Fig 7. Inhibition of COX isoforms on murine norovirus (MNV) infection leads to decreased MNV replication.

(A) Cultured RAW 264.7 cells were pretreated or post-treated with noncytotoxic doses of SC-560, NS398, or indomethacin. Samples were harvested at 24 h post-infection (hpi), and the levels of viral protein VPg were determined by Western blot analysis. GAPDH was used as a loading control. (B) RAW264.7 cells were transfected with COX-1, COX-2, or scrambled (Scram) siRNAs and incubated with MNV (MOI, 1 TCID₅₀/ml) for 24 h. Western blot analysis was performed to detect MNV VPg protein. GAPDH was used as a loading control. (C) RAW 264.7 cells were mock- or post-treated with a selective COX-2 inhibitor indomethacin, or non-transfected or transfected with COX-1, COX-2, or Scram siRNAs. The cells were then incubated with MNV (MOI, 1 TCID₅₀/ml) for 24 h, and the effect of the drugs or COX-1, COX-2, or Scram siRNAs on the expression level of viral VPg protein was determined by confocal microscopy. Bar = 20 μM.