Interleukin-1 activates phospholipase A2 in human synovial cells.
Interleukin-1 (IL-1) treatment of synovial cells from rheumatoid arthritis and osteoarthritis patients resulted in a dose-dependent secretion of phospholipase A2 (PLA2). IL-1 also stimulated prostaglandin E2 and plasminogen activator synthesis, in parallel with PLA2 activation; all 3 were detectable within 6 hours of IL-1 treatment and peaked by 24 hours. Synovial cell PLA2 required calcium (5 mM) and a neutral pH (7.5) for maximal activity and appears similar to the PLA2 in synovial fluid, which has been described previously. We conclude that PLA2 can be induced by IL-1, and its secretion may contribute significantly to the inflammatory actions of IL-1.
Gilman
S C
SC
Division of Experimental Therapeutics, Wyeth Laboratories, Philadelphia, PA 19101.
Chang
J
J
Zeigler
P R
PR
Uhl
J
J
Mochan
E
E
D001172:Arthritis, Rheumatoid / Q000201:enzymology / Q000378:metabolism / Q000473:pathology; D002118:Calcium / Q000494:pharmacology; D015232:Dinoprostone; D004789:Enzyme Activation; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007375:Interleukin-1 / Q000494:pharmacology*; D007700:Kinetics; D010003:Osteoarthritis / Q000201:enzymology / Q000378:metabolism / Q000473:pathology; D010740:Phospholipases / Q000378:metabolism*; D010741:Phospholipases A / Q000378:metabolism*; D054467:Phospholipases A2; D010960:Plasminogen Activators / Q000378:metabolism; D011458:Prostaglandins E / Q000378:metabolism; D013583:Synovial Membrane / Q000201:enzymology* / Q000378:metabolism / Q000473:pathology
D007375:Interleukin-1; D011458:Prostaglandins E; D010740:Phospholipases; D010741:Phospholipases A; D054467:Phospholipases A2; D010960:Plasminogen Activators; D015232:Dinoprostone; D002118:Calcium