The Production Mechanism of TNF-alpha and IL-6 by Group IIA Phospholipase A2 / 영남의대학술지

ABSTRACT

BACKGROUND: Secretory phospholipase A2 (sPLA2) are a group of extracellular enzymes that release fatty acids at the sn-2 position of phospholipids. Group IIA sPLA2 (sPLA2-IIA) has been detected in the inflammatory fluids, and its plasma level increases in the inflammatory disease. This study examined the effect of sPLA2-IIA on mouse macropahges in order to investigate the potential mechanism of sPLA2-induced inflammation. MATERIALS AND METHODS: Wild type PLA2 and mutant H48Q PLA2 were purified from HEK293 cells transfected with the corresponding plasmids, and the PLA2 activities were measured using 1-palmitoyl-2-[1- (14) C]linoleoyl-3-phosphatidylethanolamine as substrates. The TNF-alpha and IL-6 released in the supernatants were determined by ELISA. In addition, the TNF-alpha and IL-6 mRNA were analyzed by RT-PCR. RESULTS: sPLA2-IIA stimulated the production of TNF-alpha and IL-6 in a dose- and time-dependent manner. In addition, the effect of sPLA2-IIA on cytokine production from the macrophage was found to be associated with the accumulation of their specific mRNA. The mRNA levels of TNF-alpha and IL-6 peaked at 2 and 6 hours in a time-dependent manner, respectively. CONCLUSION: In conclusion, the production of proinflammatory cytokine might be mediated by the binding of sPLA2-IIA to the receptors.