Interleukin-6 and mevastatin regulate plasminogen activator inhibitor-1 through CCAAT/enhancer-binding protein-delta.
OBJECTIVE
We sought to determine the etiologic mechanism of proinflammatory cytokine, interleukin-6 (IL-6), and statin as regulators of synthesis of plasminogen activator inhibitor-1 (PAI-1), the physiological fibrinolysis inhibitor and an acute-phase reactant.


RESULTS
Transient transfection and luciferase assay in HepG2 human hepatoma-derived cells demonstrated that IL-6 increased PAI-1 promoter activity and mevastatin decreased IL-6-inducible response. Systematic deletion assay of the promoter demonstrated that the region (-239 to -210 bp) containing a putative CCAAT/enhancer-binding protein (C/EBP) binding site was necessary. Point mutation in this site abolished the IL-6-inducible response. Electrophoretic mobility shift assay and chromatin immunoprecipitation assay demonstrated that C/EBPalpha, C/EBPbeta, and C/EBPdelta were involved in protein-DNA complex formation in intact cells. Deoxyribonuclease (DNase) I footprinting analysis revealed that 5' flanking region (-232 to -210 bp) is acute-phase response protein-binding site. C/EBPdelta binding activity was increased by IL-6 and attenuated by mevastatin. Mevastatin attenuated IL-6-mediated increase of C/EBPdelta protein in the nuclear extracts. IL-6 also increased PAI-1 and C/EBPdelta mRNA in mouse primary hepatocytes.


CONCLUSIONS
IL-6 increases hepatic PAI-1 expression mediated by the -232- to -210-bp region of the promoter containing a C/EBPdelta binding site. Vascular protection by statins may be partly mediated through regulation of CEBPdelta and consequent modulation of PAI-1 expression.
Dong
Jie
J
Department of Cardiovascular Medicine, Hokkaido University Graduate School of Medicine, Sapporo, Japan.
Fujii
Satoshi
S
Li
Hongmei
H
Nakabayashi
Hidekazu
H
Sakai
Masaharu
M
Nishi
Shinzo
S
Goto
Daisuke
D
Furumoto
Tomoo
T
Imagawa
Shogo
S
Zaman
Tarikuz A K M
TA
Kitabatake
Akira
A
D000818:Animals; D050197:Atherosclerosis / Q000188:drug therapy / Q000503:physiopathology; D051743:CCAAT-Enhancer-Binding Protein-delta / Q000235:genetics / Q000378:metabolism*; D006528:Carcinoma, Hepatocellular; D045744:Cell Line, Tumor; D002467:Cell Nucleus / Q000502:physiology; D002874:Chromosome Mapping; D015870:Gene Expression / Q000187:drug effects / Q000502:physiology; D022781:Hepatocytes / Q000187:drug effects / Q000502:physiology; D006801:Humans; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors / Q000494:pharmacology*; D015850:Interleukin-6 / Q000235:genetics / Q000378:metabolism*; D008113:Liver Neoplasms; D008148:Lovastatin / Q000031:analogs & derivatives* / Q000494:pharmacology; D051379:Mice; D008813:Mice, Inbred ICR; D016297:Mutagenesis, Site-Directed; D017395:Plasminogen Activator Inhibitor 1 / Q000235:genetics* / Q000378:metabolism; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000378:metabolism; D020218:Response Elements; D013927:Thrombosis / Q000503:physiopathology; D014162:Transfection
D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors; D015850:Interleukin-6; D017395:Plasminogen Activator Inhibitor 1; D012333:RNA, Messenger; D051743:CCAAT-Enhancer-Binding Protein-delta; C012258:mevastatin; D008148:Lovastatin