Objective To confirm if pulmonary epithelial cells express Toll-like receptor 4 （TLR4） and investigate the role of TLR4 in airway inflammation of chronic obstructive pulmonary diseases （COPD）. Methods The expressi...Objective To confirm if pulmonary epithelial cells express Toll-like receptor 4 （TLR4） and investigate the role of TLR4 in airway inflammation of chronic obstructive pulmonary diseases （COPD）. Methods The expressions of TLR4, IL-8 mRNA and NF-KB activation stimulated by differen factors E lipopolysacharides （LPS）, interleukin-lβ, cigarette smoking extract （CSE）] in pulmonary epithelial cells were investigated. Results LPS, CSE and IL-lβ induced the production of IL-8 and activation of NF-KB. The levels of 1L-8 mRNA and NF-KB protein in E1A ＋ cell were markedly higher than E1A- cell and A549 cell （ P 〈0. 05）. The TLR4 mRNA of all the cells increased along with the increase of LPS＇ stimulated time. There was significant difference among different LPS＇ doses （ 12 h： P = O. 039 ; 24 h ： P = O. 013 ）. The TLR4 mRNA of E1A ＋ cell was higher than the other two groups （ P 〈0. 05）. IL-lβ induced all the cells expressing TLR4 mRNA. CSE had no effect on the expression of TLR4 mRNA. Conclusion Pulmonary epithelial cells express TLR4. LPS and IL-lβ up-regulate IL-8 mediated via the activation of NF-KB induced by TLR4. But CSE up-regulates IL-8 mediated via the activation of NF-KB, which has no relation to TLR4 and may have another signal transduction pathway.展开更多
文摘Objective To confirm if pulmonary epithelial cells express Toll-like receptor 4 （TLR4） and investigate the role of TLR4 in airway inflammation of chronic obstructive pulmonary diseases （COPD）. Methods The expressions of TLR4, IL-8 mRNA and NF-KB activation stimulated by differen factors E lipopolysacharides （LPS）, interleukin-lβ, cigarette smoking extract （CSE）] in pulmonary epithelial cells were investigated. Results LPS, CSE and IL-lβ induced the production of IL-8 and activation of NF-KB. The levels of 1L-8 mRNA and NF-KB protein in E1A ＋ cell were markedly higher than E1A- cell and A549 cell （ P 〈0. 05）. The TLR4 mRNA of all the cells increased along with the increase of LPS＇ stimulated time. There was significant difference among different LPS＇ doses （ 12 h： P = O. 039 ; 24 h ： P = O. 013 ）. The TLR4 mRNA of E1A ＋ cell was higher than the other two groups （ P 〈0. 05）. IL-lβ induced all the cells expressing TLR4 mRNA. CSE had no effect on the expression of TLR4 mRNA. Conclusion Pulmonary epithelial cells express TLR4. LPS and IL-lβ up-regulate IL-8 mediated via the activation of NF-KB induced by TLR4. But CSE up-regulates IL-8 mediated via the activation of NF-KB, which has no relation to TLR4 and may have another signal transduction pathway.
