The goal of the current study was to determine whether the binding of secretory phospholipase A2 (sPLA2) to cell surface receptors is important in arachidonic acid (AA) mobilization by murine bone marrow derived mast cells (BMMC). M-type sPLA2 receptor cDNA was subcloned into a mammalian expression vector (pCMV-5/PLA2R™) and then utilized to transfect BMMC. Western blot analysis indicated increased expression of a 180 kDa protein within 6-12 h after transfection of BMMC. Maximum expression of the 180 kDa sPLA2 receptor was observed at 24 h followed by a decrease in levels by 48-72 h. Stimulation of BMMC with antigen resulted in an eight-fold increase in AA release from pCMV-5/PLA2R™ transfected cells compared to the mock-transfected controls. Maximum AA mobilization from BMMC occurred 48 h after transfection. These initial studies suggested that sPLA2 released by antigen-stimulated mast cells induces AA release via its capacity to bind to cell surface receptors. In another set of studies, BMMC were incubated with different concentrations of sPLA2. Cells expressing M-type SPLA2 receptor released more AA (∼2 fold) than mock-transfected cells. Taken together, these data suggest that PLA2 secreted by stimulated BMMC or provided from exogenous sources mediates AA release from mast cells by binding to cell surface receptors.
|Original language||English (US)|
|State||Published - Mar 20 1998|
ASJC Scopus subject areas
- Molecular Biology