Interleukin-10 suppresses tissue factor expression in lipopolysaccharide-stimulated macrophages via inhibition of Egr-1 and a serum response element/MEK-ERK1/2 pathway.
Atherosclerosis is considered to be an inflammatory disease. Tissue factor (TF), a prothrombotic molecule expressed by various cell types within atherosclerotic plaques, is thought to play an essential role in thrombus formation after atherosclerotic plaque rupture. Recent studies suggest that the antiinflammatory cytokine interleukin-10 (IL-10) has many antiatherosclerotic properties. Therefore, the effects of IL-10 on TF expression in response to inflammation were investigated. Mouse macrophages were stimulated with lipopolysaccharide (LPS) in the presence or absence of IL-10. Pretreatment with IL-10 resulted in a 50% decrease in TF mRNA expression and TF promoter activity. Binding of early growth response gene-1 (Egr-1) to the consensus DNA sequence, a key transcriptional activator of TF expression in response to inflammation, and the expression of Egr-1 mRNA were also inhibited by IL-10. This inhibition was independent of the induction of suppressor of cytokine signaling protein-3 by IL-10. Macrophages that had been transfected with luciferase reporter constructs containing the murine Egr-1 5'-flanking sequence exhibited reduced reporter gene activity in response to LPS stimulation with IL-10 pretreatment. Studies with deletion constructs of the Egr-1 promoter identified the proximal serum response element SRE3 as a potential regulatory site for the IL-10 mediated suppression of Egr-1 expression. Furthermore, activation of the upstream signal-transduction elements, such as mitogen-activated protein kinase kinase (MEK) 1/2, extracellular signal-regulated kinase 1/2, and Elk-1 were also inhibited by IL-10 pretreatment. Taken together, these results demonstrate a pathway for the IL-10 mediated inhibition of TF expression during inflammation and may explain the antiatherosclerotic effects of IL-10.
Kamimura
Motohiro
M
Department Internal Medicine III, University of Heidelberg, Heidelberg, Germany.
Viedt
Christiane
C
Dalpke
Alexander
A
Rosenfeld
Michael E
ME
Mackman
Nigel
N
Cohen
David M
DM
Blessing
Erwin
E
Preusch
Michael
M
Weber
Christian M
CM
Kreuzer
Jörg
J
Katus
Hugo A
HA
Bea
Florian
F
D000818:Animals; D002478:Cells, Cultured; D004268:DNA-Binding Proteins / Q000037:antagonists & inhibitors* / Q000235:genetics; D051766:Early Growth Response Protein 1; D017874:Immediate-Early Proteins / Q000037:antagonists & inhibitors* / Q000235:genetics; D016753:Interleukin-10 / Q000494:pharmacology*; D008070:Lipopolysaccharides / Q000494:pharmacology*; D048369:MAP Kinase Kinase 1 / Q000502:physiology*; D048370:MAP Kinase Kinase 2 / Q000502:physiology*; D008264:Macrophages / Q000378:metabolism*; D051379:Mice; D008810:Mice, Inbred C57BL; D019950:Mitogen-Activated Protein Kinase 1 / Q000502:physiology*; D048052:Mitogen-Activated Protein Kinase 3 / Q000502:physiology*; D010766:Phosphorylation; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000032:analysis; D011971:Receptors, Immunologic / Q000502:physiology; D012097:Repressor Proteins / Q000502:physiology; D027602:Serum Response Element / Q000502:physiology*; D000071223:Suppressor of Cytokine Signaling 3 Protein; D050826:Suppressor of Cytokine Signaling Proteins; D013925:Thromboplastin / Q000235:genetics*; D051197:Toll-Like Receptor 4; D014157:Transcription Factors / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000502:physiology
D004268:DNA-Binding Proteins; D051766:Early Growth Response Protein 1; C486109:Egr1 protein, mouse; D017874:Immediate-Early Proteins; D008070:Lipopolysaccharides; D012333:RNA, Messenger; D011971:Receptors, Immunologic; D012097:Repressor Proteins; C106644:SOCS3 protein, human; D000071223:Suppressor of Cytokine Signaling 3 Protein; D050826:Suppressor of Cytokine Signaling Proteins; C493487:Tlr4 protein, mouse; D051197:Toll-Like Receptor 4; D014157:Transcription Factors; D016753:Interleukin-10; D013925:Thromboplastin; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D048369:MAP Kinase Kinase 1; D048370:MAP Kinase Kinase 2; C482127:Map2k1 protein, mouse; C482129:Map2k2 protein, mouse