Interleukin-13-induced activation of signal transducer and activator of transcription 6 is mediated by an activation of Janus kinase 1 in cultured human bronchial smooth muscle cells.
BACKGROUND
The current study was carried out to identify the JAK molecule(s) that is involved in the IL-13-induced activation of STAT6 in cultured human bronchial smooth muscle cells (hBSMCs).


METHODS
Cultured hBSMCs were stimulated with IL-13 in the absence and presence of JAK inhibitor-I (a nonspecific JAKs inhibitor), tyrphostin-AG490 (a specific JAK2 inhibitor), WHI-P131 (a specific JAK3 inhibitor), or tyrphostin-AG9 (a specific Tyk2 inhibitor), and levels of phosphorylated STAT6 were measured by immunoblot analyses.


RESULTS
The IL-13-induced phosphorylation of STAT6 was abolished by JAK inhibitor-I, whereas the other inhibitors had no significant effect.


CONCLUSIONS
These findings indicate that the STAT6 phosphorylation/activation induced by IL-13 is mediated by an activation of JAK1 in cultured hBSMCs.
Department of Biology, School of Pharmacy, Hoshi University, 2-4-41 Ebara, Shinagawa-ku, Tokyo 142-8501, Japan. chiba@hoshi.ac.jp
Yoshihiko
Y
Chiba
Kumiko
K
Goto
Miwa
M
Misawa
D001980:Bronchi / Q000166:cytology / Q000187:drug effects / Q000276:immunology / Q000378:metabolism*; D016535:Bronchial Hyperreactivity / Q000276:immunology / Q000378:metabolism; D002478:Cells, Cultured; D004789:Enzyme Activation; D006801:Humans; D018793:Interleukin-13 / Q000494:pharmacology* / Q000502:physiology; D053613:Janus Kinase 1 / Q000037:antagonists & inhibitors / Q000378:metabolism*; D009130:Muscle, Smooth / Q000166:cytology / Q000187:drug effects / Q000276:immunology / Q000378:metabolism*; D010766:Phosphorylation; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D050800:STAT6 Transcription Factor / Q000378:metabolism*
D018793:Interleukin-13; D047428:Protein Kinase Inhibitors; D050800:STAT6 Transcription Factor; C494101:STAT6 protein, human; C507904:JAK1 protein, human; D053613:Janus Kinase 1