IL-13 induces translocation of NF-kappaB in cultured human bronchial smooth muscle cells.
OBJECTIVE
Interleukin-13 (IL-13), a major Th2 cytokine, plays an important role in bronchial asthma, including mucus production, inflammation and airway hyperresponsiveness. Although IL-13 through its binding to IL-4 receptor alpha (IL-4Ralpha/IL-13Ralpha1 uses the canonical signal transducer and activator of transcription 6 (STAT6)-signaling pathway to mediate these tissue responses, recent studies have demonstrated that other signaling pathways may also be involved in. In the present study, whether IL-13 induces an activation of nuclear factor (NF)-kappaB, inflammatory transcription factor, was investigated in human bronchial smooth muscle cells (hBSMCs).


METHODS
Nuclear proteins were extracted from cultured hBSMCs treated with tumor necrosis factor (TNF)-alpha (10 ng/mL) or IL-13 (100 ng/mL), and assayed for activated NF-kappaB and STAT6 by Western blotting.


RESULTS
Treatments with TNF-alpha and IL-13 induced a translocation of NF-kappaB to nuclei in hBSMCs. In addition, coincubation with BMS-345541 (0.3 microM), an inhibitor of NF-kappaB (IkappaB) kinase (IKK) inhibitor, markedly inhibited the translocation of NF-kappaB.


CONCLUSIONS
Our results suggest for the first time that IL-13 activates NF-kappaB in hBSMCs.
Goto
Kumiko
K
Department of Pharmacology, School of Pharmacy, Hoshi University, 2-4-41 Ebara, Shinagawa-ku, Tokyo 142-8501, Japan.
Chiba
Yoshihiko
Y
Misawa
Miwa
M
D001980:Bronchi / Q000166:cytology*; D002467:Cell Nucleus / Q000378:metabolism; D006801:Humans; D018793:Interleukin-13 / Q000378:metabolism / Q000502:physiology*; D008954:Models, Biological; D032389:Myocytes, Smooth Muscle / Q000166:cytology*; D016328:NF-kappa B / Q000378:metabolism*; D010766:Phosphorylation; D021381:Protein Transport; D050800:STAT6 Transcription Factor / Q000378:metabolism; D015398:Signal Transduction; D018418:Th2 Cells / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
D018793:Interleukin-13; D016328:NF-kappa B; D050800:STAT6 Transcription Factor; C494101:STAT6 protein, human; D014409:Tumor Necrosis Factor-alpha