ICAM-1 expression is highly NF-kappaB-dependent in A549 cells. No role for ERK and p38 MAPK.
The transcription factor nuclear factor kappaB (NF-kappaB) is an activator of multiple cytokines, chemokines and adhesion molecules, which are important in inflammatory diseases such as asthma, and is consequently considered as an attractive therapeutic target. In the present study, a constitutively active dominant version of IkappaBalpha, IkappaBalphaDN, was introduced into A549 pulmonary cells by adenovirus-mediated delivery. The dominant IkappaB, but not a null viral vector, prevented the induction of NF-kappaB-dependent transcription by both tumor necrosis factor alpha (TNFalpha) and interleukin-1beta (IL-1beta). Similarly, both TNFalpha and IL-1beta strongly induced mRNA and protein expression of intercellular adhesion molecule (ICAM)-1 and in each case this was prevented by adenovirus expressing the dominant IkappaB, but not by the null virus, thereby establishing ICAM-1 as an NF-kappaB-dependent gene. Numerous studies have suggested key roles for the p38 and extracellular regulated kinase (ERK) mitogen-activated protein kinase (MAPK) cascades in the activation and transactivation of NF-kappaB. We show here that SB203580, a selective inhibitor of the p38 MAPK, and PD098059 and UO126, both selective inhibitors of the ERK MAPK cascade, have no effect on TNFalpha or IL-1beta-induced translocation and DNA binding of NF-kappaB. Furthermore, these inhibitors showed no pharmacologically relevant effect on NF-kappaB-dependent transcription nor was there any effect on expression of ICAM-1. Taken together these data highlight the potential use of inhibition of the NF-kappaB signalling pathway in pulmonary inflammatory diseases and suggest that inhibitors of the p38 and ERK MAPK pathways may be of lesser effect.
Holden
Neil S
NS
Department of Biological Sciences, University of Warwick, Coventry, UK.
Catley
Matthew C
MC
Cambridge
Lisa M
LM
Barnes
Peter J
PJ
Newton
Robert
R
D000256:Adenoviridae / Q000235:genetics; D045744:Cell Line, Tumor; D004247:DNA / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006801:Humans; D020672:I-kappa B Proteins / Q000378:metabolism; D018799:Intercellular Adhesion Molecule-1 / Q000096:biosynthesis* / Q000235:genetics; D007375:Interleukin-1 / Q000494:pharmacology; D008156:Luciferases / Q000378:metabolism; D020928:Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D016328:NF-kappa B / Q000378:metabolism*; D011485:Protein Binding; D014158:Transcription, Genetic; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology; D048051:p38 Mitogen-Activated Protein Kinases
D004791:Enzyme Inhibitors; D020672:I-kappa B Proteins; D007375:Interleukin-1; D016328:NF-kappa B; D014409:Tumor Necrosis Factor-alpha; D018799:Intercellular Adhesion Molecule-1; D004247:DNA; D008156:Luciferases; D020928:Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases