Please use this identifier to cite or link to this item: http://hdl.handle.net/2445/176796
Title: Induction of COX-2 enzyme and down-regulation of COX-1 expression by lipopolysaccharide (LPS) control prostaglandin E2 production in astrocytes
Author: Font Nieves de La Vega, Miriam Aurora
Sans Fons, Gloria
Gorina Méndez, Roser
Bonfill-Teixidor, Ester
Salas Perdomo, Angélica María
Márquez-Kisinousky, Leonardo
Santalucía Albi, Tomàs
Planas Obradors, Anna Maria
Keywords: Astròcits
Enzimologia
Metabolisme
Proteïnes de membrana
Astrocytes
Enzymology
Metabolism
Membrane proteins
Issue Date: 24-Feb-2012
Publisher: American Society for Biochemistry and Molecular Biology
Abstract: Pathological conditions and pro-inflammatory stimuli in the brain induce cyclooxygenase-2 (COX-2), a key enzyme in arachidonic acid metabolism mediating the production of prostanoids that, among other actions, have strong vasoactive properties. Although low basal cerebral COX-2 expression has been reported, COX-2 is strongly induced by pro-inflammatory challenges, whereas COX-1 is constitutively expressed. However, the contribution of these enzymes in prostanoid formation varies depending on the stimuli and cell type. Astrocyte feet surround cerebral microvessels and release molecules that can trigger vascular responses. Here, we investigate the regulation of COX-2 induction and its role in prostanoid generation after a pro-inflammatory challenge with the bacterial lipopolysaccharide (LPS) in astroglia. Intracerebral administration of LPS in rodents induced strong COX-2 expression mainly in astroglia and microglia, whereas COX-1 expression was predominant in microglia and did not increase. In cultured astrocytes, LPS strongly induced COX-2 and microsomal prostaglandin-E2 (PGE2) synthase-1, mediated by the MyD88-dependent NFκB pathway and influenced by mitogen-activated protein kinase pathways. Studies in COX-deficient cells and using COX inhibitors demonstrated that COX-2 mediated the high production of PGE2 and, to a lesser extent, other prostanoids after LPS. In contrast, LPS down-regulated COX-1 in an MyD88-dependent fashion, and COX-1 deficiency increased PGE2 production after LPS. The results show that astrocytes respond to LPS by a COX-2-dependent production of prostanoids, mainly vasoactive PGE2, and suggest that the coordinated down-regulation of COX-1 facilitates PGE2 production after TLR-4 activation. These effects might induce cerebral blood flow responses to brain inflammation.
Note: Reproducció del document publicat a: https://doi.org/10.1074/jbc.M111.327874
It is part of: Journal of Biological Chemistry, 2012, vol. 287, num. 9, p. 6454-6468
URI: http://hdl.handle.net/2445/176796
Related resource: https://doi.org/10.1074/jbc.M111.327874
ISSN: 0021-9258
Appears in Collections:Articles publicats en revistes (IDIBAPS: Institut d'investigacions Biomèdiques August Pi i Sunyer)
Articles publicats en revistes (Infermeria Fonamental i Medicoquirúrgica)
Articles publicats en revistes (Medicina)
Articles publicats en revistes (Institut de Recerca Biomèdica (IRB Barcelona))

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