Autor(es)

Zuliani, Juliana Pavan ; Yamanouye, Norma ; Gutierrez, Jose Maria ; Teixeira, Catarina

• Tipo de documento: Artigo Científico
• Fonte: Toxicon; v. 247, p. 10-pg., 2024-06-22.

Resumo

Phagocytosis, an essential process for host defense, requires the coordination of a variety of signaling reactions. MT -II, an enzymatically inactive Lys49 phospholipase A 2 (PLA 2 ) homolog, and MT -III, a catalytically -active Asp49 PLA 2 , are known to activate phagocytosis in macrophages. In this study, the signaling pathways mediating phagocytosis, focusing on protein kinases, were investigated. Macrophages from male Swiss mice peritoneum were obtained 96 h after intraperitoneal thioglycolate injection. Phagocytosis was evaluated using nonopsonized zymosan particles in the presence or absence of specific inhibitors, as well as PKC and PKC- alpha localization by confocal microscopy. Moreover, protein kinase C (PKC) activity was assessed by gamma P 32 ATP in macrophages stimulated by both PLA 2 s. Data showed that both sPLA 2 s increased phagocytosis. Cytochalasin D, staurosporine/H7, wortmannin, and herbimycin, inhibitors of actin polymerization, PKC, phosphoinositide 3-kinase (PI3K), and protein tyrosine kinase (PTK), respectively, significantly reduced phagocytosis induced by both PLA 2 s. PKC activity was increased in macrophages stimulated by both PLA 2 s. Actin polymerization and talin were evidenced by immunofluorescence and talin was recruited 5 min after both PLA 2 s stimulation. PKC and PKC- alpha localization within the cell were increased after 60 min of MT -II and MT -III stimulation. These data suggest that the effect of both PLA 2 s depends on actin cytoskeleton rearrangements and the activation of PKC, PI3K, and PTK signaling events required for phagocytosis. (AU)

• Processo FAPESP: 02/13863-2 - Efeitos dos venenos de Bothrops asper e de Crotalus durissus terrificus, das miotoxinas MT-II e MT-III, crotoxina e crotapotina sobre a liberação de prostanóides e a expressão de ciclooxigenases: estudos in vivo e in vitro
• Beneficiário: Catarina de Fatima Pereira Teixeira
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 02/01009-7 - Estudos da sinalização intracelular e proteínas de citoesqueleto no processo de fagocitose por macrófagos induzido por duas toxinas com estrutura de Fosfolipase A2 (mt-ii e MT-III), isoladas no veneno de Bothrops asper
• Beneficiário: Juliana Pavan Zuliani
• Modalidade de apoio: Bolsas no Brasil - Doutorado