Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
7
pubmed:dateCreated
2005-3-21
pubmed:abstractText
The p38 MAPK signal transduction pathway is a key regulator of IL-1 and TNF-alpha production in rheumatoid arthritis. Previous studies demonstrated that upstream MAPK kinases (MKK3 and MKK6) that regulate p38 are activated in rheumatoid arthritis synovium. However, their functional relevance in fibroblast-like synoviocytes (FLS) has not been determined. To investigate the relative contribution of MKK3 and MKK6 to p38 activation, the effect of dominant-negative (DN) MKK3 and MKK6 constructs on cultured FLS was evaluated. Cultured FLS were stimulated with medium or IL-1beta, and immunoblotting was performed. In some experiments, cells were lysed and immunoprecipitated with anti-p38 Ab, followed by in vitro kinase assay with [gamma-(32)P]ATP and GST-activating transcription factor-2 as substrate. IL-1beta rapidly induced p38 phosphorylation in cells transfected with empty vector (pcDNA3.1), but was inhibited by 25% in cells expressing DN MKK3 or DN MKK6. Cotransfection with both DN plasmids decreased phospho-p38 by almost 75%. In vitro kinase assays on IL-1-stimulated FLS also showed that the combination of DN MKK3 and DN MKK6 markedly decreased kinase activity compared with empty vector or the individual DN plasmids. Furthermore, IL-1beta-induced IL-8, IL-6, and matrix metalloproteinase-3 protein production was significantly inhibited in DN MKK3/DN MKK6-transfected cells. The constructs had no effect on the respective mediator mRNA levels. These data demonstrate that MKK3 and MKK6 make individual contributions to p38 activation in FLS after cytokine stimulation, but that both must be blocked for maximum inhibition.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0022-1767
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
174
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
4301-6
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed:year
2005
pubmed:articleTitle
Regulation of p38 MAPK by MAPK kinases 3 and 6 in fibroblast-like synoviocytes.
pubmed:affiliation
Division of Rheumatology, Allergy, and Immunology, University of California, San Diego, School of Medicine, La Jolla, CA 92093-0656, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.