The role of phospholipases A(2) in the stimulation of neutrophil motility by cobra venoms

Sundell, I. B., Aziz, K. A., Zuzel, M. and Theakston, R.David G. (2003) 'The role of phospholipases A(2) in the stimulation of neutrophil motility by cobra venoms'. Toxicon, Vol 41, Issue 4, pp. 459-468.

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Abstract

Neutrophil (PMN) accumulation frequently occurs at the site of snakebite as part of the inflammatory response to envenoming. We demonstrate here that the venoms of the cobras, Naja naja and N. mossambica, and two purified venom phospholipase A(2)s (PLA(2)s) isolated from the latter venom, stimulate CD11b translocation from the PMN granule store to the plasma membrane and enhance neutrophil motility on collagen-coated surfaces. These effects were partially attenuated by the PLA(2) inhibitor, aristolochic acid, and almost completely abolished by the specific cytosolic PLA(2) inhibitor, methylarachidonylfluorophosphonate (MAFP). Annexin V and inhibitors of collagenase, cyclo-oxygenase and lipo-oxygenase, all inhibited PMN motility to a variable extent. FACS analysis and confocal microscopy showed that Annexin V interfered with binding and rapid endocytosis of the venom PLA(2). These results indicate that venom and venom PLA(2) preparations first caused a non-enzymatic stimulation of PMN leading to the activation of cytosolic PMN PLA(2) and production of arachidonate metabolites involved in stimulation of PMN degranulation and motility. The evidence suggests that venom PLA(2) then interacts with anionic phospholipids exposed on stimulated PMN, becomes endocytosed, and then contributes itself to the production of chemoattractants responsible for PMN accumulation at the site of the snakebite. (C) 2003 Elsevier Science Ltd. All rights reserved.

Item Type:	Article
Subjects:	QU Biochemistry > Enzymes > QU 143 Enzyme inhibitors WD Disorders of Systemic, Metabolic or Environmental Origin, etc > Animal Poisons > WD 410 Reptiles
Digital Object Identifer (DOI):	https://doi.org/10.1016/s0041-0101(02)00365-3
Depositing User:	Martin Chapman
Date Deposited:	23 May 2013 14:18
Last Modified:	25 Nov 2024 08:17
URI:	https://archive.lstmed.ac.uk/id/eprint/2675

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