Linked Life Data

16840786

Source:http://linkedlifedata.com/resource/pubmed/id/16840786

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
36
pubmed:dateCreated
2006-9-4
pubmed:abstractText
Little is known about the pathogenesis of Entamoeba histolytica and how epithelial cells respond to the parasite. Herein, we characterized the interactions between E. histolytica and colonic epithelial cells and the role macrophages play in modulating epithelial cell responses. The human colonic epithelial cell lines Caco-2 and T84 were grown either as monoculture or co-cultured in transwell plates with differentiated human THP-1 macrophages for 24 h before stimulation with soluble amebic proteins (SAP). In naive epithelial cells, prolonged stimulation with SAP reduced the levels of heat shock protein (Hsp) 27 and 72. However in THP-1 conditioned intestinal epithelial cells SAP enhanced Hsp27 and Hsp72, which was dependent on the activation of ERK MAP kinase. Hsp synthesis induced by SAP conferred protection against oxidative and apoptotic injuries. Treatment with SAP inhibited NF-kappaB activation induced by interleukin-1beta; specifically, the NF-kappaB-DNA binding, nuclear translocation of p65 subunit, and phosphorylation of IkappaB-alpha were reduced. Gene silencing by small interfering RNA confirmed the role of Hsp27 in suppressing NF-kappaB activation at IkappaB kinase (IKK) level. By co-immunoprecipitation studies, we found that Hsp27 interacts with IKK-alpha and IKK-beta, and this association was increased in SAP-treated conditioned epithelial cells. Overexpression of wild type Hsp27 amplified the effects of SAP, whereas a phosphorylation-deficient mutant of Hsp27 abrogated SAP-induced NF-kappaB inhibition. In conditioned epithelial cells, Hsp27 was phosphorylated at serine 15 after prolonged exposure to SAP. This mechanism may explain the absence of colonic inflammation seen in the majority of individuals infected with E. histolytica.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
8
pubmed:volume
281
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
26112-20
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed-meshheading:16840786-Animals, pubmed-meshheading:16840786-Cell Line, pubmed-meshheading:16840786-Coculture Techniques, pubmed-meshheading:16840786-Colitis, pubmed-meshheading:16840786-Colon, pubmed-meshheading:16840786-Cysteine Endopeptidases, pubmed-meshheading:16840786-Entamoeba histolytica, pubmed-meshheading:16840786-Epithelial Cells, pubmed-meshheading:16840786-Extracellular Signal-Regulated MAP Kinases, pubmed-meshheading:16840786-Galectins, pubmed-meshheading:16840786-Heat-Shock Proteins, pubmed-meshheading:16840786-Humans, pubmed-meshheading:16840786-I-kappa B Kinase, pubmed-meshheading:16840786-Interleukin-1beta, pubmed-meshheading:16840786-Intestinal Mucosa, pubmed-meshheading:16840786-Macrophages, pubmed-meshheading:16840786-Models, Biological, pubmed-meshheading:16840786-NF-kappa B, pubmed-meshheading:16840786-Protozoan Proteins, pubmed-meshheading:16840786-RNA, Small Interfering
pubmed:year
2006
pubmed:articleTitle
Suppression of NF-kappaB activation by Entamoeba histolytica in intestinal epithelial cells is mediated by heat shock protein 27.
pubmed:affiliation
Department of Microbiology and Infectious Diseases, University of Calgary, Calgary, Alberta T2N 4N1, Canada.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't