Viral growth factor- and STAT3 signaling-dependent elevation of the TCA cycle intermediate levels during vaccinia virus infection
Fig 6
Inhibition of the STAT3 pathway and its upstream signaling decreases citrate levels during VACV infection.
(A) Inhibition of the EGFR pathway decreases the citrate level in VACV-infected HFFs. HFFs were infected with WT VACV at an MOI of 5 in the presence or absence of 3 μM afatinib. The citrate level was measured at 4 hpi. (B) Inhibition of the MAPK pathway decreases the citrate level during VACV infection. HFFs were infected with WT VACV at an MOI of 5 in the presence or absence of 20 μM PD0325901. The citrate level was measured at 2 hpi. (C) Inhibition of the STAT3 pathway decreases the citrate level in VACV-infected cells. HFFs were infected with VACV at an MOI of 5 in the presence or absence of 3 μM stattic. The citrate level was measured at 4 hpi. (F) siRNA-mediated knockdown of STAT3. HFFs were transfected with a negative control siRNA or two specific siRNA targeting STAT3 for 48 h. Western blotting analysis was performed to measure the level of STAT3. (G) siRNA-mediated knockdown of STAT3 decreases citrate level during VACV infection. HFFs were transfected with indicated siRNAs for 48 h and then infected with an MOI of 5 of VACV for 4 h, and the citrate level was measured. All the infections were performed in media with glucose plus glutamine. Error bars represent the standard deviation of at least three biological replicates. ns, P > 0.05; *, P ≤ 0.05; **, P ≤ 0.01; ***, P ≤ 0.001.