title: Upregulation of COX-2 in cerebral microvascular endothelial cells by smooth muscle cell signals.
abstract: Cyclooxygenase (COX) isoform expression, intracellular localization, and function in endothelial cells from the newborn pig cerebral microvessels were investigated using COX-1- and COX-2-specific antibodies and the COX-2 inhibitor NS-398. Cerebral microvessels, microvascular endothelium, and cultured endothelial cells constitutively express both COX-1 and COX-2. NS-398 inhibits 70-90% of endothelial prostanoid production. Endothelial cells grown in noncontact coculture with smooth muscle cells for 24-48 h demonstrate a stable induction of COX-2 protein and an NS-398-sensitive increase in prostanoid synthesis. The induction of endothelial COX in mixed cell coculture is accompanied by intracellular redistribution of COX-2. In cocultured endothelial cells, COX-2 is observed in the nucleus, nuclear envelope, and cytoplasm, compared with the mainly intranuclear localization of COX-2 in cells cultured separately. No changes were observed in COX-1 protein, localized in endothelial cell cytoplasm and the nuclear envelope. These results indicate that smooth muscle cells may modify endothelial function by upregulating COX-2, which is a major functional COX isoform in cerebral microvascular endothelial cells.
authors.affiliation: Department of Physiology and Biophysics, University of Tennessee, Memphis 38163, USA.
authors.forename: H
authors.initials: H
authors.lastname: Parfenova
authors.forename: T H
authors.initials: TH
authors.lastname: Eidson
authors.forename: C W
authors.initials: CW
authors.lastname: Leffler
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D016718:Arachidonic Acid / Q000494:pharmacology; D001921:Brain / Q000098:blood supply; D002467:Cell Nucleus / Q000201:enzymology; D002478:Cells, Cultured; D002560:Cerebrovascular Circulation; D018920:Coculture Techniques; D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2; D052246:Cyclooxygenase 2 Inhibitors; D016861:Cyclooxygenase Inhibitors / Q000494:pharmacology; D003600:Cytosol / Q000201:enzymology; D003907:Dexamethasone / Q000494:pharmacology; D015232:Dinoprostone / Q000494:pharmacology; D004730:Endothelium, Vascular / Q000166:cytology / Q000201:enzymology*; D004790:Enzyme Induction / Q000187:drug effects; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D015759:Ionomycin / Q000494:pharmacology; D007527:Isoenzymes / Q000096:biosynthesis*; D007700:Kinetics; D008833:Microcirculation; D009578:Nitrobenzenes / Q000494:pharmacology; D011451:Prostaglandin-Endoperoxide Synthases / Q000096:biosynthesis*; D011453:Prostaglandins / Q000378:metabolism; D013449:Sulfonamides / Q000494:pharmacology; D013552:Swine
chemical_list: D052246:Cyclooxygenase 2 Inhibitors; D016861:Cyclooxygenase Inhibitors; D007527:Isoenzymes; D009578:Nitrobenzenes; D011453:Prostaglandins; D013449:Sulfonamides; C080955:N-(2-cyclohexyloxy-4-nitrophenyl)methanesulfonamide; D016718:Arachidonic Acid; D015759:Ionomycin; D003907:Dexamethasone; D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2; D011451:Prostaglandin-Endoperoxide Synthases; D015232:Dinoprostone