Cysteinyl leukotriene-1 receptor activation in a human bronchial epithelial cell line leads to signal transducer and activator of transcription 1-mediated eosinophil adhesion.
We studied the effect of leukotriene D(4) (LTD(4)) on a human bronchial epithelial cell line (16HBE) overexpressing the cysteinyl leukotriene (CysLT) (1) receptor (HBECysLT(1)R), looking at the associated signal transduction mechanisms as well as at effects on inflammatory cell adhesion. The results obtained showed that LTD(4) increases the phosphorylation of extracellular signal-regulated protein kinase (ERK) 1/2 and of the signal transducer and activator of transcription 1 (STAT-1) in serine 727 (STAT-1Ser727), resulting in increased eosinophil adhesion to HBECysLT(1)R, associated with enhanced surface expression of intercellular adhesion molecule (ICAM) 1. Pretreatment with a CysLT(1)R-selective antagonist or with a selective inhibitor of protein kinase C (PKC) or with a selective inhibitor of the mitogen-activated protein kinase kinase (MEK) successfully suppressed both LTD(4)-induced STAT-1Ser727 phosphorylation and the associated increase in eosinophil adhesion. The use of the MEK inhibitor and of the selective CysLT(1)R antagonist in electrophoretic mobility shift assay experiments showed that LTD(4) promotes the nuclear translocation of STAT-1 through the activation of ERK1/2 pathway. The key role of STAT-1 in leukotriene D(4) transduction signaling was confirmed by RNA interference experiments, where silencing of STAT-1 expression abolished the effect of leukotriene D(4) on eosinophil adhesion. In conclusion, for the first time, we provide evidence of the involvement of STAT-1 in the signal transduction mechanism of the CysLT(1) receptor; phosphorylation of STAT-1, through PKC and ERK1/2 activation, causes enhanced ICAM-1 surface expression and eosinophil adhesion. Effective CysLT(1)R antagonism may therefore contribute to the control of the chronic inflammatory condition that characterizes human airways in asthma.
Profita
Mirella
M
Institute of Biomedicine and Molecular Immunology, Italian National Research Council, Palermo, Italy.
Sala
Angelo
A
Bonanno
Anna
A
Siena
Liboria
L
Ferraro
Maria
M
Di Giorgi
Rossana
R
Montalbano
Angela M
AM
Albano
Giusy D
GD
Gagliardo
Rosalia
R
Gjomarkaj
Mark
M
D000085:Acetates / Q000494:pharmacology; D001980:Bronchi / Q000166:cytology; D002448:Cell Adhesion / Q000187:drug effects; D002460:Cell Line; D002478:Cells, Cultured; D003521:Cyclopropanes; D004804:Eosinophils / Q000166:cytology* / Q000187:drug effects; D004847:Epithelial Cells / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism*; D006801:Humans; D007211:Indoles / Q000494:pharmacology; D018799:Intercellular Adhesion Molecule-1 / Q000378:metabolism; D007371:Interferon-gamma / Q000494:pharmacology; D020024:Leukotriene Antagonists / Q000494:pharmacology; D017998:Leukotriene D4 / Q000494:pharmacology; D008301:Maleimides / Q000494:pharmacology; D008565:Membrane Proteins / Q000378:metabolism*; D020928:Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D011804:Quinolines / Q000494:pharmacology; D018077:Receptors, Leukotriene / Q000378:metabolism*; D050794:STAT1 Transcription Factor / Q000378:metabolism*; D013440:Sulfides
D000085:Acetates; D003521:Cyclopropanes; D007211:Indoles; D020024:Leukotriene Antagonists; D008301:Maleimides; D008565:Membrane Proteins; D011804:Quinolines; D018077:Receptors, Leukotriene; D050794:STAT1 Transcription Factor; D013440:Sulfides; D018799:Intercellular Adhesion Molecule-1; D017998:Leukotriene D4; D007371:Interferon-gamma; D020928:Mitogen-Activated Protein Kinases; C070515:bisindolylmaleimide I; C083169:leukotriene D4 receptor; C093875:montelukast