[Lipopolysaccharide enhances DNA binding activity of nuclear factor-kappa B in the mouse cochlea].
OBJECTIVE
To ascertain whether inoculation of lipopolysaccharide (LPS) into the mouse cochlea might induce enhancement of DNA binding activity of NK-kappa B and to establish a positive model of NF-kappa B activation in the cochlea.


METHODS
Two groups of CBA mice were transtympanically injected either with 10 micrograms of LPS or an equal volume of saline. The nuclear proteins of the cochlea were extracted, quantitated and bound with 32P-radiolabeled oligonucleotide probe for NF-kappa B. The bound and free probes were separated by electrophoresis on a 4.5% native polyacrylamide gel. Supershift assays were carried out using the antibodies against NF-kappa B subunit P65 and P50.


RESULTS
The radiolabeled probe bound differently to nuclear extracts from the LPS-treated and the saline-treated mouse cochleae, showing that LPS inoculation significantly increased NF-kappa B binding activity. Supershift analysis demonstrated that the enhancement of DNA binding activity was related to both P65 and P50 subunits.


CONCLUSIONS
LPS could induce NF-kappa B activation in the cochlea. Moreover, this study implies that tissues from LPS-inoculated cochlea might serve as a useful positive control in the study on activation of NF-kappa B in cochlea.
Wu
Weijng
W
Department of Otorhinolaryngology, Second Hospital of Xiangya Medical School, University of Central-Southern China, Changsha 410011, China. weijwu@163.com
Xie
Dinghua
D
D000818:Animals; D003051:Cochlea / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000187:drug effects / Q000378:metabolism*; D008070:Lipopolysaccharides / Q000494:pharmacology*; D008297:Male; D051379:Mice; D008808:Mice, Inbred CBA; D016328:NF-kappa B / Q000187:drug effects / Q000378:metabolism*
D004268:DNA-Binding Proteins; D008070:Lipopolysaccharides; D016328:NF-kappa B