Torrie, L.J. and MacKenzie, C. and Paul, A. and Plevin, R.J. (2001) Hydrogen peroxide-mediated inhibition of lipopolysaccharide-stimulated inhibitory kappa b kinase activity in rat aortic smooth muscle cells. British Journal of Pharmacology, 134 (2). pp. 393-401. ISSN 0007-1188Full text not available in this repository. (Request a copy from the Strathclyde author)
In rat aortic smooth muscle cells (RASMC), exposure to lipopolysaccharide (LPS) resulted in NF-κB-DNA binding, degradation of IκB-α, -β and -ε and increased activity of both α and β isoforms of inhibitory kappa B kinase (IKK). Expression of dominant-negative (DN)-IKK-α, IKK-β and NF-κB-inducing kinase (NIK) abolished LPS-stimulated NF-κB reporter activity, suggesting that activation of a NIK/IKK-dependent pathway is indispensable for NF-κB activation by LPS in this cell type. The tyrosine phosphatase inhibitor, pervanadate, abolished LPS-stimulated NF-κB-DNA-binding activity. However, the effect of pervanadate was shown to be mediated by excess hydrogen peroxide (H2O2) present in the reaction mix. Preincubation of RASMC with H2O2 inhibited LPS-stimulated IKK kinase activity and downstream NF-κB-DNA binding activity. H2O2 also strongly stimulated p38 MAP kinase activity in RASMCs. Effective inhibition of this pathway using SB203580 did not reverse the effects of H2O2 on LPS-stimulated IKK/NF-κB signalling. These studies show that hydrogen peroxide-mediated inhibition of LPS-stimulated NF-κB activation in RASMC occurs upstream of IKK. The inhibitory effect of H2O2 is not due to tyrosine phosphatase inhibition, it is mediated by H2O2 through a mechanism which is independent of any cross-talk involving MAP kinase homologues.
|Keywords:||hydrogen peroxide, rat aortic smooth muscle cells , lipopolysaccharide, inhibitory kappa B kinase , Pharmacy and materia medica, Pharmacology|
|Subjects:||Medicine > Pharmacy and materia medica|
|Department:||Faculty of Science > Strathclyde Institute of Pharmacy and Biomedical Sciences|
|Depositing user:||Pure Administrator|
|Date Deposited:||02 Apr 2012 13:03|
|Last modified:||06 Jan 2017 06:18|