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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2004-2-5
pubmed:abstractText
The transmembrane form of tumor necrosis factor (mTNF), expressed on activated monocytes (MO) and macrophages (MPhi), is able to induce apoptosis in human endothelial cells (EC). Apoptosis is mediated by two distinct mechanisms: direct cell contact and a yet-unidentified soluble protein, death factor X. In addition, mTNF acts as a receptor that transduces a "reverse signal" into MO/MPhi when bound to the TNF receptor on EC. Reverse signaling by mTNF confers resistance to bacterial lipopolysaccharide (LPS). Stimulation of reverse signaling by mTNF blocks the ability of MO/MPhi to produce death factor X and proinflammatory cytokines. We have investigated which signaling pathways are used by mTNF acting as receptor. Reverse signaling triggers two independent pathways that can be distinguished by protein kinase C (PKC) inhibitors. The suppression of LPS-induced death factor X is dependent on PKC, whereas the suppression of LPS-mediated cytokine release is not. LPS and reverse signaling stimulate the mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK) pathway. It is interesting that the activation of reverse signaling by mTNF renders MO/MPhi refractory to a subsequent activation of the MAPK/ERK pathway by LPS. Thus, reverse signaling achieves LPS resistance in monocytic cells through interference with key signal-transduction pathways.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0741-5400
pubmed:author
pubmed:issnType
Print
pubmed:volume
75
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
324-31
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed:year
2004
pubmed:articleTitle
LPS resistance in monocytic cells caused by reverse signaling through transmembrane TNF (mTNF) is mediated by the MAPK/ERK pathway.
pubmed:affiliation
Department of Hematology, University of Regensburg, Regensburg, Germany.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't