Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0043167 (pertussis)
 19,595 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In the present paper, the effect of sphingosine 1-phosphate (Sph-1-P) on arachidonic acid mobilization in A549 human lung adenocarcinoma cells was investigated. Sph-1-P provoked a rapid and relevant release of arachidonic acid which was similar to that elicited by bradykinin, well-known pro-inflammatory agonist. The Sph-1-P-induced release of arachidonic acid involved Ca(2+)-independent phospholipase A(2) (iPLA2) activity, as suggested by the dose-dependent inhibition exerted by the rather specific inhibitor bromoenol lactone. The Sph-1-P-induced release of arachidonic acid was pertussis toxin-sensitive, pointing at a receptor-mediated mechanism, which involves heterotrimeric Gi proteins. The action of Sph-1-P was totally dependent on protein kinase C (PKC) catalytic activity and seemed to involve agonist-stimulated phospholipase D (PLD) activity. This study represents the first evidence for Sph-1-P-induced release of arachidonic acid which occurs through a specific signaling pathway involving Gi protein-coupled receptor(s), PKC, PLD and iPLA2 activities.
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PMID:Sphingosine 1-phosphate induces arachidonic acid mobilization in A549 human lung adenocarcinoma cells. 1060 4

Treatment of bovine pulmonary artery endothelial cells with the calcium ionophore, A23187, stimulates the cell membrane associated protease activity, phospholipase A2 (PLA2) activity, and arachidonic acid (AA) release from the cells. Pretreatment of the cells with arachidonyl-trifluomethylketone (AACOCF3), a cPLA2 inhibitor, but not bromoenollactone (BEL), a iPLA2 inhibitor, prevents A23187 stimulated PLA2 activity and AA release without producing an appreciable alteration of the protease activity. Pretreatment of the cells with aprotinin, an ambient protease inhibitor, prevents the increase in the protease activity and cPLA2 activity in the membrane and AA release from the cells caused by both low and high doses of A23187, and also inhibits protein kinase C (PKC) activity caused by high doses of A23187. Immunoblot study of the endothelial cell membrane isolated from A23187 (10 microM)-treated cells with polyclonal PKCalpha antibody elicited an increase in the 80 kDa immunoreactive protein band along with an additional 47 kDa immunoreactive fragment. Pretreatment of the cells with aprotinin abolished the 47 kDa immunoreactive fragment in the immunoblot. Immunoblot study of the endothelial membrane with polyclonal cPLA2 antibody revealed that treatment of the cells with A23187 dose-dependently increases cPLA2 immunoreactive protein profile in the membrane. It therefore appears from the present study that treatment of the cells with a low dose of A23187 (1 microM) causes a small increase in an aprotinin-sensitive protease activity and that stimulates cPLA2 activity in the cell membrane without an involvement of PKC. By contrast, treatment of the cells with a high dose of 10 microM of A23187 causes optimum increase in the protease activity and that plays an important role in activating PKCalpha, which subsequently stimulates cPLA2 activity in the cell membrane. Although pretreatment of the cells with pertussis toxin caused ADP ribosylation of a 41 kDa protein in the cell membrane, it did not inhibit the cPLA2 activity and AA release caused by both low and high doses of A23187.
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PMID:Role of an aprotinin-sensitive protease in protein kinase Calpha-mediated activation of cytosolic phospholipase A2 by calcium ionophore (A23187) in pulmonary endothelium. 1509 16