The Relative Study Of The Expression Of COX-2 And 5-LOX In Respiratory Syncytial Virus-Infected Macrophages

ObjectiveTo investigate the effect of expression of Cyclooxygenase-2 (COX-2) and 5-lipoxygenase (5-LOX) and their related inflammatory mediators on RAW264.7 macrophages infected with respiratory syncytial virus (RSV) in vitro, and its related regulating mechanisms in the course of RSV infection. To provide the certain theory foundation for the mechanism of RSV induced inflammatory response and clinical treatment of RSV disease.Methods①RAW264.7 macrophages infected with RSV in vitro were used to collect cells and cellular supernatants. The expression of Cyclooxygenase-2 (COX-2) and 5-Lipoxygenase (5-LOX) mRNA and protein were evaluated by semiquantitative RT-PCR and Wesrern-blot, respectively. The concentrations of Prostaglandin E2 (PGE2) and leukotriene B4 (LTB4) in cellular supernatants were measured by ELISA assay according to the kit reference.②Furthermore, the cells infected with RSV were treated with 50μmol/L pyrrolidine dithiocarbamate (PDTC) to inhibit the activation of NF-κB. Each indices mentioned above were detected and compared with the groups that did not use PDTC inhibitor.Results①RSV infection could markedly up-regulated the expression of COX-2 mRNA and protein in RAW264.7 macrophages since 8 h after infection. In the cellular supernatants, the levels of PGE2 rose gradually. Meanwhile, the changes of each index varied significantly compared with the control group, increased obviously in a time-dependent manner.②Infections within 24 h, the expression of 5-LOX in RAW264.7 macrophages had no significant difference compared with the control group, the concentrations of LTB4 did the same too.③PDTC inhibitor could significantly down-regulate the activation of NF-κB, and the expression of COX-2 mRNA and protein were also decreased since 8 h after infection. The changes of PDTC group were significant compared with the RSV group. But PDTC inhibitor had no effect on 5-LOX expression and the level of inflammatory factors LTB4 as well.ConclusionsRSV infection macrophages could induce the expression of COX-2 in early stage, the activation of NF-κB may play an important role in the expression of COX-2. But the infection had no influence on the expression of 5-LOX in 24 h.