Feline calicivirus- and murine norovirus-induced COX-2/PGE2 signaling pathway has proviral effects
(A–F) RAW264.7 cells were pretreated (Pre), post-treated (Post), or pre-post-treated (Pre-Post) with non-cytotoxic doses of SC-560, NS-398, or indomethacin. At 24 h post-infection (hpi) with MNV (MOI, 1 TCID50/ml), viral titer and genome copy number were determined by TCID50/ml and quantitative real time PCR (qRT-PCR) analyses. The inhibitory effects of each drug on the viral titer or genome copy number were compared between mock- and drug-treated groups. (G and H) COX-1, COX-2, and scrambled (Scram) siRNAs were transfected in RAW264.7 cells before infection with MNV (MOI, 1 TCID50/ml). The samples were harvested at 24 hpi, and virus titer and genome copy number were determined by TCID50/ml (G) or qRT-PCR (H) analyses. The inhibitory effects of each siRNA on viral titer and genome copy number were compared between the mock- and each siRNA-transfected group. Three independent experiments were conducted and presented as means and standard errors of the mean. Statistical differences were determined using one-way analysis of variance. **p < 0.001; *** p < 0.0001.