Premium
Cytosolic phospholipase A 2 is responsible for prostaglandin E 2 and leukotriene B 4 formation in phagocyte‐like PLB‐985 cells: studies of differentiated cPLA 2 ‐deficient PLB‐985 cells
Author(s) -
Liberty I. Furstenberg,
Raichel L.,
HazanEitan Z.,
Pessach I.,
Hadad N.,
Schlaeffer F.,
Levy R.
Publication year - 2004
Publication title -
journal of leukocyte biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.819
H-Index - 191
eISSN - 1938-3673
pISSN - 0741-5400
DOI - 10.1189/jlb.1003453
Subject(s) - ionomycin , monocyte , granulocyte , phospholipase a2 , biology , zymosan , medicine , phorbol , endocrinology , microbiology and biotechnology , immunology , stimulation , biochemistry , protein kinase c , signal transduction , enzyme , in vitro
Our previously established model of cytosolic phospholipase A 2 (cPLA 2 )‐deficient, differentiated PLB‐985 cells (PLB‐D cells) was used to determine the physiological role of cPLA 2 in eicosanoid production. Parent PLB‐985 (PLB) cells and PLB‐D cells were differentiated toward the monocyte or granulocyte lineages using 5 × 10 − 8 M 1,25 dihydroxyvitamin D 3 or 1.25% dimethyl sulfoxide, respectively. Parent monocyte‐ or granulocyte‐like PLB cells released prostaglandin E 2 (PGE 2 ) when stimulated by ionomycin, A23187, opsonized zymosan, phorbol 12‐myristate 13‐acetate, or formyl‐Met‐Leu‐Phe (fMLP), and monocyte‐ or granulocyte‐like PLB‐D cells did not release PGE 2 with any of the agonists. The kinetics of cPLA 2 translocation to nuclear fractions in monocyte‐like PLB cells stimulated with fMLP or ionomycin was in correlation with the kinetics of PGE 2 production. Granulocyte‐like PLB cells, but not granulocyte‐like PLB‐D cells, secreted leukotriene B 4 (LTB 4 ) after stimulation with ionomycin or A23187. Preincubation of monocyte‐like parent PLB cells with 100 ng/ml lipopolysaccharide (LPS) for 16 h enhanced stimulated PGE 2 production, which is in correlation with the increased levels of cPLA 2 detected in these cells. LPS preincubation was less potent in increasing PGE 2 and LTB 4 secretion and did not affect cPLA 2 expression in granulocyte‐like PLB cells, which may be a result of their lower levels of surface LPS receptor expression. LPS had no effect on monocyte‐ or granulocyte‐like PLB‐D cells. The lack of eicosanoid formation in stimulated, differentiated cPLA 2 ‐deficient PLB cells indicates that cPLA 2 contributes to stimulated eicosanoid formation in monocyte‐ and granulocyte‐like PLB cells.