Linked Life Data

9973428

Source:http://linkedlifedata.com/resource/pubmed/id/9973428

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1999-4-13
pubmed:abstractText
The enzyme 5-lipoxygenase (5-LO) catalyzes the synthesis of leukotrienes (LTs) from arachidonic acid (AA). Adherence or recruitment of polymorphonuclear neutrophils (PMN) induces nuclear import of 5-LO from the cytosol, which is associated with enhanced LTB4 synthesis upon subsequent cell stimulation. In this study, we asked whether adherence of human eosinophils (EOS) causes a similar redistribution of 5-LO and an increase in LTC4 synthesis. Purified blood EOS examined either in suspension or after adherence to fibronectin for 5 min contained only cytosolic 5-LO. Cell stimulation resulted in activation of 5-LO, as evidenced by its translocation to membranes and LTC4 synthesis. As with PMN, adherence of EOS to fibronectin for 120 min caused nuclear import of 5-LO. Unexpectedly, however, adherence also caused a time-dependent decrease in LTC4 synthesis: EOS adhered for 120 min produced 90% less LTC4 than did cells adhered for 5 min. Adherence did not diminish the release of [3H]AA from prelabeled EOS or reduce the synthesis of the prostanoids thromboxane and PGE2. Also, inhibition of LTC4 production caused by adherence could not be overcome by the addition of exogenous AA. Adherence increased, rather than decreased, LTC4 synthase activity. However, the stimulation of adherent EOS failed to induce translocation of 5-LO from the nucleoplasm to the nuclear envelope. This resistance to activation of the nuclear pool of 5-LO with diminished LT production represents a novel mode of regulation of the enzyme, distinct from the paradigm of up-regulated LT synthesis associated with intranuclear localization of 5-LO observed in PMN and other cell types.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0022-1767
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
162
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1669-76
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1999
pubmed:articleTitle
Decreased leukotriene C4 synthesis accompanies adherence-dependent nuclear import of 5-lipoxygenase in human blood eosinophils.
pubmed:affiliation
Division of Pulmonary and Critical Care Medicine, University of Michigan Medical Center, Ann Arbor, MI 48109, USA. brocko@medmail.med.umich.edu
pubmed:publicationType
Journal Article, In Vitro, Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't