Signaling by the cysteinyl-leukotriene receptor 2. Involvement in chemokine gene transcription.
Cysteinyl-leukotrienes are involved in inflammation and act on at least two G-protein-coupled receptors, CysLT1 and CysLT2. However, the role of the CysLT2 receptor as well as its signaling remain poorly understood. Here we show that leukotriene (LT)C(4) induced the production of the chemokine interleukin (IL)-8 in endothelial cells. To further study the signaling cascade involved, HEK293 cells were stably transfected with CysLT2 and used to study the transcriptional regulation of the IL-8 promoter. Stimulation of the cells with increasing concentrations of LTC(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, AP-1, or NF-IL-6 binding elements revealed an almost total requirement for NF-kappaB and AP-1 elements, and a lesser requirement for the NF-IL-6 element. Overexpression of dominant-negative IkappaBalpha prevented the IL-8 transactivation induced by LTC(4). LTC(4) stimulation induced NF-kappaB and AP-1 DNA binding, which involved the formation of a p50/p65 and a c-JUN.c-FOS complex, respectively. Transfection of the cells with a dominant negative (dn) form of PKCepsilon prevented p65 phosphorylation, whereas dnPKCdelta prevented AP-1 binding. Moreover, dnPKCdelta, dnPKCepsilon, and dnPKCzeta prevented LTC(4)-induced IL-8 transcription in response to LTC(4). Our data show for the first time that LTC(4) can act via the CysLT2 receptor to transcriptionally activate chemokine production through induction of NF-kappaB and AP-1 transcription factors. These findings suggest the potential implication of CysLT2 in the inflammatory response through the modulation of chemokine gene transcription.
Immunology Division, Department of Pediatrics, Université de Sherbrooke, Sherbrooke, Quebec J1H 5N4, Canada.
Charles
C
Thompson
Alexandre
A
Cloutier
Ynuk
Y
Bossé
Caroline
C
Poisson
Pierre
P
Larivée
Patrick P
PP
McDonald
Jana
J
Stankova
Marek
M
Rola-Pleszczynski
D002460:Cell Line; D016762:Genes, fos / Q000502:physiology; D006801:Humans; D051550:I-kappa B Kinase / Q000235:genetics / Q000378:metabolism; D007249:Inflammation / Q000235:genetics / Q000378:metabolism; D016209:Interleukin-8 / Q000096:biosynthesis* / Q000235:genetics; D017997:Leukotriene C4 / Q000378:metabolism*; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D052002:NF-kappa B p50 Subunit / Q000235:genetics / Q000378:metabolism; D051745:Protein Kinase C-delta / Q000235:genetics / Q000378:metabolism; D051744:Protein Kinase C-epsilon / Q000235:genetics / Q000378:metabolism; D016755:Proto-Oncogene Proteins c-jun / Q000235:genetics / Q000378:metabolism; D018077:Receptors, Leukotriene / Q000235:genetics / Q000378:metabolism*; D020218:Response Elements / Q000235:genetics; D015398:Signal Transduction / Q000502:physiology*; D051996:Transcription Factor RelA / Q000235:genetics / Q000378:metabolism; D014158:Transcription, Genetic / Q000502:physiology*
C508606:CXCL8 protein, human; D016209:Interleukin-8; D008565:Membrane Proteins; D052002:NF-kappa B p50 Subunit; D016755:Proto-Oncogene Proteins c-jun; D018077:Receptors, Leukotriene; D051996:Transcription Factor RelA; D017997:Leukotriene C4; C412375:cysteinyl leukotriene receptor 2; D051550:I-kappa B Kinase; D051745:Protein Kinase C-delta; D051744:Protein Kinase C-epsilon; C083169:leukotriene D4 receptor