Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
41
pubmed:dateCreated
2004-10-6
pubmed:databankReference
pubmed:abstractText
Lung surfactant is the surface-active agent comprised of phospholipids and proteins that lines pulmonary alveoli. Surfactant stabilizes the alveolar volume by reducing surface tension. Previously, we identified a lysosomal phospholipase A2, termed LPLA2, with specificity toward phosphatidylcholine and phosphatidylethanolamine. The phospholipase is localized to lysosomes, is calcium-independent, has an acidic pH optimum, and transacylates ceramide. Here, we demonstrate that LPLA2 is selectively expressed in alveolar macrophages but not in peritoneal macrophages, peripheral blood monocytes, or other tissues. Other macrophage-associated phospholipase A2s do not show a comparable distribution. LPLA2 is of high specific activity and recognizes disaturated phosphatidylcholine as a substrate. The lysosomal phospholipase A2 activity is six times lower in alveolar macrophages from mice with a targeted deletion of the granulocyte macrophage colony-stimulating factor (GM-CSF), a model of impaired surfactant catabolism, compared with those from wild-type mice. However, LPLA2 activity and protein levels are measured in GM-CSF null mice in which GM-CSF is expressed as a transgene under the control of the surfactant protein C promoter. Thus LPLA2 may be a major enzyme of pulmonary surfactant phospholipid degradation by alveolar macrophages and may be deficient in disorders of surfactant metabolism.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
8
pubmed:volume
279
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
42605-11
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed-meshheading:15294901-1,2-Dipalmitoylphosphatidylcholine, pubmed-meshheading:15294901-Animals, pubmed-meshheading:15294901-COS Cells, pubmed-meshheading:15294901-DNA, Complementary, pubmed-meshheading:15294901-DNA Primers, pubmed-meshheading:15294901-Dose-Response Relationship, Drug, pubmed-meshheading:15294901-Female, pubmed-meshheading:15294901-Granulocyte-Macrophage Colony-Stimulating Factor, pubmed-meshheading:15294901-Hydrogen-Ion Concentration, pubmed-meshheading:15294901-Immunoblotting, pubmed-meshheading:15294901-Leukocytes, Mononuclear, pubmed-meshheading:15294901-Lysosomes, pubmed-meshheading:15294901-Macrophages, pubmed-meshheading:15294901-Macrophages, Alveolar, pubmed-meshheading:15294901-Macrophages, Peritoneal, pubmed-meshheading:15294901-Mice, pubmed-meshheading:15294901-Mice, Inbred C57BL, pubmed-meshheading:15294901-Mice, Transgenic, pubmed-meshheading:15294901-Molecular Sequence Data, pubmed-meshheading:15294901-Monocytes, pubmed-meshheading:15294901-Peptides, pubmed-meshheading:15294901-Phospholipases A, pubmed-meshheading:15294901-Phospholipases A2, pubmed-meshheading:15294901-Phospholipids, pubmed-meshheading:15294901-Plasmids, pubmed-meshheading:15294901-Promoter Regions, Genetic, pubmed-meshheading:15294901-RNA, pubmed-meshheading:15294901-RNA, Messenger, pubmed-meshheading:15294901-Rats, pubmed-meshheading:15294901-Rats, Wistar, pubmed-meshheading:15294901-Reverse Transcriptase Polymerase Chain Reaction, pubmed-meshheading:15294901-Time Factors, pubmed-meshheading:15294901-Tissue Distribution, pubmed-meshheading:15294901-Transgenes
pubmed:year
2004
pubmed:articleTitle
Lysosomal phospholipase A2 is selectively expressed in alveolar macrophages.
pubmed:affiliation
Division of Nephrology and Pulmonary and Critical Care Medicine, Department of Internal Medicine, University of Michigan Medical Center, Ann Arbor, Michigan 48109, USA.
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, Non-U.S. Gov't