[Involvement of MAPKs and NF-kappaB pathways in Pseudomonas pyocyanin-induced interleukin-8 expression by human airway epithelial cells].
To investigate the molecular mechanisms of signaling transduction by which Pseudomonas pyocyanin induces IL-8 expression in human airway epithelial cells, A549 and SPC-A-1 cells were challenged with P. aeruginosa conditioned medium or pyocyanin. Chemokine interleukin-8 (IL-8) release from the challenged cells was measured by ELISA, and Western blot was performed to analyze the degradation of IkappaB-alpha and the phosphorylation of MAPKs (mitogen-activated protein kinases) in the extracts from cells stimulated with pyocyanin. Both of P. aeruginosa conditioned medium and pyocyanin remarkably increased IL-8 expression by human airway epithelial cells. Degradation of IkappaB-alpha was found shortly after A549 cells were stimulated with pyocyanin. Western hybridization analysis also demonstrated that pyocyanin caused phosphorylation of MAPKs including ERK1/2, p38 and JNK in A549 cells. Pretreatment of A549 cells with U0126 (10 micromol/L), a selective inhibitor of MEK1/2 (ERK1/2 kinase) or with SB203580 (10 micromol/L), a specific inhibitor of p38 MAPK, diminished the pyocyanin-induced IL-8 production. These findings suggest that Pseudomonas pyocyanin can increase IL-8 expression by human airway epithelial cells through MAPKs signaling pathways and the activation of NF-kappaB is also involved in this process.
Feng
Yan
Y
Research Unit of Infection and Immunity, West China School of Preclinical and Forensic Medicine, Sichuan University, Chengdu 610041, China. fy575@163.com
Wang
Fang
F
Li
Xiang
X
Wang
Bo-yao
BY
Wu
Qi
Q
D002070:Butadienes / Q000494:pharmacology; D045744:Cell Line, Tumor; D004305:Dose-Response Relationship, Drug; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004847:Epithelial Cells / Q000378:metabolism; D006801:Humans; D007093:Imidazoles / Q000494:pharmacology; D016209:Interleukin-8 / Q000378:metabolism*; D020928:Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D016328:NF-kappa B / Q000378:metabolism*; D009570:Nitriles / Q000494:pharmacology; D010766:Phosphorylation; D011710:Pyocyanine / Q000494:pharmacology*; D011725:Pyridines / Q000494:pharmacology; D015398:Signal Transduction / Q000187:drug effects*
D002070:Butadienes; D004791:Enzyme Inhibitors; D007093:Imidazoles; D016209:Interleukin-8; D016328:NF-kappa B; D009570:Nitriles; D011725:Pyridines; C113580:U 0126; D011710:Pyocyanine; D020928:Mitogen-Activated Protein Kinases; C093642:SB 203580