Human neutrophil migration in vitro induced by secretory phospholipases A2: a role for cell surface glycosaminoglycans.
The purpose of this study was to examine the ability of type I- (porcine pancreas and Naja mocambique mocambique venom), type II- (bothropstoxin-I, bothropstoxin-II, and piratoxin-I), and type III- (Apis mellifera venom) secretory phospholipases A2 (sPLA2s) to induce human neutrophil chemotaxis, and the role of the cell surface proteoglycans, leukotriene B4 (LTB4), and platelet-activating factor (PAF), in mediating this migration. The neutrophil chemotaxis assays were performed by using a 48-well microchemotaxis chamber. Piratoxin-I, bothropstoxin-I, N. m. mocambique venom PLA2 (10-1000 microg/mL each), bothropstoxin-II (30-1000 microg/mL), porcine pancreas PLA2 (0.3-30 microg/mL), and A. mellifera venom PLA2 (30-300 microg/mL) caused concentration-dependent neutrophil chemotaxis. Heparin (10-300 U/mL) concentration-dependently inhibited the neutrophil migration induced by piratoxin-I, bothropstoxin-II, and N. m. mocambique and A. mellifera venom PLA2s (100 microg/mL each), but failed to affect the migration induced by porcine pancreas PLA2. Heparan sulfate (300 and 1000 microg/mL) inhibited neutrophil migration induced by piratoxin-I, whereas dermatan sulfate and chondroitin sulfate (30-1000 microg/mL each) had no effect. Heparitinase I and heparinase (300 mU/mL each) inhibited by 41.5 and 47%, respectively, piratoxin-I-induced chemotaxis, whereas heparitinase II and chondroitinase AC failed to affect the chemotaxis. The PAF receptor antagonist WEB 2086 (3-[4-(2-chlorophenyl)-9-methyl-6H-thienol-[3,2-f] -triazolo-[4,3-a] -diazepine-2-yl]-1-(4-morpholynil)-1-propionate) (0.1-10 microM) and the LTB4 synthesis inhibitor AA-861 [2-(12-hydroxydodeca-5,10-diynyl)-3,5,6-trimethyl-1,4-benzoquinone] (0.1-10 microM) significantly inhibited the piratoxin-I-induced chemotaxis. Piratoxin-I (30-300 microg/mL) caused a concentration-dependent release of LTB4. Our results suggest that neutrophil migration in response to sPLA2s is independent of PLA activity, and involves an interaction of sPLA2s with cell surface heparin/heparan binding sites triggering the release of LTB4 and PAF.
Gambero
Alessandra
A
Department of Pharmacology, Faculty of Medical Sciences, UNICAMP, PO Box 6111, 13081-970, Campinas, SP, Brazil.
Landucci
Elen C T
EC
Toyama
Marcos H
MH
Marangoni
Sergio
S
Giglio
Jose R
JR
Nader
Helena B
HB
Dietrich
Carl P
CP
De Nucci
Gilberto
G
Antunes
Edson
E
D001381:Azepines / Q000494:pharmacology; D016227:Benzoquinones / Q000494:pharmacology; D002465:Cell Movement / Q000187:drug effects / Q000502:physiology*; D002633:Chemotaxis / Q000502:physiology; D002808:Chondroitin Lyases / Q000494:pharmacology; D005417:Flavobacterium / Q000201:enzymology; D006025:Glycosaminoglycans / Q000502:physiology*; D006493:Heparin / Q000494:pharmacology; D019763:Heparin Lyase / Q000494:pharmacology; D006801:Humans; D066298:In Vitro Techniques; D007975:Leukotriene B4 / Q000378:metabolism; D016859:Lipoxygenase Inhibitors / Q000494:pharmacology; D009504:Neutrophils / Q000187:drug effects / Q000201:enzymology* / Q000502:physiology; D010741:Phospholipases A / Q000502:physiology*; D054467:Phospholipases A2; D010975:Platelet Aggregation Inhibitors / Q000494:pharmacology; D011133:Polysaccharide-Lyases / Q000494:pharmacology; D014230:Triazoles / Q000494:pharmacology
D001381:Azepines; D016227:Benzoquinones; D006025:Glycosaminoglycans; D016859:Lipoxygenase Inhibitors; D010975:Platelet Aggregation Inhibitors; D014230:Triazoles; C052518:WEB 2086; D007975:Leukotriene B4; C036837:2,3,5-trimethyl-6-(12-hydroxy-5,10-dodecadiynyl)-1,4-benzoquinone; D006493:Heparin; D010741:Phospholipases A; D054467:Phospholipases A2; D002808:Chondroitin Lyases; D011133:Polysaccharide-Lyases; D019763:Heparin Lyase; C021349:heparitinsulfate lyase