Pancreatic-type phospholipase A2 induces group II phospholipase A2 expression and prostaglandin biosynthesis in rat mesangial cells

• Published in: The Journal of biological chemistry Vol. 269; no. 7; pp. 5092 - 5098
• Main Authors: KISHINO, J, OHARA, O, NOMURA, K, KRAMER, R. M, ARITA, H
• Format: Journal Article
• Language: English
• Published: Bethesda, MD American Society for Biochemistry and Molecular Biology 18.02.1994
• Subjects: Analytical, structural and metabolic biochemistry; Animals; Bee Venoms - pharmacology; Binding Sites; Binding, Competitive; Biological and medical sciences; Cells, Cultured; Cytosol - enzymology; Dinoprostone - biosynthesis; Elapid Venoms - pharmacology; Enzymes and enzyme inhibitors; Fundamental and applied biological sciences. Psychology; Gene Expression; Glomerular Mesangium - enzymology; Glomerular Mesangium - metabolism; Hydrolases; Immunoblotting; Isoenzymes - biosynthesis; Isoenzymes - metabolism; Isoenzymes - pharmacology; Kinetics; Male; Pancreas - enzymology; Phospholipases A - biosynthesis; Phospholipases A - metabolism; Phospholipases A - pharmacology; Phospholipases A2; Prostaglandin-Endoperoxide Synthases - metabolism; Rats; Rats, Wistar; Swine; Rat; Enzyme; Mesangial cell; Isozyme; Rodentia; Prostaglandin E2; Tissue specificity; Esterases; Binding site; Gene expression; Phospholipase A; Carboxylic ester hydrolases; Vertebrata; Mammalia; Hydrolases
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1016/S0021-9258(17)37659-7

The effect of pancreatic group I phospholipase A2 (PLA2-I) on receptor-mediated expression of arthritic group II phospholipase A2 (PLA2-II) and its correlation with prostaglandin E2 (PGE2) synthesis were examined in cultured rat mesangial cells. Scatchard analysis using 125I-PLA2-I revealed the existence of a single class of specific binding sites for PLA2-I in rat mesangial cells with an equilibrium dissociation constant (Kd) of 1.6 nM and a maximum binding capacity of 10.1 fmol/10(6) cells. The mammalian mature type of PLA2-I specifically recognized this binding site, whereas its inactive zymogen and mammalian PLA2-II showed much lower affinities. PLA2-I markedly increased PLA2-II mRNA levels as well as PLA2-II secretion from the cells in a time- and dose-dependent manner that was closely correlated with PGE2 production. Both PLA2-II expression and PGE2 synthesis were completely suppressed by pretreatment of the cells with actinomycin D, cycloheximide, or dexamethasone. These results strongly suggest that there may be crosstalk between PLA2-I and PLA2-II via the specific PLA2-I receptor that elicits PGE2 synthesis.