-450 Enzyme System / Q000096:biosynthesis*; D003609:Dactinomycin / Q000494:pharmacology; D004730:Endothelium, Vascular / Q000166:cytology / Q000187:drug effects / Q000201:enzymology*; D004790:Enzyme Induction; D011464:Epoprostenol / Q000378:metabolism; D006801:Humans; D019746:Intramolecular Oxidoreductases / Q000096:biosynthesis*; D015474:Isotretinoin / Q000494:pharmacology*
D003609:Dactinomycin; D003577:Cytochrome P-450 Enzyme System; D003513:Cycloheximide; D011464:Epoprostenol; D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2; D019746:Intramolecular Oxidoreductases; C022461:prostacyclin synthetase; D015474:Isotretinoin