Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
2007-5-17
pubmed:abstractText
Wild-type (WT) Salmonella typhimurium causes acute intestinal inflammation by activating the nuclear factor kappa B (NF-kappaB) pathway. Interestingly, WT Salmonella infection also causes degradation of beta-catenin, a regulator of cellular proliferation. Regulation of beta-catenin and the inhibitor of NF-kappaB, IkappaBalpha, is strikingly similar, involving phosphorylation at identical sites, ubiquitination by the same E3 ligase, and subsequent proteasomal degradation. However, how beta-catenin directly regulates the NF-kappaB pathway during bacteria-induced inflammation in vivo is unknown. Using streptomycin-pretreated mice challenged with Salmonella, we demonstrated that WT Salmonella stimulated beta-catenin degradation and decreased the physical association between NF-kappaB and beta-catenin. Accordingly, WT Salmonella infection decreased the expression of c-myc, a beta-catenin-regulated target gene, and increased the levels of IL-6 and TNF-alpha, the NF-kappaB-regulated target genes. Bacterial infection directly stimulated phosphorylation of beta-catenin, both in vivo and in vitro. Closer examination revealed that glycogen synthase kinase 3beta (GSK-3beta) kinase activity was increased in response to WT Salmonella, whereas non-virulent Salmonella had no effect. siRNA of GSK-3beta was able to stabilize IkappaBalpha in response to WT Salmonella. Pretreatment for 24 h with LiCl, an inhibitor of GSK-3beta, reduced WT Salmonella induced IL-8 secretion. Additionally, cells expressing constitutively active beta-catenin showed IkappaBalpha stabilization and inhibition of NF-kappaB activity not only after WT Salmonella infection but also after commensal bacteria (Escherichia coli F18) and TNF-alpha treatment. This study suggests a new role for beta-catenin as a negative regulator of inflammation.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0023-6837
pubmed:author
pubmed:issnType
Print
pubmed:volume
87
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
613-24
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed:year
2007
pubmed:articleTitle
beta-Catenin activity negatively regulates bacteria-induced inflammation.
pubmed:affiliation
Department of Pathology, The University of Chicago, Chicago, IL 60637, USA.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't, Research Support, N.I.H., Extramural