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3 results on '"Amaral, Rafaela Bacci"'

2. Effects of Bothrops asper snake venom on the expression of cyclooxygenases and production of prostaglandins by peritoneal leukocytes in vivo, and by isolated neutrophils and macrophages in vitro

Author

Moreira, Vanessa, Gutiérrez, José María, Amaral, Rafaela Bacci, Zamunér, Stella Regina, and Teixeira, Catarina de Fátima

Subjects
Male, Snake venom, Cell Survival, Neutrophils, Macrophage, Neutrophile, Clinical Biochemistry, Prostaglandin, Pharmacology, Biology, Dinoprostone, Proinflammatory cytokine, Mice, chemistry.chemical_compound, In vivo, Crotalid Venoms, Leukocytes, Animals, Ascitic Fluid, Bothrops, Peritoneal Cavity, Prostaglandin D2, Neutrophil, Membrane Proteins, Cell Biology, Cyclooxygenases, In vitro, chemistry, Eicosanoid, Cyclooxygenase 2, Prostaglandin-Endoperoxide Synthases, Immunology, Biocatalysis, Cyclooxygenase 1, Macrophages, Peritoneal, Prostaglandins, lipids (amino acids, peptides, and proteins), Injections, Intraperitoneal
Abstract

In this study, the ability of Bothrops asper snake venom (BaV) to increase the production of prostaglandins PGE2 and PGD2 was assessed in a mouse model in vivo and in inflammatory cells in vitro. In addition, the expressions of COX-1 and COX-2 were assessed. BaV induced an increment in the in vivo synthesis of PGE2 and PGD2, together with an enhanced expression of COX-2, but not of COX-1. However, enzymatic activities of COX-1 and COX-2 were increased. Incubation of isolated macrophages and neutrophils with a sub-cytotoxic concentration of BaV in vitro resulted in increased release of PGE2 and PGD2 by macrophages and PGE2 by neutrophils, concomitantly with an increment in the expression of COX-2, but not of COX-1 by both cell types. Our results demonstrate the ability of BaV to promote the expression of COX-2 and to induce the synthesis of proinflammatory prostaglandins. Macrophages and neutrophils may be important targets for this venom under in vivo situation. UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias de la Salud::Instituto Clodomiro Picado (ICP)

Published
2009

3. A phospholipase A2 from Bothrops asper snake venom activates neutrophils in culture: Expression of cyclooxygenase-2 and PGE2 biosynthesis

Author

Moreira, Vanessa, Gutiérrez, José María, Amaral, Rafaela Bacci, Lomonte, Bruno, Purgatto, Eduardo, and Teixeira, Catarina

Subjects
*PHOSPHOLIPASE A2, *FER-de-lance, *SNAKE venom, *NEUTROPHILS, *ENZYME activation, *CYCLOOXYGENASE 2, *ENZYMES, *CHEMICAL synthesis
Abstract

Abstract: In this study, the production of prostaglandin E2 (PGE2) and up-regulation in cyclooxygenase (COX) pathway induced by a phospholipase A2 (PLA2), myotoxin-III (MT-III), purified from Bothrops asper snake venom, in isolated neutrophils were investigated. The arachidonic acid (AA) production and the participation of intracellular PLA2s (cytosolic PLA2 and Ca2+-independent PLA2) in these events were also evaluated. MT-III induced COX-2, but not COX-1 gene and protein expression in neutrophils and increased PGE2 levels. Pretreatment of neutrophils with COX-2 and COX-1 inhibitors reduced PGE2 production induced by MT-III. Arachidonyl trifluoromethyl ketone (AACOCF3), an intracellular PLA2 inhibitor, but not bromoenol lactone (BEL), an iPLA2 inhibitor, suppressed the MT-III-induced AA and PGE2 release. In conclusion, MT-III directly stimulates neutrophils inducing COX-2 mRNA and protein expression followed by production of PGE2. COX-2 isoform is preeminent over COX-1 for production of PGE2 stimulated by MT-III. PGE2 and AA release by MT-III probably is related to cPLA2 activation. [Copyright &y& Elsevier]

Published
2011
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