Source:http://linkedlifedata.com/resource/pubmed/id/16081790
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| Predicate | Object |
|---|---|
| rdf:type | |
| lifeskim:mentions | |
| pubmed:issue |
4
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| pubmed:dateCreated |
2005-8-5
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| pubmed:abstractText |
Surfactant protein A (SP-A), a major component of lung surfactant, binds to macrophages and has been shown to alter several macrophage biological functions, including up-regulation of macrophage mannose receptor (MR) activity. In the present study, we show that SP-A induces signal transduction pathway(s) that impact on MR expression. The addition of human, rat, or recombinant rat SP-A to human monocyte-derived macrophages significantly raised the level of cytosolic Ca2+ above baseline within 10 s of SP-A addition, as measured by spectrofluorometric analysis. SP-A induced a refractory state specific for SP-A consistent with homologous desensitization of a receptor(s) linked to calcium mobilization because a second application of SP-A did not induce a rise in cytosolic Ca2+ whereas the addition of platelet-activating factor did. Using site-directed mutations in SP-A, we determined that both the attached sugars and the collagen-like domain of SP-A are necessary to optimize Ca2+ mobilization. SP-A triggered the increase in cytosolic Ca2+ by inducing activation of phospholipase C, which leads to the hydrolysis of membrane phospholipids, yielding inositol 1,4,5-trisphosphate and mobilizing intracellularly stored Ca2+ by inositol triphosphate-sensitive channels. Finally, inhibition of PI3Ks, which appear to act upstream of phospholipase C in Ca2+ mobilization, decreased the SP-A-induced rise in MR expression, providing evidence that SP-A induction of MR activity involves the activation of a pathway in which PI3K is a component. These studies provide further evidence that SP-A produced in the lung plays a role in modulating macrophage biology, thereby contributing to the alternative activation state of the alveolar macrophage.
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| pubmed:grant | |
| pubmed:language |
eng
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| pubmed:journal | |
| pubmed:citationSubset |
AIM
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| pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/Calcium,
http://linkedlifedata.com/resource/pubmed/chemical/Collagen,
http://linkedlifedata.com/resource/pubmed/chemical/Inositol 1,4,5-Trisphosphate,
http://linkedlifedata.com/resource/pubmed/chemical/Lectins, C-Type,
http://linkedlifedata.com/resource/pubmed/chemical/Lipopolysaccharides,
http://linkedlifedata.com/resource/pubmed/chemical/Mannose-Binding Lectins,
http://linkedlifedata.com/resource/pubmed/chemical/Oligosaccharides,
http://linkedlifedata.com/resource/pubmed/chemical/Phosphatidylinositol 3-Kinases,
http://linkedlifedata.com/resource/pubmed/chemical/Pulmonary Surfactant-Associated...,
http://linkedlifedata.com/resource/pubmed/chemical/Receptors, Cell Surface,
http://linkedlifedata.com/resource/pubmed/chemical/mannose receptor
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| pubmed:status |
MEDLINE
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| pubmed:month |
Aug
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| pubmed:issn |
0022-1767
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| pubmed:author | |
| pubmed:issnType |
Print
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| pubmed:day |
15
|
| pubmed:volume |
175
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| pubmed:owner |
NLM
|
| pubmed:authorsComplete |
Y
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| pubmed:pagination |
2227-36
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| pubmed:dateRevised |
2010-11-18
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| pubmed:meshHeading |
pubmed-meshheading:16081790-Adult,
pubmed-meshheading:16081790-Animals,
pubmed-meshheading:16081790-Binding Sites,
pubmed-meshheading:16081790-Calcium,
pubmed-meshheading:16081790-Calcium Signaling,
pubmed-meshheading:16081790-Collagen,
pubmed-meshheading:16081790-Cytosol,
pubmed-meshheading:16081790-Dose-Response Relationship, Immunologic,
pubmed-meshheading:16081790-Humans,
pubmed-meshheading:16081790-Inositol 1,4,5-Trisphosphate,
pubmed-meshheading:16081790-Intracellular Fluid,
pubmed-meshheading:16081790-Lectins, C-Type,
pubmed-meshheading:16081790-Lipopolysaccharides,
pubmed-meshheading:16081790-Macrophage Activation,
pubmed-meshheading:16081790-Macrophages,
pubmed-meshheading:16081790-Mannose-Binding Lectins,
pubmed-meshheading:16081790-Monocytes,
pubmed-meshheading:16081790-Oligosaccharides,
pubmed-meshheading:16081790-Phosphatidylinositol 3-Kinases,
pubmed-meshheading:16081790-Protein Structure, Tertiary,
pubmed-meshheading:16081790-Pulmonary Surfactant-Associated Protein A,
pubmed-meshheading:16081790-Rats,
pubmed-meshheading:16081790-Receptors, Cell Surface,
pubmed-meshheading:16081790-U937 Cells,
pubmed-meshheading:16081790-Up-Regulation
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| pubmed:year |
2005
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| pubmed:articleTitle |
Pulmonary surfactant protein A activates a phosphatidylinositol 3-kinase/calcium signal transduction pathway in human macrophages: participation in the up-regulation of mannose receptor activity.
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| pubmed:affiliation |
Interdisciplinary Program in Immunology and Department of Internal Medicine, University of Iowa, Iowa City, IA 52240, USA.
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| pubmed:publicationType |
Journal Article,
Research Support, U.S. Gov't, P.H.S.,
Research Support, U.S. Gov't, Non-P.H.S.,
Research Support, N.I.H., Extramural
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