Signalling pathway of isophorone diisocyanate-responsive interleukin-8 in airway smooth muscle cells.
This study is the first to analyse the soluble factors secreted by the bronchial epithelium after exposure to isophorone diisocyanate (IPDI) that are responsible for increasing migration and proliferation of primary normal human bronchial smooth muscle cells (BSMCs). We treated immortalised, nontumorigenic human bronchial epithelial cells (cell line BEAS-2B) and primary normal human bronchial epithelial cells (HBEC) with IPDI, and then collected the conditioned culture media (IPDI-BEAS-2B-CM and IPDI-HBEC-CM, respectively), which was added to BSMCs. Exposure of BEAS-2B cells and HBECs to IPDI increased interleukin (IL)-8 production. Culture of BSMCs with IPDI-BEAS-2B-CM and IPDI-HBEC-CM increased BSMC proliferation and migration, which are major features in asthma-related airway remodelling. Induction of BSMC proliferation and migration by IPDI-BEAS-2B-CM and IPDI-HBEC-CM was associated with increased focal adhesion kinase (FAK), Src, extracellular signal-regulated kinase (ERK)1/2 and AKT activation. Blocking FAK with a specific inhibitor significantly decreased BSMC migration and proliferation by inhibiting ERK1/2 activation. FAK and ERK1/2 inhibitor also decreased IPDI-BEAS-2B-CM-, IPDI-HBEC-CM- and recombinant human IL-8-mediated BSMC proliferation and migration, whereas blocking Rnd3 using small interfering RNA failed to affect BSMC proliferation, suggesting that Rnd3 was only involved in the regulation of BSMC migration. Our study suggests that inhibition of IL-8 or IL-8-mediated FAK/ERK/Rnd3 signalling is an attractive therapeutic target for IPDI-mediated asthma.
Kuo
P-L
PL
Institute of Clinical Medicine, Kaohsiung Medical University, Taiwan.
Huang
M-S
MS
Huang
S-K
SK
Ni
W-C
WC
Hung
J-Y
JY
Ko
Y-C
YC
Hung
C-H
CH
Tsai
Y-M
YM
Duh
T-H
TH
Hsu
Y-L
YL
D001980:Bronchi / Q000187:drug effects / Q000378:metabolism; D002460:Cell Line; D002465:Cell Movement / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D004791:Enzyme Inhibitors / Q000494:pharmacology; D051416:Focal Adhesion Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors / Q000096:biosynthesis; D006801:Humans; D016209:Interleukin-8 / Q000096:biosynthesis* / Q000378:metabolism*; D017953:Isocyanates / Q000494:pharmacology*; D019950:Mitogen-Activated Protein Kinase 1 / Q000096:biosynthesis; D048052:Mitogen-Activated Protein Kinase 3 / Q000096:biosynthesis; D009130:Muscle, Smooth / Q000187:drug effects*; D051057:Proto-Oncogene Proteins c-akt / Q000096:biosynthesis; D034741:RNA, Small Interfering / Q000494:pharmacology; D015398:Signal Transduction / Q000187:drug effects*; D020741:rho GTP-Binding Proteins / Q000037:antagonists & inhibitors / Q000096:biosynthesis; D019061:src-Family Kinases / Q000096:biosynthesis
D004791:Enzyme Inhibitors; D016209:Interleukin-8; D017953:Isocyanates; D034741:RNA, Small Interfering; C015301:isophorone diisocyanate; D051416:Focal Adhesion Protein-Tyrosine Kinases; D019061:src-Family Kinases; D051057:Proto-Oncogene Proteins c-akt; C535150:MAPK1 protein, human; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; C508705:RND3 protein, human; D020741:rho GTP-Binding Proteins