CysLT1 receptor engagement induces activator protein-1- and NF-kappaB-dependent IL-8 expression.
Because cysteinyl-leukotrienes (cysLTs) are major protagonists in the pathophysiology of human asthma, and because neutrophils are involved in the more severe form of asthma, we studied the potential for leukotriene (LT) D(4) to induce synthesis of the chemokine IL-8 through activation of the CysLT1 receptor. We found LTD(4) to induce IL-8 gene expression in monocytic THP-1 cells and human dendritic cells with complete abrogation by selective CysLT1 antagonists. Human embryonic kidney-293 cells stably transfected with CysLT1 were used to better study the transcriptional regulation of the IL-8 promoter. Stimulation of the cells with graded concentrations of LTD(4) resulted in a time- and concentration-dependent induction of IL-8 transcription and protein synthesis. Use of IL-8 promoter mutants with substitutions in their NF-kappaB, activator protein (AP)-1, and NF-IL-6 binding elements revealed a requirement for NF-kappaB and AP-1, but not NF-IL-6, in LTD(4)-induced activation of the IL-8 promoter. Overexpression of dominant-negative IkappaBalpha inhibited the IL-8 transactivation induced by LTD(4). NF-kappaB DNA binding activity was induced by LTD(4), as determined by electrophoretic mobility shift assays, and could be supershifted by antibodies against p50 and p65. Supershift assays after LTD(4) stimulation also indicated the formation of a c-Jun/c-Fos complex. Moreover, our results demonstrate that LTD(4) upregulates the expression of c-fos and c-jun at the mRNA level. Our data show for the first time that LTD(4), via the CysLT1 receptor, can transcriptionally activate IL-8 production, with involvement of the transcription factors p50, p65, Fos, and Jun. These findings provide mechanistic and potentially therapeutic elements for modulation of the inflammatory component of asthma.
Thompson
Charles
C
Immunology Division, Department of Pediatrics, Faculty of Medicine, Université de Sherbrooke, 3001 North 12th Avenue, Sherbrooke, PQ, Canada.
Cloutier
Alexandre
A
Bossé
Ynuk
Y
Thivierge
Maryse
M
Gouill
Christian Le
CL
Larivée
Pierre
P
McDonald
Patrick P
PP
Stankova
Jana
J
Rola-Pleszczynski
Marek
M
D001249:Asthma / Q000378:metabolism; D002460:Cell Line; D004247:DNA / Q000187:drug effects / Q000378:metabolism; D003713:Dendritic Cells / Q000187:drug effects / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D006801:Humans; D016209:Interleukin-8 / Q000096:biosynthesis* / Q000235:genetics; D017998:Leukotriene D4 / Q000378:metabolism / Q000494:pharmacology*; D008565:Membrane Proteins / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism; D009000:Monocytes / Q000187:drug effects / Q000378:metabolism; D009154:Mutation; D052002:NF-kappa B p50 Subunit / Q000235:genetics / Q000378:metabolism*; D011401:Promoter Regions, Genetic / Q000187:drug effects; D011485:Protein Binding; D016760:Proto-Oncogene Proteins c-fos / Q000378:metabolism; D016755:Proto-Oncogene Proteins c-jun / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D018077:Receptors, Leukotriene / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism; D013997:Time Factors; D018808:Transcription Factor AP-1 / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic / Q000187:drug effects*; D014162:Transfection
D016209:Interleukin-8; D008565:Membrane Proteins; D052002:NF-kappa B p50 Subunit; C489548:NFKB1 protein, human; D016760:Proto-Oncogene Proteins c-fos; D016755:Proto-Oncogene Proteins c-jun; D012333:RNA, Messenger; D018077:Receptors, Leukotriene; D018808:Transcription Factor AP-1; D017998:Leukotriene D4; D004247:DNA; C083169:leukotriene D4 receptor