กระบวนการอักเสบแบบเฉียบพลันของน้ำพิษ Tetraponera rufonigra ต่อเซลล์เพาะเลี้ยงมาโครฟาจ RAW264.7 ผ่านวิถีไซโคออกซีจีเนส- 2

Abstract

Tetraponera rufonigra (Hymenoptera, Formicidae, Pseudomyrmecinae) is well-known as the aggressive stinger and important in medicine since its toxin could induce anaphylaxtic reaction. Normally, ant venoms are consisted of varieties of proteins, alkaloids, hydrocarbon compounds and formic acid. These substances exert adverse effects especially paralytic, cytolytic, hemolytic and allergenic effects. The study of venom composition and its mechanisms have not been studied. The aim of this research was to identify venom protein composition and mechanism of inflammation by using RAW 264.7 macrophage cell lines. The ant samples were collected at Omkoi District, Chiang Mai Province, the genus and species were identified by taxonomist at the Natural History Museum. The protein composition was separated by electrophoresis (SDS-PAGE) technique and was identified by LC-MS/MS. The results showed that the T. rufonigra venom composed of seven protein toxin groups including venom protein (protein 5NUC, prolyl endopeptidase-like, aminopeptidase N, trypsin-3, venom protein, Phospholipase A2), transcription activator/regulation protein (transcriptional activator cubitus interruptus), cell cycle control protein (growth arrest and DNA damage-inducible proteins-interacting protein 1), transporter protein (ATP-binding cassette sub-family A member 3), structural protein (Paramyosin, long form/short form), ligand protein (protein jagged-1) and hypothetical protein. Those proteins used for prey tissue degradation and related to the ant carnivore behavior. Phospholipase A2 (PLA2) was major component in the venom and showed clear zone on egg yolk agar plates. This venom induced cytotoxic effect on RAW264.7 in a dose and time dependent manner. After RAW 264.7 macrophage cell lines were treated with the venom, cyclooxygenase-2 (COX-2) and plostaglandin E2 (PGE2) level were increased at first hour, which correlated with up-regulation of COX-2 (3-folds), followed increase 27-folds in 6 hours. Moreover, the microsomal prostaglandin E synthase-1 (mPGES-1) expression was slightly increased at first hour, following significantly increased 12 hours. The cytosolic phospholipases A2 (cPLA2) expression was not changed after treatment with the venom until 12 hours. The results presented that, the ant venom was induce inflammation in direct pathway though COX-2 and mPGES-1 expression. In this study only investigated mechanism of the in-vitro inflammatory by using RAW 264.7 macrophage cell line. Future study should be evaluated in-vivo to give more details for prevention and treatment exposure of T. rufonigra venom intoxication.