Cytosolic phospholipase A2-α participates in lipid body formation and PGE2 release in human neutrophils stimulated with an l-amino acid oxidase from Calloselasma rhodostoma venom
Mauro Valentino Paloschi, Jéssica Amaral Lopes, Charles Nunes Boeno, Milena Daniela Souza Silva, Jaína Rodrigues Evangelista, Adriana S. Pontes, Sulamita da Silva Setúbal, Cristina Matiele Alves Rego, Neriane Monteiro Néry, Alex Augusto Ferreira e Ferreira, Weverson Luciano Pires, Kátia Paula Felipin, Gabriel Eduardo Melim Ferreira, Patrı́cia T. Bozza, Juliana Pavan Zuliani
Abstract
Abstract Cr-LAAO, an l -amino acid oxidase isolated from Calloselasma rhodosthoma snake venom, has been demonstrated as a potent stimulus for neutrophil activation and inflammatory mediator production. However, the mechanisms involved in Cr-LAAO induced neutrophil activation has not been well characterized. Here we investigated the mechanisms involved in Cr-LAAO-induced lipid body (also known as lipid droplet) biogenesis and eicosanoid formation in human neutrophils. Using microarray analysis, we show for the first time that Cr-LAAO plays a role in the up-regulation of the expression of genes involved in lipid signalling and metabolism. Those include different members of phospholipase A 2, mostly cytosolic phospholipase A 2 -α (cPLA 2 -α); and enzymes involved in prostaglandin synthesis including cyclooxygenases 2 (COX-2), and prostaglandin E synthase (PTGES). In addition, genes involved in lipid droplet formation, including perilipin 2 and 3 (PLIN 2 and 3) and diacylglycerol acyltransferase 1 (DGAT1), were also upregulated. Furthermore, increased phosphorylation of cPLA 2 -α, lipid droplet biogenesis and PGE 2 synthesis were observed in human neutrophils stimulated with Cr-LAAO. Treatment with cPLA 2 -α inhibitor (CAY10650) or DGAT-1 inhibitor (A922500) suppressed lipid droplets formation and PGE 2 secretion. In conclusion, we demonstrate for the first time the effects of Cr-LAAO to regulate neutrophil lipid metabolism and signalling.