Laboratório de Farmacologia, Instituto Butantan, Sao Paulo, Brazil; Laboratório de Imunologia Celular Aplicada à Saúde, Fundação Oswaldo Cruz Rondônia/FIOCRUZ-RO, Porto Velho, RO, Brazil; Dep. Medicina, Universidade Federal de Rondônia, UNIR, Porto Velho, RO, Brazil.
Instituto Clodomiro Picado, Facultad de Microbiología, Universidad de Costa Rica, San José, Costa Rica.
Int J Biol Macromol. 2018 Jul 1;113:575-582. doi: 10.1016/j.ijbiomac.2018.02.158. Epub 2018 Mar 6.
Phagocytosis, a process involved in host defense, requires coordination of a variety of signaling reactions. MT-II, a catalytically-inactive Lys49-PLA¸ and MT-III, an active Asp49-PLA isolated from Bothrops asper snake venom, activate phagocytosis in macrophages. In this study the signal pathways mediating zymosan phagocytosis, focusing in lipidic second messengers, were investigated. Macrophages collected from male Swiss mouse peritoneum were obtained 96h after i.p. injection of thioglycollate. Phagocytosis was evaluated with non-opsonized zymosan in the presence or absence of specific inhibitors. Data showed that both venom PLAs increased phagocytosis. Zileuton, Etoricoxib, PACOCF (5-LO, COX-2 and iPLA inhibitors, respectively), as well as WEB2170 (PAF receptor antagonist) significantly reduced phagocytosis induced by both venom PLAs. However, Indomethacin (COX-1/COX-2 inhibitor) and Montelukast (CysL receptor antagonist) did not affect the toxins-induced phagocytosis. Moreover, while PACOCF3 (iPLA inhibitor), reduced the phagocytosis induced by MT-II and MT-III, AACOCF (cPLA inhibitor) significantly reduced the MT-II, but not MT-III-induced phagocytosis. These data suggest the effect of both sPLAs depends on iPLA and that the effect of MT-II depends on activation of cPLA. COX-2 and 5-LO-derived metabolites as well as PAF are involved in the signaling events required for phagocytosis induced by both venom sPLAs.
吞噬作用是宿主防御的一个过程，需要协调多种信号反应。MT-II，一种无催化活性的 Lys49-PLA2，和 MT-III，一种从 Bothrops asper 蛇毒中分离出的有活性的 Asp49-PLA2，都能激活巨噬细胞的吞噬作用。在这项研究中，研究了介导酵母聚糖吞噬作用的信号通路，重点是脂质第二信使。从雄性瑞士鼠腹膜中收集巨噬细胞，在腹腔注射硫代乙醇酸盐 96 小时后获得。在存在或不存在特异性抑制剂的情况下，用非调理酵母聚糖评估吞噬作用。数据显示，两种毒液 PLA2 都能增加吞噬作用。齐留通、依托考昔、PACOCF（分别为 5-LO、COX-2 和 iPLA 抑制剂）以及 WEB2170（PAF 受体拮抗剂）显著降低了两种毒液 PLA2 诱导的吞噬作用。然而，吲哚美辛（COX-1/COX-2 抑制剂）和孟鲁司特（CysL 受体拮抗剂）并没有影响毒素诱导的吞噬作用。此外，虽然 PACOCF3（iPLA 抑制剂）降低了 MT-II 和 MT-III 诱导的吞噬作用，但 AACOCF（cPLA 抑制剂）显著降低了 MT-II，但不降低 MT-III 诱导的吞噬作用。这些数据表明，两种 sPLA2 的作用都依赖于 iPLA，而 MT-II 的作用依赖于 cPLA 的激活。COX-2 和 5-LO 衍生的代谢物以及 PAF 参与了两种毒液 sPLA2 诱导的吞噬作用所需的信号事件。
