[Effects of polymixin B on I-kappaB kinase mRNA expression in lipopolysaccharide- induced pulmonary alveolar macrophages].
OBJECTIVE
To investigate effects of polymixin B (PMB) on I-kappaB kinase(IKK-beta), inhibitor protein(IkappaB-alpha) and nuclear factor-kappa B(NF-kappaB) in lipopolysaccharide(LPS)-induced pulmonary alveolar macrophages (PAM), and explore the anti-inflammatory mechanism of PMB.


METHODS
PAM from rats collected by bronchoalveolar lavage was cultured and divided into three groups. In the control group, PAM was not stimulated with LPS and not treated with PMB. In the LPS stimulated group, PAM was stimulated with LPS. In the PMB treated group, PAM was pretreated with PMB half an hour prior to LPS stimulation. The expression of IKK-beta mRNA, level of IkappaB-alpha and the activity of NF-kappaB in PAM were measured by in situ hybridization(ISH), enzyme linked immunoadsorbent assay (ELISA) and electrophoretic mobility shift assay(EMSA), respectively.


RESULTS
In the LPS stimulated group, the expression of IKK-beta mRNA (0.147+/-0.015) and activity of NF-kappaB (0.828+/-0.019) in PAM significantly increased, whereas levels of IkappaB-alpha (0.228+/-0.021) decreased (all P<0.01) in PMB treated groups. The expression of IKK-beta mRNA (0.112+/-0.022) and activity of NF-kappaB (0.358+/-0.011) were down-regulated while level of IkappaB-alpha (0.477+/-0.016) was up-regulated(P<0.01).


CONCLUSIONS
LPS might induce expression of IKK-beta mRNA, degradation of IkappaB-alpha and activation of NF-kappaB PMB could inhibit the expression of IKK-beta, degradation of IkappaB-alpha and activation of NF-kappaB, showing marked anti-inflammatory property.
Yin
Wen
W
Department of Emergency, Xijing Hospital, The Fourth Military Medical University, Xi'an 710032, Shanxi, China.
Yang
Jian-hong
JH
Hu
Xiao-min
XM
Yuan
Jing
J
Luo
Yan-jun
YJ
Li
Yue-cai
YC
D000818:Animals; D051550:I-kappa B Kinase / Q000378:metabolism*; D020672:I-kappa B Proteins / Q000378:metabolism; D008070:Lipopolysaccharides / Q000009:adverse effects; D008168:Lung / Q000166:cytology / Q000187:drug effects; D016676:Macrophages, Alveolar / Q000187:drug effects* / Q000378:metabolism*; D000072000:NF-KappaB Inhibitor alpha; D016328:NF-kappa B / Q000378:metabolism; D011112:Polymyxin B / Q000494:pharmacology*; D012333:RNA, Messenger / Q000235:genetics; D051381:Rats; D017208:Rats, Wistar
D020672:I-kappa B Proteins; D008070:Lipopolysaccharides; D016328:NF-kappa B; C000606206:Nfkbia protein, rat; D012333:RNA, Messenger; D000072000:NF-KappaB Inhibitor alpha; D051550:I-kappa B Kinase; D011112:Polymyxin B