Crystal-induced neutrophil activation. II. Evidence for the activation of a phosphatidylcholine-specific phospholipase D

• Published in: Arthritis and rheumatism Vol. 36; no. 1; p. 117
• Main Authors: Naccache, P H, Bourgoin, S, Plante, E, Roberge, C J, de Medicis, R, Lussier, A, Poubelle, P E
• Format: Journal Article
• Language: English
• Published: United States 01-01-1993
• Subjects: Androstadienes - pharmacology; Calcium Pyrophosphate - pharmacology; Colchicine - pharmacology; Crystallization; Enzyme Activation; Ethanol - pharmacology; Glycerophospholipids; Humans; Hydrolysis; Neutrophils - drug effects; Neutrophils - metabolism; Pertussis Toxin; Phosphatidic Acids - metabolism; Phosphatidylcholines - metabolism; Phospholipase D - antagonists & inhibitors; Phospholipase D - metabolism; Superoxides - metabolism; Uric Acid - pharmacology; Virulence Factors, Bordetella - pharmacology; Wortmannin
• ISSN: 0004-3591
• DOI: 10.1002/art.1780360119

To investigate the involvement of phospholipase D in the signaling pathways activated by 2 pathologically relevant inflammatory microcrystals, monosodium urate (MSU) and calcium pyrophosphate dihydrate (CPPD).
Human peripheral blood neutrophils were used throughout. Phospholipase D activity was monitored by measuring 3 separate indices: 1) the mass of phosphatidic acid, 2) the levels of alkyl-phosphatidic acid, and 3) the levels of formation, in the presence of ethanol, of phosphatidylethanol. The latter 2 parameters were measured in cells labeled with 1-0-3H-alkyl-2-acetyl-sn-glycero-3-phosphocholine. The cells were stimulated with microcrystals of triclinic morphology.
Both MSU and CPPD crystals induced a time- and concentration-dependent accumulation of phosphatidic acid mass and elevation in levels of alkyl-phosphatidic acid and phosphatidylethanol in prelabeled cells. The activation of phospholipase D by the microcrystals was partially sensitive to colchicine and largely resistant to pertussis toxin. Inhibition of phosphatidic acid formation by wortmannin or ethanol reduced the microcrystal-stimulated production of superoxide anions.
These results indicate that microcrystals stimulate phospholipase D in human neutrophils and that at least some of the functional consequences of neutrophil-microcrystal interactions may be dependent on this biochemical pathway.