title: Down-regulation of endothelial cell estrogen receptor expression by the inflammation promoter LPS.
abstract: Endothelial cells express both estrogen receptor (ER) alpha and beta. The objective of this study was to investigate if and how mediators of inflammation regulate endothelial cell ERalpha and ERbeta expression. ERalpha and ERbeta transcript and protein expression were determined by real-time quantitative PCR and Western blotting, respectively, in endothelial cell line bEnd.3 cells stimulated with the inflammation promoter lipopolysaccharide (E. coli LPS). Stimulation with LPS (500 ng/ml and 10 microg/ml) for 4 days reduced both ERalpha and ERbeta mRNA levels. The glucocorticoid dexamethasone (1 microM) had no effect on LPS-induced attenuation of ERalpha and beta transcript expression. Full-length 66-67 kDa ERalpha protein was unaffected by 4 days stimulation with LPS, while the 46-kDa ERalpha isoform was reduced by about 20%. ERbeta protein was reduced by about 40% by LPS at 4 days. Treatment with 17beta-estradiol (E(2), 100 nM) for 4 days increased ERbeta mRNA by about 8 times but had no effect on ERalpha mRNA level. The E(2)-induced increase in ERbeta transcript was not associated with increased ERbeta protein. E(2) increased ERbeta mRNA expression also in the presence of LPS, suggesting that inflammation-induced impairment of ERbeta signalling is rescued by estrogen.
authors.affiliation: Department of Experimental Medical Science, Lund University, Lund, Sweden.
authors.forename: Anders
authors.initials: A
authors.lastname: Holm
authors.forename: Kristina E
authors.initials: KE
authors.lastname: Andersson
authors.forename: Ina
authors.initials: I
authors.lastname: Nordström
authors.forename: Per
authors.initials: P
authors.lastname: Hellstrand
authors.forename: Bengt-Olof
authors.initials: BO
authors.lastname: Nilsson
mesh_terms: D000818:Animals; D015153:Blotting, Western; D002460:Cell Line; D002478:Cells, Cultured; D003907:Dexamethasone / Q000494:pharmacology; D015536:Down-Regulation / Q000187:drug effects*; D042783:Endothelial Cells / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D047628:Estrogen Receptor alpha / Q000235:genetics / Q000378:metabolism*; D047629:Estrogen Receptor beta / Q000235:genetics / Q000378:metabolism*; D005786:Gene Expression Regulation / Q000187:drug effects; D005938:Glucocorticoids / Q000494:pharmacology; D007249:Inflammation / Q000235:genetics / Q000378:metabolism*; D008070:Lipopolysaccharides / Q000494:pharmacology*; D051379:Mice; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D047628:Estrogen Receptor alpha; D047629:Estrogen Receptor beta; D005938:Glucocorticoids; D008070:Lipopolysaccharides; D020033:Protein Isoforms; D012333:RNA, Messenger; D003907:Dexamethasone