Secretory phospholipase A2 generates the novel lipid mediator lysophosphatidic acid in membrane microvesicles shed from activated cells.
Cell
; 80(6): 919-27, 1995 Mar 24.
Article
en En
| MEDLINE
| ID: mdl-7697722
ABSTRACT
Nonpancreatic secretory phospholipase A2 (sPLA2) displays proinflammatory properties; however, its physiological substrate is not identified. Although inactive toward intact cells, sPLA2 hydrolyzed phospholipids in membrane microvesicles shed from Ca(2+)-loaded erythrocytes as well as from platelets and from whole blood cells challenged with inflammatory stimuli. sPLA2 was stimulated upon degradation of sphingomyelin (SPH) and produced lysophosphatidic acid (LPA), which induced platelet aggregation. Finally, lysophospholipid-containing vesicles and sPLA2 were detected in inflammatory fluids in relative proportions identical to those used in vitro. We conclude that upon loss of phospholipid asymmetry, cell-derived microvesicles provide a preferential substrate for sPLA2. SPH hydrolysis, which is provoked by various cytokines, regulates sPLA2 activity, and the novel lipid mediator LPA can be generated by this pathway.
Buscar en Google
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Fosfolipasas A
/
Lisofosfolípidos
/
Lípidos de la Membrana
Límite:
Animals
/
Humans
Idioma:
En
Revista:
Cell
Año:
1995
Tipo del documento:
Article
País de afiliación:
Francia