Linked Life Data

9574558

Source:http://linkedlifedata.com/resource/pubmed/id/9574558

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
9
pubmed:dateCreated
1998-5-21
pubmed:abstractText
TNF-alpha is implicated in the initiation of cytokine cascades in various inflammatory settings. To assess the interactions of multiple cytokines at the level of inflammatory effector cells, we examined the effects of TNF-alpha on the expression of two IL-8Rs (CXCR1 and CXCR2) on polymorphonuclear leukocytes (PMNs). TNF-alpha decreased the surface expression of CXCR2 in a dose- and time-dependent manner. In contrast, CXCR1 expression was not affected by TNF-alpha. The release of CXCR2 into the supernatant of TNF-alpha-treated PMNs was detected by immunoblotting and immuno-slot-blot analyses, suggesting that the down-regulation of CXCR2 was caused mainly by shedding from the cell surface. The CXCR2 down-regulation was inhibited by PMSF and aprotinin, supporting the hypothesis that the shedding was mediated by serine protease(s). The intracellular Ca2+ mobilization and chemotaxis in response to IL-8 were suppressed by the pretreatment of PMNs with TNF-alpha, indicating that the decrease in CXCR2 was reflected in the decreased functional responses to IL-8. In contrast, the O2- release, which is mediated by CXCR1, was not suppressed by TNF-alpha. The treatment of whole blood with TNF-alpha also caused a significant reduction in CXCR2 and markedly suppressed intracellular Ca2+ mobilization and chemotaxis in response to IL-8, while enhancing the O2- release. These findings suggest that TNF-alpha down-regulates CXCR2 expression on PMNs and modulates IL-8-induced biologic responses, leading to the intravascular retention of PMNs with an enhanced production of reactive oxygen metabolites.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0022-1767
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
160
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
4518-25
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1998
pubmed:articleTitle
Down-regulation of CXCR2 expression on human polymorphonuclear leukocytes by TNF-alpha.
pubmed:affiliation
Department of Hematology and Oncology, Graduate School of Medicine, Kyoto University, Japan.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't